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Search for "recyclable" in Full Text gives 89 result(s) in Beilstein Journal of Organic Chemistry.
Reaction of indoles with aromatic fluoromethyl ketones: an efficient synthesis of trifluoromethyl(indolyl)phenylmethanols using K2CO3/n-Bu4PBr in water
- Thanigaimalai Pillaiyar,
- Masoud Sedaghati and
- Gregor Schnakenburg
Beilstein J. Org. Chem. 2020, 16, 778–790, doi:10.3762/bjoc.16.71
- recyclable of the catalyst (Figure 2C). Results and Discussion The optimization studies were carried out with model substrates 5-methoxyindole (1a, 3.4 mmol) and 2,2,2-trifluoroacetophenone (2a, 3.70 mmol) in water (5 mL, see Table 1 for results). Using water as a solvent has the advantage that the formed
Graphical Abstract
Figure 1: Structures of trifluoromethylated compounds and their biological activities.
Figure 2: Synthetic approaches toward hydroxyalkylation of indole.
Figure 3: Structures of heterocycles that did not react with ketone 2a.
Scheme 1: Gram-scale synthesis of 2,2,2-trifluoro-1-(1H-indol-3-yl)-1-phenylethan-1-ols (3a and 3p).
Figure 4: Recyclability of the catalytic system n-Bu4PBr/K2CO3 for the preparation of 2,2,2-trifluoro-1-(5-me...
Scheme 2: Synthesis of trifluoromethylated unsymmetrical 3,3'- and 3,6'-DIMs (9–11).
Scheme 3: Proposed mechanism for the preparation of 3a as an example.
Scheme 4: Control experiments.
Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules
- Valerian Dragutan,
- Ileana Dragutan,
- Albert Demonceau and
- Lionel Delaude
Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68
- dihydroartemisinic acid (DHAA) [64][65]. Also, high efficient and recyclable catalytic systems based on metal-organic frameworks (MOFs) have also been reported for the tandem hemisynthesis of artemisinin [66]. In a remarkable work, this antimalarial drug was obtained by a new route involving enyne metathesis as the
Graphical Abstract
Scheme 1: Intramolecular (A) and intermolecular (B) enyne metathesis reactions.
Scheme 2: Ene–yne and yne–ene mechanisms for intramolecular enyne metathesis reactions.
Scheme 3: Metallacarbene mechanism in intermolecular enyne metathesis.
Scheme 4: The Oguri strategy for accessing artemisinin analogs 1a–c through enyne metathesis.
Scheme 5: Access to the tetracyclic core of nanolobatolide (2) via tandem enyne metathesis followed by an Eu(...
Scheme 6: Synthesis of (−)-amphidinolide E (3) using an intermolecular enyne metathesis as the key step.
Scheme 7: Synthesis of amphidinolide K (4) by an enyne metathesis route.
Scheme 8: Trost synthesis of des-epoxy-amphidinolide N (5) [72].
Scheme 9: Enyne metathesis between the propargylic derivative and the allylic alcohol in the synthesis of the...
Scheme 10: Synthetic route to amphidinolide N (6a).
Scheme 11: Synthesis of the stereoisomeric precursors of amphidinolide V (7a and 7b) through alkyne ring-closi...
Scheme 12: Synthesis of the anthramycin precursor 8 from ʟ-methionine by a tandem enyne metathesis–cross metat...
Scheme 13: Synthesis of (−)‐clavukerin A (9) and (−)‐isoclavukerin A (10) by an enyne metathesis route startin...
Scheme 14: Synthesis of (−)-isoguaiene (11) through an enyne metathesis as the key step.
Scheme 15: Synthesis of erogorgiaene (12) by a tandem enyne metathesis/cross metathesis sequence using the sec...
Scheme 16: Synthesis of (−)-galanthamine (13) from isovanilin by an enyne metathesis.
Scheme 17: Application of enyne metathesis for the synthesis of kempene diterpenes 14a–c.
Scheme 18: Synthesis of the alkaloid (+)-lycoflexine (15) through enyne metathesis.
Scheme 19: Synthesis of the AB subunits of manzamine A (16a) and E (16b) by enyne metathesis.
Scheme 20: Jung's synthesis of rhodexin A (17) by enyne metathesis/cross metathesis reactions.
Scheme 21: Total synthesis of (−)-flueggine A (18) and (+)-virosaine B (19) from Weinreb amide by enyne metath...
Scheme 22: Access to virgidivarine (20) and virgiboidine (21) by an enyne metathesis route.
Scheme 23: Enyne metathesis approach to (−)-zenkequinone B (22).
Scheme 24: Access to C-aryl glycoside 23 by an intermolecular enyne metathesis/Diels–Alder cycloaddition.
Scheme 25: Synthesis of spiro-C-aryl glycoside 24 by a tandem intramolecular enyne metathesis/Diels–Alder reac...
Scheme 26: Pathways to (−)-exiguolide (25) by Trost’s Ru-catalyzed enyne cross-coupling and cross-metathesis [94].
A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions
- Pezhman Shiri and
- Jasem Aboonajmi
Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52
- methodologies. These inorganic supported nanocatalysts have been found to be efficient, environmentally friendly, recyclable, and durable. In addition, one of the vital issues for expanding new, stable, and reusable catalysts is the discovery of unique catalysts. The basis and foundation of this review article
- applications that focused on the title catalysts in CuAAC reactions. Review Copper anchored on functionalized silica materials: efficient and recyclable catalysts for CuAAC reactions In recent years, silica or silicon dioxide nanomaterials have received much attention from researchers and industry and have
- in HCl/H2O using 0.1 mol % of Cu@PyIm–SBA-15 (69, Scheme 12). Copper anchored on functionalized carbon materials: efficient and recyclable catalysts for CuAAC reactions Carbon nanomaterials have attracted the interest of researchers due to the high electrical and thermal conductivities, low
Graphical Abstract
Scheme 1: Chemical structure of the catalysts 1a and 1b and their catalytic application in CuAAC reactions.
Scheme 2: Synthetic route to the catalyst 11 and its catalytic application in CuAAC reactions.
Scheme 3: Synthetic route of dendrons, illustrated using G2-AMP 23.
Scheme 4: The catalytic application of CuYAu–Gx-AAA–SBA-15 in a CuAAC reaction.
Scheme 5: Synthetic route to the catalyst 36.
Scheme 6: Application of the catalyst 36 in CuAAC reactions.
Scheme 7: The synthetic route to the catalyst 45 and catalytic application of 45 in “click” reactions.
Scheme 8: Synthetic route to the catalyst 48 and catalytic application of 48 in “click” reactions.
Scheme 9: Synthetic route to the catalyst 58 and catalytic application of 58 in “click” reactions.
Scheme 10: Synthetic route to the catalyst 64 and catalytic application of 64 in “click” reactions.
Scheme 11: Chemical structure of the catalyst 68 and catalytic application of 68 in “click” reactions.
Scheme 12: Chemical structure of the catalyst 69 and catalytic application of 69 in “click” reactions.
Scheme 13: Synthetic route to, and chemical structure of the catalyst 74.
Scheme 14: Application of the cayalyst 74 in “click” reactions.
Scheme 15: Synthetic route to, and chemical structure of the catalyst 78 and catalytic application of 78 in “c...
Scheme 16: Synthetic route to the catalyst 85.
Scheme 17: Application of the catalyst 85 in “click” reactions.
Scheme 18: Synthetic route to the catalyst 87 and catalytic application of 87 in “click” reactions.
Scheme 19: Chemical structure of the catalyst 88 and catalytic application of 88 in “click” reactions.
Scheme 20: Synthetic route to the catalyst 90 and catalytic application of 90 in “click” reactions.
Scheme 21: Synthetic route to the catalyst 96 and catalytic application of 96 in “click” reactions.
Scheme 22: Synthetic route to the catalyst 100 and catalytic application of 100 in “click” reactions.
Scheme 23: Synthetic route to the catalyst 102 and catalytic application of 23 in “click” reactions.
Scheme 24: Synthetic route to the catalysts 108–111.
Scheme 25: Catalytic application of 108–111 in “click” reactions.
Scheme 26: Synthetic route to the catalyst 121 and catalytic application of 121 in “click” reactions.
Scheme 27: Synthetic route to 125 and application of 125 in “click” reactions.
Scheme 28: Synthetic route to the catalyst 131 and catalytic application of 131 in “click” reactions.
Scheme 29: Synthetic route to the catalyst 136.
Scheme 30: Application of the catalyst 136 in “click” reactions.
Scheme 31: Synthetic route to the catalyst 141 and catalytic application of 141 in “click” reactions.
Scheme 32: Synthetic route to the catalyst 144 and catalytic application of 144 in “click” reactions.
Scheme 33: Synthetic route to the catalyst 149 and catalytic application of 149 in “click” reactions.
Scheme 34: Synthetic route to the catalyst 153 and catalytic application of 153 in “click” reactions.
Scheme 35: Synthetic route to the catalyst 155 and catalytic application of 155 in “click” reactions.
Scheme 36: Synthetic route to the catalyst 157 and catalytic application of 157 in “click” reactions.
Scheme 37: Synthetic route to the catalyst 162.
Scheme 38: Application of the catalyst 162 in “click” reactions.
Scheme 39: Synthetic route to the catalyst 167 and catalytic application of 167 in “click” reactions.
Scheme 40: Synthetic route to the catalyst 169 and catalytic application of 169 in “click” reactions.
Scheme 41: Synthetic route to the catalyst 172.
Scheme 42: Application of the catalyst 172 in “click” reactions.
Oligomeric ricinoleic acid preparation promoted by an efficient and recoverable Brønsted acidic ionic liquid
- Fei You,
- Xing He,
- Song Gao,
- Hong-Ru Li and
- Liang-Nian He
Beilstein J. Org. Chem. 2020, 16, 351–361, doi:10.3762/bjoc.16.34
- difficulties. Therefore, it is urgently desirable to develop an efficient, green and recyclable catalyst and design simple operating procedures for the preparation of estolides oligomeric ricinoleic acid. Ionic liquids (ILs) have been proved to be efficient catalysts in various organic syntheses due to the
Graphical Abstract
Scheme 1: [HSO3-BDBU]H2PO4-promoted oligomerization and separation.
Scheme 2: Structures of ILs used in this work.
Figure 1: Monitoring oligomerization process by 1H NMR (400 MHz, CDCl3).
Figure 2: Reusability of the IL catalyst. Reaction conditions: 10 g (30 mmol) ricinoleic acid, 190 °C, 6 h, 5...
Figure 3: 1H NMR (400 MHz, DMSO-d6) spectra of [HSO3-BDBU]H2PO4: a) Fresh one; b) used one after five cycles.
Scheme 3: Proposed mechanism for [HSO3-BDBU]H2PO4 catalyzed oligomeric ricinoleic acid synthesis.
Synthesis of 3-alkenylindoles through regioselective C–H alkenylation of indoles by a ruthenium nanocatalyst
- Abhijit Paul,
- Debnath Chatterjee,
- Srirupa Banerjee and
- Somnath Yadav
Beilstein J. Org. Chem. 2020, 16, 140–148, doi:10.3762/bjoc.16.16
- recyclable up to four cycles. Also, the catalyst acts through a heterogeneous mechanism, which has been proven by various techniques, such as ICPMS and three-phase tests. The nature of the Ru nanocatalyst surface has also been thoroughly examined by various techniques, and it has been found that the oxides
- reaction of aza compounds [43][44]. Again, a Ru nanoparticle-catalysed C–H selenylation of indoles was reported by Lin et al. [45]. Herein, we report the Ru-catalysed regioselective synthesis of C3 alkenylindoles using a near-naked, surfactant-free, and recyclable Ru nanocatalyst in a heterogeneous manner
Graphical Abstract
Figure 1: Biologically and medicinally important 3-alkenylindoles.
Scheme 1: a) Previous and b) present work related to the synthesis of 3-alkenylindoles.
Scheme 2: Substrate scope for the C–H alkenylation of the indoles 1. Reaction conditions: 1 (1 mmol), 2 (2 mm...
Scheme 3: a) Three-phase test to determine a homogeneous or heterogeneous catalytic mechanism of action for t...
Scheme 4: Probable catalytic mechanism for the transformation of 1a by the RuNC.
Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups
- Xiaowei Li,
- Xiaolin Shi,
- Xiangqian Li and
- Dayong Shi
Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218
- the alkyl radical species B from substrate A and 2) fluorination of the alkyl radical species B with CuF2, which is in situ-generated from the reaction of CuXBr and CsF with the aid of an amide group, gives the desired product and recyclable CuF. Csp2–H bond formation catalyzed by Cu catalysts: In
- trifluoromethylation of imidazoheterocycles with a recyclable mixed medium of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) and water (Scheme 81). By following this method, diverse trifluoromethylated imidazoheterocycles were obtained in up to 80% yield. The method features a green and recyclable solvent
Graphical Abstract
Scheme 1: The main three strategies of fluorination: nucleophilic, electrophilic and radical fluorination.
Scheme 2: Doyle’s Pd-catalyzed fluorination of allylic chlorides.
Scheme 3: Allylic fluorination of 2- and 3-substituted propenyl esters.
Scheme 4: Regioselective allylic fluorination of cinnamyl phosphorothioate esters.
Scheme 5: Palladium-catalyzed aliphatic C–H fluorination reported by Doyle.
Scheme 6: Pd-catalyzed enantioselective fluorination of α-ketoesters followed by stereoselective reduction to...
Scheme 7: Pd-catalyzed C(sp3)–H fluorination of oxindoles.
Scheme 8: C–H fluorination of 8-methylquinoline derivatives with F− reagents.
Scheme 9: Fluorination of α-cyano acetates reported by van Leeuwen.
Scheme 10: The catalytic enantioselective electrophilic C–H fluorination of α-chloro-β-keto phosphonates.
Scheme 11: Fluorination of unactivated C(sp3)–H bonds directed by the bidentate PIP auxiliary.
Scheme 12: Fluorination of C(sp3)–H bonds at the β-position of carboxylic acids.
Scheme 13: Enantioselective benzylic C–H fluorination with a chiral transient directing group.
Scheme 14: Microwave-heated Pd-catalyzed fluorination of aryl alcohols.
Scheme 15: Fluorination of aryl potassium trifluoroborates.
Scheme 16: C(sp2)–F bond formation using precatalyst [L·Pd]2(cod).
Scheme 17: Pd-catalyzed fluorination of (hetero)aryl triflates and bromides.
Scheme 18: The Pd-catalyzed C–H fluorination of arenes with Selectfluor/NFSI.
Scheme 19: Pd(II)-catalyzed ortho-monofluorination protocol for benzoic acids.
Scheme 20: Pd-catalyzed C(sp2)–H bond fluorination of 2-arylbenzothiazoles.
Scheme 21: Nitrate-promoted fluorination of aromatic and olefinic C(sp2)–H bonds and proposed mechanism.
Scheme 22: Fluorination of oxalyl amide-protected benzylamine derivatives.
Scheme 23: C–H fluorination of benzaldehydes with orthanilic acids as transient directing group.
Scheme 24: Pd(II)-catalyzed aryl C–H fluorination with various directing groups.
Scheme 25: Cu-catalyzed aliphatic, allylic, and benzylic fluorination.
Scheme 26: Cu-catalyzed SN2 fluorination of primary and secondary alkyl bromides.
Scheme 27: Copper-catalyzed fluorination of alkyl triflates.
Scheme 28: Cu-catalyzed fluorination of allylic bromides and chlorides.
Scheme 29: Synthetic strategy for the fluorination of active methylene compounds.
Scheme 30: Fluorination of β-ketoesters using a tartrate-derived bidentate bisoxazoline-Cu(II) complex.
Scheme 31: Highly enantioselective fluorination of β-ketoesters and N-Boc-oxindoles.
Scheme 32: Amide group-assisted site-selective fluorination of α-bromocarbonyl compounds.
Scheme 33: Cu-mediated aryl fluorination reported by Sanford [77].
Scheme 34: Mono- or difluorination reactions of benzoic acid derivatives.
Scheme 35: Cu-catalyzed fluorination of diaryliodonium salts with KF.
Scheme 36: Copper(I)-catalyzed cross-coupling of 2-pyridylaryl bromides.
Scheme 37: AgNO3-catalyzed decarboxylative fluorination of aliphatic carboxylic acids.
Scheme 38: The Mn-catalyzed aliphatic and benzylic C–H fluorination.
Scheme 39: Iron(II)-promoted C–H fluorination of benzylic substrates.
Scheme 40: Ag-catalyzed fluorodecarboxylation of carboxylic acids.
Scheme 41: Vanadium-catalyzed C(sp3)–H fluorination.
Scheme 42: AgNO3-catalyzed radical deboronofluorination of alkylboronates and boronic acids.
Scheme 43: Selective heterobenzylic C–H fluorination with Selectfluor reported by Van Humbeck.
Scheme 44: Fe(II)-catalyzed site-selective fluorination guided by an alkoxyl radical.
Scheme 45: Fluorination of allylic trichloroacetimidates reported by Nguyen et al.
Scheme 46: Iridium-catalyzed fluorination of allylic carbonates with TBAF(t-BuOH)4.
Scheme 47: Iridium-catalyzed asymmetric fluorination of allylic trichloroacetimidates.
Scheme 48: Cobalt-catalyzed α-fluorination of β-ketoesters.
Scheme 49: Nickel-catalyzed α-fluorination of various α-chloro-β-ketoesters.
Scheme 50: Ni(II)-catalyzed enantioselective fluorination of oxindoles and β-ketoesters.
Scheme 51: Scandium(III)-catalyzed asymmetric C–H fluorination of unprotected 3-substituted oxindoles.
Scheme 52: Iron-catalyzed directed C–H fluorination.
Scheme 53: Electrophilic silver-catalyzed Ar–F bond-forming reaction from arylstannanes.
Figure 1: Nucleophilic, electrophilic and radical CF3 sources.
Scheme 54: Cu(I)-catalyzed allylic trifluoromethylation of unactivated terminal olefins.
Scheme 55: Direct copper-catalyzed trifluoromethylation of allylsilanes.
Scheme 56: Cupper-catalyzed enantioselective trifluoromethylation of five and six-membered ring β-ketoesters.
Scheme 57: Cu-catalyzed highly stereoselective trifluoromethylation of secondary propargyl sulfonates.
Scheme 58: Remote C(sp3)–H trifluoromethylation of carboxamides and sulfonamides.
Scheme 59: Trifluoromethylation of allylsilanes with photoredox catalysis.
Scheme 60: Ag-catalyzed decarboxylative trifluoromethylation of aliphatic carboxylic acids in aqueous CH3CN.
Scheme 61: Decarboxylative trifluoromethylation of aliphatic carboxylic acids via combined photoredox and copp...
Scheme 62: Palladium-catalyzed Ar–CF3 bond-forming reaction.
Scheme 63: Palladium-catalyzed trifluoromethylation of arenes with diverse heterocyclic directing groups.
Scheme 64: Pd-catalyzed trifluoromethylation of indoles as reported by Liu.
Scheme 65: Pd-catalyzed trifluoromethylation of vinyl triflates and vinyl nonaflates.
Scheme 66: Pd(II)-catalyzed ortho-trifluoromethylation of aromatic C–H bonds.
Scheme 67: Visible-light-induced Pd(OAc)2-catalyzed ortho-trifluoromethylation of acetanilides with CF3SO2Na.
Scheme 68: CuI-catalyzed trifluoromethylation of aryl- and alkenylboronic acids.
Scheme 69: Cu-catalyzed trifluoromethylation of aryl- and vinylboronic acids.
Scheme 70: Copper-catalyzed trifluoromethylation of α,β-unsaturated carboxylic acids.
Scheme 71: Formation of C(sp2)–CF3 bond catalyzed by copper(I) complex.
Scheme 72: Loh’s Cu(I)-catalyzed trifluoromethylation of enamides and electron-deficient alkenes.
Scheme 73: Copper and iron-catalyzed decarboxylative tri- and difluoromethylation.
Scheme 74: Cu-catalyzed trifluoromethylation of hydrazones developed by Bouyssi.
Scheme 75: Cu(I)-catalyzed trifluoromethylation of terminal alkenes.
Scheme 76: Cu/Ag-catalyzed decarboxylative trifluoromethylation of cinnamic acids.
Scheme 77: Copper-catalyzed direct alkenyl C–H trifluoromethylation.
Scheme 78: Copper(I/II)-catalyzed direct trifluoromethylation of styrene derivatives.
Scheme 79: Regioselective trifluoromethylation of pivalamido arenes and heteroarenes.
Scheme 80: Synthesis of trifluoromethylquinones in the presence of copper(I).
Scheme 81: Oxidative trifluoromethylation of imidazoheterocycles in ionic liquid/water.
Scheme 82: A mild and fast continuous-flow trifluoromethylation of coumarins using a CuI/CF3SO2Na/TBHP system.
Scheme 83: Copper-catalyzed oxidative trifluoromethylation of various 8-aminoquinolines.
Scheme 84: PA-directed copper-catalyzed trifluoromethylation of anilines.
Scheme 85: Trifluoromethylation of potassium vinyltrifluoroborates catalyzed by Fe(II).
Scheme 86: Alkenyl trifluoromethylation catalyzed by Ru(phen)3Cl2 as photocatalyst.
Scheme 87: Ru-catalyzed trifluoromethylation of alkenes by Akita’s group.
Scheme 88: Ir-catalyzed Cvinyl–CF3 bond formation of α,β-unsaturated carboxylic acids.
Scheme 89: Ag(I)-catalyzed denitrative trifluoromethylation of β-nitrostyrenes.
Scheme 90: Photocatalyzed direct trifluoromethylation of aryl and heteroaryl C–H bonds.
Scheme 91: Rhenium (MTO)-catalyzed direct trifluoromethylation of aromatic substrates.
Scheme 92: Trifluoromethylation of unprotected anilines under [Ir(ppy)3] catalyst.
Scheme 93: Oxidative trifluoromethylation of imidazopyridines and imidazoheterocycles.
Scheme 94: Ruthenium-catalyzed trifluoromethylation of (hetero)arenes with trifluoroacetic anhydride.
Scheme 95: Phosphovanadomolybdic acid-catalyzed direct C–H trifluoromethylation.
Scheme 96: Picolinamide-assisted ortho-trifluoromethylation of arylamines.
Scheme 97: A nickel-catalyzed C–H trifluoromethylation of free anilines.
Scheme 98: Cu-mediated trifluoromethylation of terminal alkynes reported by Qing.
Scheme 99: Huang’s C(sp)–H trifluoromethylation using Togni’s reagent.
Scheme 100: Cu-catalyzed methods for trifluoromethylation with Umemoto’s reagent.
Scheme 101: The synthesis of alkynyl-CF3 compounds in the presence of fac-[Ir(ppy)3] under visible-light irradi...
Scheme 102: Pd-catalyzed Heck reaction reported by Reutrakul.
Scheme 103: Difluoromethylation of enamides and ene-carbamates.
Scheme 104: Difluoromethylation of α,β-unsaturated carboxylic acids.
Scheme 105: Copper-catalyzed direct C(sp2)–H difluoroacetylation reported by Pannecoucke and co-workers.
Scheme 106: Difluoroalkylation of aldehyde-derived hydrazones with functionalized difluoromethyl bromides.
Scheme 107: Photoredox-catalyzed C–H difluoroalkylation of aldehyde-derived hydrazones.
Scheme 108: Synergistic ruthenium(II)-catalyzed C–H difluoromethylation reported by Ackermann.
Scheme 109: Visible-light photocatalytic decarboxylation of α,β-unsaturated carboxylic acids.
Scheme 110: Synthesis of difluorinated ketones via S-alkyl dithiocarbamates obtained from acyl chlorides and po...
Scheme 111: Synthesis of aryl and heteroaryl difluoromethylated phosphonates.
Scheme 112: Difluoroalkylation of secondary propargyl sulfonates using Cu as the catalyst.
Scheme 113: Ru(II)-mediated para-selective difluoromethylation of anilides and their derivatives.
Scheme 114: Bulky diamine ligand promoted cross-coupling of difluoroalkyl bromides.
Scheme 115: Copper-catalyzed C3–H difluoroacetylation of quinoxalinones.
Scheme 116: Copper(I) chloride-catalyzed trifluoromethylthiolation of enamines, indoles and β-ketoesters.
Scheme 117: Copper-boxmi-catalyzed asymmetric trifluoromethylthiolation of β-ketoesters.
Scheme 118: Direct Cu-catalyzed trifluoromethylthiolation of boronic acids and alkynes.
Scheme 119: Cu-catalyzed synthesis of α-trifluoromethylthio-substituted ketones.
Scheme 120: Trifluoromethylthiolation reactions promoted by diazotriflone and copper.
Scheme 121: Halide activation of N-(trifluoromethylthio)phthalimide.
Scheme 122: The visible light-promoted trifluoromethylthiolation reported by Glorius.
Scheme 123: Synthesis of α-trifluoromethylthioesters via Goossen’s approach.
Scheme 124: Photoinduced trifluoromethylthiolation of diazonium salts.
Scheme 125: Ag-mediated trifluoromethoxylation of aryl stannanes and arylboronic acids.
Scheme 126: Catalytic (hetero)aryl C–H trifluoromethoxylation under visible light.
Scheme 127: Photoinduced C–H-bond trifluromethoxylation of (hetero)arenes.
Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage
- Gagandeep Kour Reen,
- Ashok Kumar and
- Pratibha Sharma
Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165
- , recyclable catalyst in the N-arylation of indoles [45][46]. Copper catalysts have shown exceptional enantioselectivity for reactions such as hydrosilylation, hydroboration, and heterogeneous as well as homogeneous hydrogenation [47][48][49]. Also, the copper salts found used as oxidants in a number of
Graphical Abstract
Figure 1: Various drugs having IP nucleus.
Figure 2: Participation percentage of various TMs for the syntheses of IPs.
Scheme 1: CuI–NaHSO4·SiO2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 2: Experimental examination of reaction conditions.
Scheme 3: One-pot tandem reaction for the synthesis of 2-haloimidazopyridines.
Scheme 4: Mechanistic scheme for the synthesis of 2-haloimidazopyridine.
Scheme 5: Copper-MOF-catalyzed three-component reaction (3-CR) for imidazo[1,2-a]pyridines.
Scheme 6: Mechanism for copper-MOF-driven synthesis.
Scheme 7: Heterogeneous synthesis via titania-supported CuCl2.
Scheme 8: Mechanism involving oxidative C–H functionalization.
Scheme 9: Heterogeneous synthesis of IPs.
Scheme 10: One-pot regiospecific synthesis of imidazo[1,2-a]pyridines.
Scheme 11: Vinyl azide as an unprecedented substrate for imidazo[1,2-a]pyridines.
Scheme 12: Radical pathway.
Scheme 13: Cu(I)-catalyzed transannulation approach for imidazo[1,5-a]pyridines.
Scheme 14: Plausible radical pathway for the synthesis of imidazo[1,5-a]pyridines.
Scheme 15: A solvent-free domino reaction for imidazo[1,2-a]pyridines.
Scheme 16: Cu-NPs-mediated synthesis of imidazo[1,2-a]pyridines.
Scheme 17: CuI-catalyzed synthesis of isoxazolylimidazo[1,2-a]pyridines.
Scheme 18: Functionalization of 4-bromo derivative via Sonogashira coupling reaction.
Scheme 19: A plausible reaction pathway.
Scheme 20: Cu(I)-catalyzed intramolecular oxidative C–H amidation reaction.
Scheme 21: One-pot synthetic reaction for imidazo[1,2-a]pyridine.
Scheme 22: Plausible reaction mechanism.
Scheme 23: Cu(OAc)2-promoted synthesis of imidazo[1,2-a]pyridines.
Scheme 24: Mechanism for aminomethylation/cycloisomerization of propiolates with imines.
Scheme 25: Three-component synthesis of imidazo[1,2-a]pyridines.
Figure 3: Scope of pyridin-2(1H)-ones and acetophenones.
Scheme 26: CuO NPS-promoted A3 coupling reaction.
Scheme 27: Cu(II)-catalyzed C–N bond formation reaction.
Scheme 28: Mechanism involving Chan–Lam/Ullmann coupling.
Scheme 29: Synthesis of formyl-substituted imidazo[1,2-a]pyridines.
Scheme 30: A tandem sp3 C–H amination reaction.
Scheme 31: Probable mechanistic approach.
Scheme 32: Dual catalytic system for imidazo[1,2-a]pyridines.
Scheme 33: Tentative mechanism.
Scheme 34: CuO/CuAl2O4/ᴅ-glucose-promoted 3-CCR.
Scheme 35: A tandem CuOx/OMS-2-based synthetic strategy.
Figure 4: Biomimetic catalytic oxidation in the presence of electron-transfer mediators (ETMs).
Scheme 36: Control experiment.
Scheme 37: Copper-catalyzed C(sp3)–H aminatin reaction.
Scheme 38: Reaction of secondary amines.
Scheme 39: Probable mechanistic pathway.
Scheme 40: Coupling reaction of α-azidoketones.
Scheme 41: Probable pathway.
Scheme 42: Probable mechanism with free energy calculations.
Scheme 43: MCR for cyanated IP synthesis.
Scheme 44: Substrate scope for the reaction.
Scheme 45: Reaction mechanism.
Scheme 46: Probable mechanistic pathway for Cu/ZnAl2O4-catalyzed reaction.
Scheme 47: Copper-catalyzed double oxidative C–H amination reaction.
Scheme 48: Application towards different coupling reactions.
Scheme 49: Reaction mechanism.
Scheme 50: Condensation–cyclization approach for the synthesis of 1,3-diarylated imidazo[1,5-a]pyridines.
Scheme 51: Optimized reaction conditions.
Scheme 52: One-pot 2-CR.
Scheme 53: One-pot 3-CR without the isolation of chalcone.
Scheme 54: Copper–Pybox-catalyzed cyclization reaction.
Scheme 55: Mechanistic pathway catalyzed by Cu–Pybox complex.
Scheme 56: Cu(II)-promoted C(sp3)-H amination reaction.
Scheme 57: Wider substrate applicability for the reaction.
Scheme 58: Plausible reaction mechanism.
Scheme 59: CuI assisted C–N cross-coupling reaction.
Scheme 60: Probable reaction mechanism involving sp3 C–H amination.
Scheme 61: One-pot MCR-catalyzed by CoFe2O4/CNT-Cu.
Scheme 62: Mechanistic pathway.
Scheme 63: Synthetic scheme for 3-nitroimidazo[1,2-a]pyridines.
Scheme 64: Plausible mechanism for CuBr-catalyzed reaction.
Scheme 65: Regioselective synthesis of halo-substituted imidazo[1,2-a]pyridines.
Scheme 66: Synthesis of 2-phenylimidazo[1,2-a]pyridines.
Scheme 67: Synthesis of diarylated compounds.
Scheme 68: CuBr2-mediated one-pot two-component oxidative coupling reaction.
Scheme 69: Decarboxylative cyclization route to synthesize 1,3-diarylimidazo[1,5-a]pyridines.
Scheme 70: Mechanistic pathway.
Scheme 71: C–H functionalization reaction of enamines to produce diversified heterocycles.
Scheme 72: A plausible mechanism.
Scheme 73: CuI-promoted aerobic oxidative cyclization reaction of ketoxime acetates and pyridines.
Scheme 74: CuI-catalyzed pathway for the formation of imidazo[1,2-a]pyridine.
Scheme 75: Mechanistic pathway.
Scheme 76: Mechanistic rationale for the synthesis of products.
Scheme 77: Copper-catalyzed synthesis of vinyloxy-IP.
Scheme 78: Regioselective product formation with propiolates.
Scheme 79: Proposed mechanism for vinyloxy-IP formation.
Scheme 80: Regioselective synthesis of 3-hetero-substituted imidazo[1,2-a]pyridines with different reaction su...
Scheme 81: Mechanistic pathway.
Scheme 82: CuI-mediated synthesis of 3-formylimidazo[1,2-a]pyridines.
Scheme 83: Radical pathway for 3-formylated IP synthesis.
Scheme 84: Pd-catalyzed urea-cyclization reaction for IPs.
Scheme 85: Pd-catalyzed one-pot-tandem amination and intramolecular amidation reaction.
Figure 5: Scope of aniline nucleophiles.
Scheme 86: Pd–Cu-catalyzed Sonogashira coupling reaction.
Scheme 87: One-pot amide coupling reaction for the synthesis of imidazo[4,5-b]pyridines.
Scheme 88: Urea cyclization reaction for the synthesis of two series of pyridines.
Scheme 89: Amidation reaction for the synthesis of imidazo[4,5-b]pyridines.
Figure 6: Amide scope.
Scheme 90: Pd NPs-catalyzed 3-component reaction for the synthesis of 2,3-diarylated IPs.
Scheme 91: Plausible mechanistic pathway for Pd NPs-catalyzed MCR.
Scheme 92: Synthesis of chromenoannulated imidazo[1,2-a]pyridines.
Scheme 93: Mechanism for the synthesis of chromeno-annulated IPs.
Scheme 94: Zinc oxide NRs-catalyzed synthesis of imidazo[1,2-a]azines/diazines.
Scheme 95: Zinc oxide-catalyzed isocyanide based GBB reaction.
Scheme 96: Reaction pathway for ZnO-catalyzed GBB reaction.
Scheme 97: Mechanistic pathway.
Scheme 98: ZnO NRs-catalyzed MCR for the synthesis of imidazo[1,2-a]azines.
Scheme 99: Ugi type GBB three-component reaction.
Scheme 100: Magnetic NPs-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 101: Regioselective synthesis of 2-alkoxyimidazo[1,2-a]pyridines catalyzed by Fe-SBA-15.
Scheme 102: Plausible mechanistic pathway for the synthesis of 2-alkoxyimidazopyridine.
Scheme 103: Iron-catalyzed synthetic approach.
Scheme 104: Iron-catalyzed aminooxygenation reaction.
Scheme 105: Mechanistic pathway.
Scheme 106: Rh(III)-catalyzed double C–H activation of 2-substituted imidazoles and alkynes.
Scheme 107: Plausible reaction mechanism.
Scheme 108: Rh(III)-catalyzed non-aromatic C(sp2)–H bond activation–functionalization for the synthesis of imid...
Scheme 109: Reactivity and selectivity of different substrates.
Scheme 110: Rh-catalyzed direct C–H alkynylation by Li et al.
Scheme 111: Suggested radical mechanism.
Scheme 112: Scandium(III)triflate-catalyzed one-pot reaction and its mechanism for the synthesis of benzimidazo...
Scheme 113: RuCl3-assisted Ugi-type Groebke–Blackburn condensation reaction.
Scheme 114: C-3 aroylation via Ru-catalyzed two-component reaction.
Scheme 115: Regioselective synthetic mechanism.
Scheme 116: La(III)-catalyzed one-pot GBB reaction.
Scheme 117: Mechanistic approach for the synthesis of imidazo[1,2-a]pyridines.
Scheme 118: Synthesis of imidazo[1,2-a]pyridine using LaMnO3 NPs under neat conditions.
Scheme 119: Mechanistic approach.
Scheme 120: One-pot 3-CR for regioselective synthesis of 2-alkoxy-3-arylimidazo[1,2-a]pyridines.
Scheme 121: Formation of two possible products under optimization of the catalysts.
Scheme 122: Mechanistic strategy for NiFe2O4-catalyzed reaction.
Scheme 123: Two-component reaction for synthesizing imidazodipyridiniums.
Scheme 124: Mechanistic scheme for the synthesis of imidazodipyridiniums.
Scheme 125: CuI-catalyzed arylation of imidazo[1,2-a]pyridines.
Scheme 126: Mechanism for arylation reaction.
Scheme 127: Cupric acetate-catalyzed double carbonylation approach.
Scheme 128: Radical mechanism for double carbonylation of IP.
Scheme 129: C–S bond formation reaction catalyzed by cupric acetate.
Scheme 130: Cupric acetate-catalyzed C-3 formylation approach.
Scheme 131: Control experiments for signifying the role of DMSO and oxygen.
Scheme 132: Mechanism pathway.
Scheme 133: Copper bromide-catalyzed CDC reaction.
Scheme 134: Extension of the substrate scope.
Scheme 135: Plausible radical pathway.
Scheme 136: Transannulation reaction for the synthesis of imidazo[1,5-a]pyridines.
Scheme 137: Plausible reaction pathway for denitrogenative transannulation.
Scheme 138: Cupric acetate-catalyzed C-3 carbonylation reaction.
Scheme 139: Plausible mechanism for regioselective C-3 carbonylation.
Scheme 140: Alkynylation reaction at C-2 of 3H-imidazo[4,5-b]pyridines.
Scheme 141: Two-way mechanism for C-2 alkynylation of 3H-imidazo[4,5-b]pyridines.
Scheme 142: Palladium-catalyzed SCCR approach.
Scheme 143: Palladium-catalyzed Suzuki coupling reaction.
Scheme 144: Reaction mechanism.
Scheme 145: A phosphine free palladium-catalyzed synthesis of C-3 arylated imidazopyridines.
Scheme 146: Palladium-mediated Buchwald–Hartwig cross-coupling reaction.
Figure 7: Structure of the ligands optimized.
Scheme 147: Palladium acetate-catalyzed direct arylation of imidazo[1,2-a]pyridines.
Scheme 148: Palladium acetate-catalyzed mechanistic pathway.
Scheme 149: Palladium acetate-catalyzed regioselective arylation reported by Liu and Zhan.
Scheme 150: Mechanism for selective C-3 arylation of IP.
Scheme 151: Pd(II)-catalyzed alkenylation reaction with styrenes.
Scheme 152: Pd(II)-catalyzed alkenylation reaction with acrylates.
Scheme 153: A two way mechanism.
Scheme 154: Double C–H activation reaction catalyzed by Pd(OAc)2.
Scheme 155: Probable mechanism.
Scheme 156: Palladium-catalyzed decarboxylative coupling.
Scheme 157: Mechanistic cycle for decarboxylative arylation reaction.
Scheme 158: Ligand-free approach for arylation of imidazo[1,2-a]pyridine-3-carboxylic acids.
Scheme 159: Mechanism for ligandless arylation reaction.
Scheme 160: NHC-Pd(II) complex assisted arylation reaction.
Scheme 161: C-3 arylation of imidazo[1,2-a]pyridines with aryl bromides catalyzed by Pd(OAc)2.
Scheme 162: Pd(II)-catalyzed C-3 arylations with aryl tosylates and mesylates.
Scheme 163: CDC reaction for the synthesis of imidazo[1,2-a]pyridines.
Scheme 164: Plausible reaction mechanism for Pd(OAc)2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 165: Pd-catalyzed C–H amination reaction.
Scheme 166: Mechanism for C–H amination reaction.
Scheme 167: One-pot synthesis for 3,6-di- or 2,3,6-tri(hetero)arylimidazo[1,2-a]pyridines.
Scheme 168: C–H/C–H cross-coupling reaction of IPs and azoles catalyzed by Pd(II).
Scheme 169: Mechanistic cycle.
Scheme 170: Rh-catalyzed C–H arylation reaction.
Scheme 171: Mechanistic pathway for C–H arylation of imidazo[1,2-a]pyridine.
Scheme 172: Rh(III)-catalyzed double C–H activation of 2-phenylimidazo[1,2-a]pyridines and alkynes.
Scheme 173: Rh(III)-catalyzed mechanistic pathway.
Scheme 174: Rh(III)-mediated oxidative coupling reaction.
Scheme 175: Reactions showing functionalization of the product obtained by the group of Kotla.
Scheme 176: Mechanism for Rh(III)-catalyzed oxidative coupling reaction.
Scheme 177: Rh(III)-catalyzed C–H activation reaction.
Scheme 178: Mechanistic cycle.
Scheme 179: Annulation reactions of 2-arylimidazo[1,2-a]pyridines and alkynes.
Scheme 180: Two-way reaction mechanism for annulations reaction.
Scheme 181: [RuCl2(p-cymene)]2-catalyzed C–C bond formation reaction.
Scheme 182: Reported reaction mechanism.
Scheme 183: Fe(III) catalyzed C-3 formylation approach.
Scheme 184: SET mechanism-catalyzed by Fe(III).
Scheme 185: Ni(dpp)Cl2-catalyzed KTC coupling.
Scheme 186: Pd-catalyzed SM coupling.
Scheme 187: Vanadium-catalyzed coupling of IP and NMO.
Scheme 188: Mechanistic cycle.
Scheme 189: Selective C3/C5–H bond functionalizations by mono and bimetallic systems.
Scheme 190: rGO-Ni@Pd-catalyzed C–H bond arylation of imidazo[1,2-a]pyridine.
Scheme 191: Mechanistic pathway for heterogeneously catalyzed arylation reaction.
Scheme 192: Zinc triflate-catalyzed coupling reaction of substituted propargyl alcohols.
A heteroditopic macrocycle as organocatalytic nanoreactor for pyrroloacridinone synthesis in water
- Piyali Sarkar,
- Sayan Sarkar and
- Pradyut Ghosh
Beilstein J. Org. Chem. 2019, 15, 1505–1514, doi:10.3762/bjoc.15.152
- materials in water within 8 h. Following this green methodology, we successfully synthesized 4,5-dihydropyrroloacridinones and fully aromatized pyrrolo analogues in the eco-friendly solvent water with BATA-MC as a recyclable catalyst. Moreover, some of the synthesized acridines may find medicinal
Graphical Abstract
Figure 1: Bis-amido-tris-amine macrocycle BATA-MC.
Figure 2: (a) Number distribution plot with particle size in DLS, (b) SEM image and (c) TEM image showing the...
Figure 3: Dependence of the yield of compound 4a on the reaction time using BATA-MC.
Figure 4: Yields of product 4a at different catalyst loading.
Scheme 1: BATA-MC-catalyzed synthesis of 4,5-dihydropyrrolo[2,3,4-kl]acridinones.
Scheme 2: BATA-MC-catalyzed synthesis of pyrrolo[2,3,4-kl]acridinone derivatives.
Figure 5: X-ray single crystal structure of 4d (CCDC 1898008).
Scheme 3: Probable mechanism illustrated for the synthesis of 4a using BATA-MC. For the sake of simplicity, w...
Figure 6: Representation of BATA-MC nanoreactor.
Figure 7: The reusability of the nanoreactor for the synthesis of 4a.
Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams
- Edorta Martínez de Marigorta,
- Jesús M. de Los Santos,
- Ana M. Ochoa de Retana,
- Javier Vicario and
- Francisco Palacios
Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104
- heterocycle containing five- and six-membered fused N-heterocyclic rings (Scheme 16), including the γ-lactam unit. The first synthesis of this class of compounds was reported by Pal et al. [96] with the aid of montmorillonite K10 as a recyclable catalyst in ethanol. With these environmentally friendly
Graphical Abstract
Figure 1: γ-Lactam-derived structures considered in this review.
Figure 2: Alkaloids containing an isoindolinone moiety.
Figure 3: Alkaloids containing the 2-oxindole ring system.
Figure 4: Drugs and biological active compounds containing an isoindolinone moiety.
Figure 5: Drugs and biologically active compounds bearing a 2-oxindole skeleton.
Scheme 1: Three-component reaction of benzoic acid 1, amides 2 and DMSO (3).
Scheme 2: Copper-catalysed three-component reaction of 2-iodobenzoic acids 10, alkynylcarboxylic acids 11 and...
Scheme 3: Proposed mechanism for the formation of methylene isoindolinones 13.
Scheme 4: Copper-catalysed three-component reaction of 2-iodobenzamide 17, terminal alkyne 18 and pyrrole or ...
Scheme 5: Palladium-catalysed three-component reaction of ethynylbenzamides 21, secondary amines 22 and CO (23...
Scheme 6: Proposed mechanism for the formation of methyleneisoindolinones 24.
Scheme 7: Copper-catalysed three-component reaction of formyl benzoate 29, amines 2 and alkynes 18.
Scheme 8: Copper-catalysed three-component reaction of formylbenzoate 29, amines 2 and ketones 31.
Scheme 9: Non-catalysed (A) and phase-transfer catalysed (B) three-component reactions of formylbenzoic acids ...
Scheme 10: Proposed mechanism for the formation of isoindolinones 36.
Scheme 11: Three-component reaction of formylbenzoic acid 33, amines 2 and fluorinated silyl ethers 39.
Scheme 12: Three-component Ugi reaction of 2-formylbenzoic acid (33), diamines 41 and isocyanides 42.
Scheme 13: Non-catalysed (A, B) and chiral phosphoric acid promoted (C) three-component Ugi reactions of formy...
Scheme 14: Proposed mechanism for the enantioselective formation of isoindolinones 46.
Scheme 15: Three-component reaction of benzoic acids 33 or 54, amines 2 and TMSCN (52).
Scheme 16: Several variations of the three-component reaction of formylbenzoic acids 33, amines 2 and isatoic ...
Scheme 17: Proposed mechanism for the synthesis of isoindoloquinazolinones 57.
Scheme 18: Three-component reaction of isobenzofuranone 61, amines 2 and isatoic anhydrides 56.
Scheme 19: Palladium-catalysed three-component reaction of 2-aminobenzamides 59, 2-bromobenzaldehydes 62 and C...
Scheme 20: Proposed mechanism for the palladium-catalysed synthesis of isoindoloquinazolinones 57.
Scheme 21: Four-component reaction of 2-vinylbenzoic acids 67, aryldioazonium tetrafluoroborates 68, DABCO·(SO2...
Scheme 22: Plausible mechanism for the formation of isoindolinones 71.
Scheme 23: Three-component reaction of trimethylsilylaryltriflates 77, isocyanides 42 and CO2 (78).
Scheme 24: Plausible mechanism for the three-component synthesis of phthalimides 79.
Scheme 25: Copper-catalysed three-component reaction of 2-formylbenzonitriles 85, arenes 86 and diaryliodonium...
Scheme 26: Copper-catalysed three-component reaction of 2-formylbenzonitriles 85, diaryliodonium salts 87 and ...
Scheme 27: Proposed mechanism for the formation of 2,3-diarylisoindolinones 88, 89 and 92.
Scheme 28: Palladium-catalysed three-component reaction of chloroquinolinecarbaldehydes 97 with isocyanides 42...
Scheme 29: Palladium-catalysed three-component reaction of imines 99 with CO (23) and ortho-iodoarylimines 100....
Scheme 30: Palladium-catalysed three-component reaction of amines 2 with CO (23) and aryl iodide 105.
Scheme 31: Three-component reaction of 2-ethynylanilines 109, perfluoroalkyl iodides 110 and carbon monoxide (...
Scheme 32: Ultraviolet-induced three-component reaction of N-(2-iodoaryl)acrylamides 113, DABCO·(SO2)2 (69) an...
Scheme 33: Proposed mechanism for the preparation of oxindoles 115.
Scheme 34: Three-component reaction of acrylamide 113, CO (23) and 1,4-benzodiazepine 121.
Scheme 35: Multicomponent reaction of sulfonylacrylamides 123, aryldiazonium tetrafluoroborates 68 and DABCO·(...
Scheme 36: Proposed mechanism for the preparation of oxindoles 124.
Scheme 37: Three-component reaction of N-arylpropiolamides 128, aryl iodides 129 and boronic acids 130.
Scheme 38: Proposed mechanism for the formation of diarylmethylene- and diarylallylideneoxindoles 131 and 132.
Scheme 39: Three-component reaction of cyclohexa-1,3-dione (136), amines 2 and alkyl acetylenedicarboxylates 1...
Scheme 40: Proposed mechanism for the formation of 2-oxindoles 138.
Ammonium-tagged ruthenium-based catalysts for olefin metathesis in aqueous media under ultrasound and microwave irradiation
- Łukasz Gułajski,
- Andrzej Tracz,
- Katarzyna Urbaniak,
- Stefan J. Czarnocki,
- Michał Bieniek and
- Tomasz K. Olszewski
Beilstein J. Org. Chem. 2019, 15, 160–166, doi:10.3762/bjoc.15.16
- Lipshutz and co-workers [41]. Worth mentioning are also reports of heterogenous and recyclable catalysis able to mediate metathesis in aqueous media [42][43][44][45]. Although the aforementioned examples show a significant progress in the olefin metathesis in aqueous media, some limitations such as complex
Graphical Abstract
Figure 1: Structures of the Ru-based catalysts used in this study.
An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes
- Hashem Sharghi,
- Pezhman Shiri and
- Mahdi Aberi
Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253
- [DISM][CCl3COO] (18) and [Dsim][CF3COO] (19) ILs were utilized as recyclable, efficient, and eco-benign catalysts for the three-component one-pot condensations towards a variety of 1,8-dioxodecahydroacridine derivatives 22 and 14H-dibenzo[a,j]xanthene derivatives 24 in short reaction times under solvent
Graphical Abstract
Figure 1: Different types of sulfonated materials as acid catalysts.
Scheme 1: Synthetic route of 3-methyl-1-sulfo-1H-imidazolium metal chloride ILs and their catalytic applicati...
Scheme 2: Synthetic route of 1,3-disulfo-1H-imidazolium transition metal chloride ILs and their catalytic app...
Scheme 3: Synthetic route of 1,3-disulfoimidazolium carboxylate ILs and their catalytic applications in the s...
Scheme 4: Synthetic route of [BiPy](HSO3)2Cl2 and [Dsim]HSO4 ILs and their catalytic applications for the syn...
Scheme 5: The catalytic applications of (C4(DABCO-SO3H)2·4Cl) IL for the synthesis of spiro-isatin derivative...
Scheme 6: The catalytic applications of (C4(DABCO-SO3H)2·4Cl) IL for the synthesis of bis 2-amino-4H-pyran de...
Scheme 7: The synthetic route of N,N-disulfo-1,1,3,3-tetramethylguanidinium carboxylate ILs and their catalyt...
Scheme 8: The catalytic application of 1-methyl-3-sulfo-1H-imidazolium tetrachloroferrate IL in the synthesis...
Scheme 9: The synthetic route of 3-sulfo-1H-imidazolopyrimidinium hydrogen sulfate IL and its catalytic appli...
Scheme 10: The results for the synthesis of bis(indolyl)methanes and di(bis(indolyl)methyl)benzenes in the pre...
Scheme 11: The catalytic applications of 1-(1-sulfoalkyl)-3-methylimidazolium chloride acidic ILs for the hydr...
Scheme 12: The synthetic route of immobilized 1,4-diazabicyclo[2.2.2]octanesulfonic acid chloride on SiO2 and ...
Scheme 13: The catalytic application of a silica-bonded sulfoimidazolium chloride for the synthesis of 12-aryl...
Scheme 14: The synthetic route of the SBA-15-Ph-SO3H and its catalytic applications for the synthesis of 2H-in...
Scheme 15: The synthetic route for heteropolyanion-based ionic liquids immobilized on mesoporous silica SBA-15...
Scheme 16: Some mechanism aspects of SSA catalyst for the protection of amine derivatives.
Scheme 17: The synthetic route for MWCNT-SO3H and its catalytic application for the synthesis of N-substituted...
Scheme 18: The sulfonic acid-functionalized polymers (P-SO3H) covalently grafted on multi-walled carbon nanotu...
Scheme 19: The transesterification reaction in the presence of S-MWCNTs.
Scheme 20: The synthetic route for the new hypercrosslinked supermicroporous polymer via the Friedel–Crafts al...
Scheme 21: The synthetic route for a new microporous copolymer via the Friedel–Crafts alkylation reaction of t...
Scheme 22: The synthetic route for sulfonated polynaphthalene and its catalytic application for the amidoalkyl...
Scheme 23: The synthetic route of the acidic carbon material and its catalytic application in the etherificatio...
Scheme 24: The synthetic route of the acidic carbon materials and their catalytic applications for the esterif...
Scheme 25: The sulfonated MWCNTs.
Scheme 26: The sulfonated nanoscaled diamond powder for the dehydration of D-xylose into furfural.
Scheme 27: The synthetic route and catalytic application of the GR-SO3H.
Heterogeneous acidic catalysts for the tetrahydropyranylation of alcohols and phenols in green ethereal solvents
- Ugo Azzena,
- Massimo Carraro,
- Gloria Modugno,
- Luisa Pisano and
- Luigi Urtis
Beilstein J. Org. Chem. 2018, 14, 1655–1659, doi:10.3762/bjoc.14.141
- into the corresponding tetrahydropyranyl ethers in cyclopentyl methyl ether or 2-methyltetrahydrofuran employing NH4HSO4 supported on SiO2 as a recyclable acidic catalyst. Easy work up of the reaction mixtures and the versatility of the solvents allowed further conversion of the reaction products under
- , heterogeneous and recyclable catalysts to promote THP ethers synthesis [2][8][9][10][11][12][13][14], to the best of our knowledge no attention was dedicated to their employment in low impact solvents. From this point of view, it is worth noting that although ethers are the solvents of choice for reactions
Graphical Abstract
Scheme 1: Synthesis of THP ether 3a.
Scheme 2: Synthesis of THP ethers 3b–l in the presence of NH4HSO4@SiO2. All reactions were run at rt, in the ...
Scheme 3: Deprotection of THP ether 3i.
Scheme 4: One-pot synthesis of 3-[4-(tetrahydro-2H-pyran-2-yl)oxymethylphenyl]-3-pentanol (4fa).
Scheme 5: One-pot synthesis of 4-(tetrahydro-2H-pyran-2-yloxymethyl)benzyl alcohol (4fb).
Recyclable hypervalent-iodine-mediated solid-phase peptide synthesis and cyclic peptide synthesis
- Dan Liu,
- Ya-Li Guo,
- Jin Qu and
- Chi Zhang
Beilstein J. Org. Chem. 2018, 14, 1112–1119, doi:10.3762/bjoc.14.97
- worth noting that FPID can be readily regenerated after the peptide coupling reaction. Keywords: cyclic peptide; FPID; hypervalent iodine(III) reagent; recyclable; solid-phase peptide synthesis (SPPS); Introduction The amide bond is one of the most fundamental functional groups in organic chemistry
Graphical Abstract
Figure 1: Iodosodilactone and FPID.
Scheme 1: Proposed mechanism for FPID-mediated amide bond formation.
Scheme 2: Solid-phase peptide synthesis mediated by FPID/(4-MeOC6H4)3P. Conditions: The resin loading for 2-C...
Scheme 3: The regeneration of FPID after SPPS.
Figure 2: Structure of pseudostellarin D.
Scheme 4: Synthetic strategies of pseudostellarin D.
Scheme 5: Preparation of the precursor of pseudostellarin D.
Nanoreactors for green catalysis
- M. Teresa De Martino,
- Loai K. E. A. Abdelmohsen,
- Floris P. J. T. Rutjes and
- Jan C. M. van Hest
Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61
- undesired products, providing a platform for aqueous ROP [21]. As shown in this section, polymersomes have been applied as a platform towards greener reactions [22][88], either by allowing reactions to be performed in water [21][83] or by providing a recyclable catalytic system [80]. As they contain both
Graphical Abstract
Figure 1: Assembly of catalyst-functionalized amphiphilic block copolymers into polymer micelles and vesicles...
Scheme 1: C–N bond formation under micellar catalyst conditions, no organic solvent involved. Adapted from re...
Scheme 2: Suzuki−Miyaura couplings with, or without, ppm Pd. Conditions: ArI 0.5 mmol 3a, Ar’B(OH)2 (0.75–1.0...
Figure 2: PQS (4a), PQS attached proline catalyst 4b. Adapted from reference [26]. Copyright 2012 American Chemic...
Figure 3: 3a) Schematic representation of a Pickering emulsion with the enzyme in the water phase (i), or wit...
Scheme 3: Cascade reaction with GOx and Myo. Adapted from reference [82].
Figure 4: Cross-linked polymersomes with Cu(OTf)2 catalyst. Reprinted with permission from [15].
Figure 5: Schematic representation of enzymatic polymerization in polymersomes. (A) CALB in the aqueous compa...
Figure 6: Representation of DSN-G0. Reprinted with permission from [100].
Figure 7: The multivalent esterase dendrimer 5 catalyzes the hydrolysis of 8-acyloxypyrene 1,3,6-trisulfonate...
Figure 8: Conversion of 4-NP in five successive cycles of reduction, catalyzed by Au@citrate, Au@PEG and Au@P...
Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry
- Katharina Hiebler,
- Georg J. Lichtenegger,
- Manuel C. Maier,
- Eun Sung Park,
- Renie Gonzales-Groom,
- Bernard P. Binks and
- Heidrun Gruber-Woelfler
Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52
- , concerning the synthesis of pharmaceuticals, tedious purification steps need to be performed in order to remove residual metals. Considering these drawbacks of homogeneous catalysis, easily recoverable and recyclable heterogeneous Pd catalysts are much more attractive with respect to ecological and
Graphical Abstract
Figure 1: Targeted integrated multistep synthesis of valsartan (1) and sacubitril (2).
Scheme 1: Suzuki–Miyaura coupling of phenylboronic acid 3 with various bromoarenes 4a–e (a: R1 = H, R2 = CH3; ...
Figure 2: Particle size distribution of Ce0.495Sn0.495Pd0.01O2–δ after size reduction via milling and separat...
Figure 3: Optical microscope images of fresh aqueous dispersions, 0.05 wt %, of (a) Ce0.495Sn0.495Pd0.01O2–δ ...
Figure 4: Photos of vessels containing cyclohexane-in-water emulsions stabilised by particles of Ce0.495Sn0.4...
Figure 5: Optical microscopy images of cyclohexane-in-water emulsions of Figure 4 after one month for particle concen...
Figure 6: (top) Mean emulsion droplet diameter after 30 min as a function of particle concentration for syste...
Figure 7: Mean particle diameter in aqueous dispersions as a function of Ce0.495Sn0.495Pd0.01O2–δ concentrati...
Figure 8: Variation of the zeta potential and pH value of aqueous dispersions of Ce0.495Sn0.495Pd0.01O2–δ par...
Figure 9: (a) Appearance of octane-in-water emulsions with time at 0.05 wt % of Ce0.495Sn0.495Pd0.01O2–δ (lef...
Figure 10: (a) Variation of droplet diameter with particle concentration for octane-in-water emulsions stabili...
Figure 11: (a) Variation of droplet diameter with particle concentration for toluene-in-water emulsions stabil...
Mannich base-connected syntheses mediated by ortho-quinone methides
- Petra Barta,
- Ferenc Fülöp and
- István Szatmári
Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43
- time and energy are saved. Recently the applicability of nanocatalysts in these reactions has been of interest since nanocatalysts, in general, are stable and recyclable and they exhibit higher activity than conventional catalysts. A few notable examples are worth mentioning here. Aluminatesulfonic
Graphical Abstract
Scheme 1: Formation of amidoalkylnaphthols 4 via o-QM intermediate 3.
Scheme 2: Asymmetric syntheses of triarylmethanes starting from diarylmethylamines.
Scheme 3: Proposed mechanism for the formation of 2,2-dialkyl-3-dialkylamino-2,3-dihydro-1H-naphtho[2,1-b]pyr...
Scheme 4: Cycloadditions of isoflavonoid-derived o-QMs and various dienophiles.
Scheme 5: [4 + 2] Cycloaddition reactions between aminonaphthols and cyclic amines.
Scheme 6: Brønsted acid-catalysed reaction between aza-o-QMs and 2- or 3-substituted indoles.
Scheme 7: Formation of 3-(α,α-diarylmethyl)indoles 52 in different synthetic pathways.
Scheme 8: Alkylation of o-QMs with N-, O- or S-nucleophiles.
Scheme 9: Formation of DNA linkers and o-QM mediated polymers.
Progress in copper-catalyzed trifluoromethylation
- Guan-bao Li,
- Chao Zhang,
- Chun Song and
- Yu-dao Ma
Beilstein J. Org. Chem. 2018, 14, 155–181, doi:10.3762/bjoc.14.11
- imidazoheterocycles and meet the guiding principles of green chemistry, this reaction was conducted in a recyclable mixed medium of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) and water. In the presence of catalytic amounts of cupric acetate and TBHP, various substrates, such as 6-arylimidazo[2,1-b
Graphical Abstract
Figure 1: Selected examples of pharmaceutical and agrochemical compounds containing the trifluoromethyl group....
Scheme 1: Introduction of a diamine into copper-catalyzed trifluoromethylation of aryl iodides.
Scheme 2: Addition of a Lewis acid into copper-catalyzed trifluoromethylation of aryl iodides and the propose...
Scheme 3: Trifluoromethylation of heteroaromatic compounds using S-(trifluoromethyl)diphenylsulfonium salts a...
Scheme 4: The preparation of a new trifluoromethylation reagent and its application in trifluoromethylation o...
Scheme 5: Trifluoromethylation of aryl iodides using CF3CO2Na as a trifluoromethyl source.
Scheme 6: Trifluoromethylation of aryl iodides using MTFA as a trifluoromethyl source.
Scheme 7: Trifluoromethylation of aryl iodides using CF3CO2K as a trifluoromethyl source.
Scheme 8: Trifluoromethylation of aryl iodides and heteroaryl bromides using [Cu(phen)(O2CCF3)] as a trifluor...
Scheme 9: Trifluoromethylation of aryl iodides with DFPB and the proposed mechanism.
Scheme 10: Trifluoromethylation of aryl iodides using TCDA as a trifluoromethyl source. Reaction conditions: [...
Scheme 11: The mechanism of trifluoromethylation using Cu(II)(O2CCF2SO2F)2 as a trifluoromethyl source.
Scheme 12: Trifluoromethylation of benzyl bromide reported by Shibata’s group.
Scheme 13: Trifluoromethylation of allylic halides and propargylic halides reported by the group of Nishibayas...
Scheme 14: Trifluoromethylation of propargylic halides reported by the group of Nishibayashi.
Scheme 15: Trifluoromethylation of alkyl halides reported by Nishibayashi’s group.
Scheme 16: Trifluoromethylation of pinacol esters reported by the group of Gooßen.
Scheme 17: Trifluoromethylation of primary and secondary alkylboronic acids reported by the group of Fu.
Scheme 18: Trifluoromethylation of boronic acid derivatives reported by the group of Liu.
Scheme 19: Trifluoromethylation of organotrifluoroborates reported by the group of Huang.
Scheme 20: Trifluoromethylation of aryl- and vinylboronic acids reported by the group of Shibata.
Scheme 21: Trifluoromethylation of arylboronic acids via the merger of photoredox and Cu catalysis.
Scheme 22: Trifluoromethylation of arylboronic acids reported by Sanford’s group. Isolated yield. aYields dete...
Scheme 23: Trifluoromethylation of arylboronic acids and vinylboronic acids reported by the group of Beller. Y...
Scheme 24: Copper-mediated Sandmeyer type trifluoromethylation using Umemoto’s reagent as a trifluoromethylati...
Scheme 25: Copper-mediated Sandmeyer type trifluoromethylation using TMSCF3 as a trifluoromethylation reagent ...
Scheme 26: One-pot Sandmeyer trifluoromethylation reported by the group of Gooßen.
Scheme 27: Copper-catalyzed trifluoromethylation of arenediazonium salts in aqueous media.
Scheme 28: Copper-mediated Sandmeyer trifluoromethylation using Langlois’ reagent as a trifluoromethyl source ...
Scheme 29: Trifluoromethylation of terminal alkenes reported by the group of Liu.
Scheme 30: Trifluoromethylation of terminal alkenes reported by the group of Wang.
Scheme 31: Trifluoromethylation of tetrahydroisoquinoline derivatives reported by Li and the proposed mechanis...
Scheme 32: Trifluoromethylation of phenol derivatives reported by the group of Hamashima.
Scheme 33: Trifluoromethylation of hydrazones reported by the group of Baudoin and the proposed mechanism.
Scheme 34: Trifluoromethylation of benzamides reported by the group of Tan.
Scheme 35: Trifluoromethylation of heteroarenes and electron-deficient arenes reported by the group of Qing an...
Scheme 36: Trifluoromethylation of N-aryl acrylamides using CF3SO2Na as a trifluoromethyl source.
Scheme 37: Trifluoromethylation of aryl(heteroaryl)enol acetates using CF3SO2Na as the source of CF3 and the p...
Scheme 38: Trifluoromethylation of imidazoheterocycles using CF3SO2Na as a trifluoromethyl source and the prop...
Scheme 39: Copper-mediated trifluoromethylation of terminal alkynes using TMSCF3 as a trifluoromethyl source a...
Scheme 40: Improved copper-mediated trifluoromethylation of terminal alkynes reported by the group of Qing.
Scheme 41: Copper-catalyzed trifluoromethylation of terminal alkynes reported by the group of Qing.
Scheme 42: Copper-catalyzed trifluoromethylation of terminal alkynes using Togni’s reagent and the proposed me...
Scheme 43: Copper-catalyzed trifluoromethylation of terminal alkynes using Umemoto’s reagent reported by the g...
Scheme 44: Copper-catalyzed trifluoromethylation of 3-arylprop-1-ynes reported by Xiao and Lin and the propose...
CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF3SO2Cl
- Hélène Chachignon,
- Hélène Guyon and
- Dominique Cahard
Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273
- -free and recyclable. A variety of heteroarenes, like pyrroles, oxazoles, furanes, thiophenes, indoles and pyrazines were successfully converted into the corresponding trifluoromethylated products in moderate to good yields (Scheme 27). Remarkably, a side chlorination reaction was observed during the
Graphical Abstract
Scheme 1: Trifluoromethylation of silyl enol ethers.
Scheme 2: Continuous flow trifluoromethylation of ketones under photoredox catalysis.
Scheme 3: Trifluoromethylation of enol acetates.
Scheme 4: Photoredox-catalysed tandem trifluoromethylation/cyclisation of N-arylacrylamides: a route to trifl...
Scheme 5: Tandem trifluoromethylation/cyclisation of N-arylacrylamides using BiOBr nanosheets catalysis.
Scheme 6: Photoredox-catalysed trifluoromethylation/desulfonylation/cyclisation of N-tosyl acrylamides (bpy: ...
Scheme 7: Photoredox-catalysed trifluoromethylation/aryl migration/desulfonylation of N-aryl-N-tosylacrylamid...
Scheme 8: Proposed mechanism for the trifluoromethylation/aryl migration/desulfonylation (/cyclisation) of N-...
Scheme 9: Photoredox-catalysed trifluoromethylation/cyclisation of N-methacryloyl-N-methylbenzamide derivativ...
Scheme 10: Photoredox-catalysed trifluoromethylation/cyclisation of N-methylacryloyl-N-methylbenzamide derivat...
Scheme 11: Photoredox-catalysed trifluoromethylation/dearomatising spirocyclisation of a N-benzylacrylamide de...
Scheme 12: Photoredox-catalysed trifluoromethylation/cyclisation of an unactivated alkene.
Scheme 13: Asymmetric radical aminotrifluoromethylation of N-alkenylurea derivatives using a dual CuBr/chiral ...
Scheme 14: Aminotrifluoromethylation of an N-alkenylurea derivative using a dual CuBr/phosphoric acid catalyti...
Scheme 15: 1,2-Formyl- and 1,2-cyanotrifluoromethylation of alkenes under photoredox catalysis.
Scheme 16: First simultaneous introduction of the CF3 moiety and a Cl atom onto alkenes.
Scheme 17: Chlorotrifluoromethylaltion of terminal, 1,1- and 1,2-substituted alkenes.
Scheme 18: Chorotrifluoromethylation of electron-deficient alkenes (DCE = dichloroethane).
Scheme 19: Cascade trifluoromethylation/cyclisation/chlorination of N-allyl-N-(benzyloxy)methacrylamide.
Scheme 20: Cascade trifluoromethylation/cyclisation (/chlorination) of diethyl 2-allyl-2-(3-methylbut-2-en-1-y...
Scheme 21: Trifluoromethylchlorosulfonylation of allylbenzene derivatives and aliphatic alkenes.
Scheme 22: Access to β-hydroxysulfones from CF3-containing sulfonyl chlorides through a photocatalytic sequenc...
Scheme 23: Cascade trifluoromethylchlorosulfonylation/cyclisation reaction of alkenols: a route to trifluorome...
Scheme 24: First direct C–H trifluoromethylation of arenes and proposed mechanism.
Scheme 25: Direct C–H trifluoromethylation of five- and six-membered (hetero)arenes under photoredox catalysis....
Scheme 26: Alternative pathway for the C–H trifluoromethylation of (hetero)arenes under photoredox catalysis.
Scheme 27: Direct C–H trifluoromethylation of five- and six-membered ring (hetero)arenes using heterogeneous c...
Scheme 28: Trifluoromethylation of terminal olefins.
Scheme 29: Trifluoromethylation of enamides.
Scheme 30: (E)-Selective trifluoromethylation of β-nitroalkenes under photoredox catalysis.
Scheme 31: Photoredox-catalysed trifluoromethylation/cyclisation of an o-azidoarylalkynes.
Scheme 32: Regio- and stereoselective chlorotrifluoromethylation of alkynes.
Scheme 33: PMe3-mediated trifluoromethylsulfenylation by in situ generation of CF3SCl.
Scheme 34: (EtO)2P(O)H-mediated trifluoromethylsulfenylation of (hetero)arenes and thiols.
Scheme 35: PPh3/NaI-mediated trifluoromethylsulfenylation of indole derivatives.
Scheme 36: PPh3/n-Bu4NI mediated trifluoromethylsulfenylation of thiophenol derivatives.
Scheme 37: PPh3/Et3N mediated trifluoromethylsulfinylation of benzylamine.
Scheme 38: PCy3-mediated trifluoromethylsulfinylation of azaarenes, amines and phenols.
Scheme 39: Mono- and dichlorination of carbon acids.
Scheme 40: Monochlorination of (N-aryl-N-hydroxy)acylacetamides.
Scheme 41: Examples of the synthesis of heterocycles fused with β-lactams through a chlorination/cyclisation p...
Scheme 42: Enantioselective chlorination of β-ketoesters and oxindoles.
Scheme 43: Enantioselective chlorination of 3-acyloxazolidin-2-one derivatives (NMM = N-methylmorpholine).
CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na
- Hélène Guyon,
- Hélène Chachignon and
- Dominique Cahard
Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272
- the crucial role of aerial oxygen in the catalytic cycle (see mechanism in Scheme 42). Simultaneously, Tang and co-workers reported a greener strategy for the trifluoromethylation of imidazoheterocycles with CF3SO2Na in a recyclable mixed medium of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim
Graphical Abstract
Scheme 1: Trifluoromethylation of enol acetates by Langlois.
Scheme 2: Trifluoromethylation of (het)aryl enol acetates.
Scheme 3: Mechanism for the trifluoromethylation of enol acetates.
Scheme 4: Oxidative trifluoromethylation of unactivated olefins and mechanistic pathway.
Scheme 5: Oxidative trifluoromethylation of acetylenic substrates.
Scheme 6: Metal free trifluoromethylation of styrenes.
Scheme 7: Synthesis of α-trifluoromethylated ketones by oxytrifluoromethylation of heteroatom-functionalised ...
Scheme 8: Catalysed photoredox trifluoromethylation of vinyl azides.
Scheme 9: Oxidative difunctionalisation of alkenyl MIDA boronates.
Scheme 10: Synthesis of β-trifluoromethyl ketones from cyclopropanols.
Scheme 11: Aryltrifluoromethylation of allylic alcohols.
Scheme 12: Cascade multicomponent synthesis of nitrogen heterocycles via azotrifluoromethylation of alkenes.
Scheme 13: Photocatalytic azotrifluoromethylation of alkenes with aryldiazonium salts and CF3SO2Na.
Scheme 14: Copper-promoted intramolecular aminotrifluoromethylation of alkenes with CF3SO2Na.
Scheme 15: Oxytrifluoromethylation of alkenes with CF3SO2Na and hydroxamic acid.
Scheme 16: Manganese-catalysed oxytrifluoromethylation of styrene derivatives.
Scheme 17: Oxytrifluoromethylation of alkenes with NMP/O2 and CF3SO2Na.
Scheme 18: Intramolecular oxytrifluoromethylation of alkenes.
Scheme 19: Hydrotrifluoromethylation of styrenyl alkenes and unactivated aliphatic alkenes.
Scheme 20: Hydrotrifluoromethylation of electron-deficient alkenes.
Scheme 21: Hydrotrifluoromethylation of alkenes by iridium photoredox catalysis.
Scheme 22: Iodo- and bromotrifluoromethylation of alkenes by CF3SO2Na/I2O5 or CF3SO2Na / NaBrO3.
Scheme 23: N-methyl-9-mesityl acridinium and visible-light-induced chloro-, bromo- and SCF3 trifluoromethylati...
Scheme 24: Carbotrifluoromethylation of N-arylacrylamides with CF3SO2Na / TBHP by Lipshutz.
Scheme 25: Carbotrifluoromethylation of N-arylacrylamides with CF3SO2Na/TBHP reported by Lei.
Scheme 26: Carbotrifluoromethylation of N-arylacrylamides with CF3SO2Na/(NH4)2S2O8.
Scheme 27: Metal-free carbotrifluoromethylation of N-arylacrylamides with CF3SO2Na/K2S2O8 reported by Wang.
Scheme 28: Metal-free carbotrifluoromethylation of N-arylacrylamides with CF3SO2Na/PIDA reported by Fu.
Scheme 29: Metal-free cascade trifluoromethylation/cyclisation of N-arylmethacrylamides (a) and enynes (b) wit...
Scheme 30: Trifluoromethylation/cyclisation of N-arylcinnamamides: Synthesis of 3,4-disubstituted dihydroquino...
Scheme 31: Trifluoromethylation/cyclisation of aromatic-containing unsaturated ketones.
Scheme 32: Chemo- and regioselective cascade trifluoromethylation/heteroaryl ipso-migration of unactivated alk...
Scheme 33: Copper-mediated 1,2-bis(trifluoromethylation) of alkenes.
Scheme 34: Trifluoromethylation of aromatics with CF3SO2Na reported by Langlois.
Scheme 35: Baran’s oxidative C–H trifluoromethylation of heterocycles.
Scheme 36: Trifluoromethylation of acetanilides and anilines.
Scheme 37: Trifluoromethylation of heterocycles in water.
Scheme 38: Trifluoromethylation of coumarins in a continuous-flow reactor.
Scheme 39: Oxidative trifluoromethylation of coumarins, quinolines and pyrimidinones.
Scheme 40: Oxidative trifluoromethylation of pyrimidinones and pyridinones.
Scheme 41: Phosphovanadomolybdic acid-catalysed direct C−H trifluoromethylation.
Scheme 42: Oxidative trifluoromethylation of imidazopyridines and imidazoheterocycles.
Scheme 43: Oxidative trifluoromethylation of imidazoheterocycles and imidazoles in ionic liquid/water.
Scheme 44: Oxidative trifluoromethylation of 8-aminoquinolines.
Scheme 45: Oxidative trifluoromethylation of various 8-aminoquinolines using the supported catalyst CS@Cu(OAc)2...
Scheme 46: Oxidative trifluoromethylation of the naphthylamide 70.
Scheme 47: Oxidative trifluoromethylation of various arenes in the presence of CF3SO2Na and sodium persulfate.
Scheme 48: Trifluoromethylation of electron-rich arenes and unsymmetrical biaryls with CF3SO2Na in the presenc...
Figure 1: Trifluoromethylated coumarin and flavone.
Scheme 49: Metal-free trifluoromethylation catalysed by a photoredox organocatalyst.
Scheme 50: Quinone-mediated trifluoromethylation of arenes and heteroarenes.
Scheme 51: Metal- and oxidant-free photochemical trifluoromethylation of arenes.
Scheme 52: Copper-mediated trifluoromethylation of arenediazonium tetrafluoroborates.
Scheme 53: Oxidative trifluoromethylation of aryl- and heteroarylboronic acids.
Scheme 54: Oxidative trifluoromethylation of aryl- and vinylboronic acids.
Scheme 55: Oxidative trifluoromethylation of unsaturated potassium organotrifluoroborates.
Scheme 56: Oxidative trifluoromethylation of (hetero)aryl- and vinyltrifluoroborates.
Scheme 57: Copper−catalysed decarboxylative trifluoromethylation of cinnamic acids.
Scheme 58: Iron-mediated decarboxylative trifluoromethylation of α,β-unsaturated carboxylic acids.
Scheme 59: Cu/Ag-catalysed decarboxylative trifluoromethylation of cinnamic acids.
Scheme 60: I2O5-Promoted decarboxylative trifluoromethylation of cinnamic acids.
Scheme 61: Silver(I)-catalysed denitrative trifluoromethylation of β-nitrostyrenes.
Scheme 62: Copper-catalysed direct trifluoromethylation of styrene derivatives.
Scheme 63: Transition-metal-free synthesis of β-trifluoromethylated enamines.
Scheme 64: I2O5-mediated iodotrifluoromethylation of alkynes.
Scheme 65: Silver-catalysed tandem trifluoromethylation/cyclisation of aryl isonitriles.
Scheme 66: Photoredox trifluoromethylation of 2-isocyanobiphenyls.
Scheme 67: Trifluoromethylation of potassium alkynyltrifluoroborates with CF3SO2Na.
Scheme 68: N-trifluoromethylation of nitrosoarenes with CF3SO2Na (SQ: semiquinone).
Scheme 69: Trifluoromethylation of disulfides with CF3SO2Na.
Scheme 70: Trifluoromethylation of thiols with CF3SO2Na/I2O5.
Scheme 71: Electrophilic trifluoromethylsulfenylation by means of CF3SO2Na/(EtO)2P(O)H/CuCl/DMSO.
Scheme 72: Electrophilic trifluoromethylsulfenylation by means of CF3SO2Na/(EtO)2P(O)H/TMSCl.
Scheme 73: Electrophilic trifluoromethylsulfenylation by means of CF3SO2Na/PPh3/N-chlorophthalimide.
Scheme 74: Electrophilic trifluoromethylsulfenylation by means of CF3SO2Na/PCl3.
Scheme 75: Electrophilic trifluoromethylsulfenylation by means of CF3SO2Na/PCl3.
Scheme 76: Trifluoromethylsulfenylation of aryl iodides with in situ generated CuSCF3 (DMI: 1,3-dimethyl-2-imi...
Scheme 77: Pioneering trifluoromethylsulfinylation of N, O, and C-nucleophiles.
Scheme 78: Trifluoromethylsulfinylation of (1R,2S)-ephedrine (Im: imidazole; DIEA: N,N-diisopropylethylamine).
Scheme 79: Trifluoromethylsulfinylation of substituted benzenes with CF3SO2Na/CF3SO3H.
Scheme 80: Trifluoromethylsulfinylation of indoles with CF3SO2Na/P(O)Cl3.
Scheme 81: Trifluoromethylsulfinylation of indoles with CF3SO2Na/PCl3.
Scheme 82: Formation of triflones from benzyl bromides (DMA: dimethylacetamide).
Scheme 83: Formation of α-trifluoromethylsulfonyl ketones, esters, and amides.
Scheme 84: Allylic trifluoromethanesulfonylation of aromatic allylic alcohols.
Scheme 85: Copper-catalysed couplings of aryl iodonium salts with CF3SO2Na.
Scheme 86: Palladium-catalysed trifluoromethanesulfonylation of aryl triflates and chlorides with CF3SO2Na.
Scheme 87: Copper-catalysed coupling of arenediazonium tetrafluoroborates with CF3SO2Na.
Scheme 88: Synthesis of phenyltriflone via coupling of benzyne with CF3SO2Na.
Scheme 89: Synthesis of 1-trifluoromethanesulfonylcyclopentenes from 1-alkynyl-λ3-bromanes and CF3SO2Na.
Scheme 90: One-pot synthesis of functionalised vinyl triflones.
Scheme 91: Regioselective synthesis of vinyltriflones from styrenes.
Scheme 92: Trifluoromethanesulfonylation of alkynyl(phenyl) iodonium tosylates by CF3SO2Na.
Scheme 93: Synthesis of thio- and selenotrifluoromethanesulfonates.
Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity
- Tathagata Mukherjee,
- Soumik Biswas,
- Andreas Ehnbom,
- Subrata K. Ghosh,
- Ibrahim El-Zoghbi,
- Nattamai Bhuvanesh,
- Hassan S. Bazzi and
- John A. Gladysz
Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246
- dichlorides [17], and aromatic iodine(III) bis(acetates) [16] and dichlorides [17]. The bis(carboxylates) have been employed as recyclable reagents for oxidations of organic substrates [16][18][19], and some of the dichlorides are depicted in Scheme 1. Others have described additional fluorous iodine(III
Graphical Abstract
Scheme 1: Some previously reported iodine(III) dichlorides relevant to this work.
Scheme 2: Syntheses of fluorous compounds of the formula RfnCH2X.
Scheme 3: Syntheses of fluorous compounds of the formula CF3CF2CF2O(CF(CF3)CF2O)xCF(CF3)CH2X'.
Scheme 4: Attempted syntheses of aliphatic fluorous iodine(III) dichlorides RfnICl2.
Scheme 5: Syntheses of aromatic fluorous compounds with one perfluoroalkyl group.
Scheme 6: Syntheses of aromatic fluorous compounds with two perfluoroalkyl groups.
Figure 1: Partial 1H NMR spectra (sp2 CH, 500 MHz, CDCl3) relating to the reaction of 1,3,5-(Rf6)2C6H3I and Cl...
Figure 2: Two views of the molecular structure of 1,3,5-(Rf6)2C6H3I with thermal ellipsoids at the 50% probab...
Figure 3: Ball-and-stick and space filling representations of the unit cell of 1,3,5-(Rf6)2C6H3I.
Figure 4: Free energies of chlorination of relevant aryl and alkyl iodides to the corresponding iodine(III) d...
Scheme 7: Other relevant fluorous compounds and reactions.
Figure 5: Views of the helical motif of the perfluorohexyl segments in crystalline 1,3,5-(Rf6)2C6H3I (left) a...
Ni nanoparticles on RGO as reusable heterogeneous catalyst: effect of Ni particle size and intermediate composite structures in C–S cross-coupling reaction
- Debasish Sengupta,
- Koushik Bhowmik,
- Goutam De and
- Basudeb Basu
Beilstein J. Org. Chem. 2017, 13, 1796–1806, doi:10.3762/bjoc.13.174
- -coupling reactions and are applicable to a diverse range of coupling partners. The catalytic performance is primarily dependent on the NP sizes of the Ni species. The electron-rich planar surface of RGO helps in stabilizing the NPs and prevents agglomeration making them recyclable with almost equal
Graphical Abstract
Figure 1: Recycling experiments of Ni/RGO-40 catalyst in C−S cross-coupling reaction between 4-iodoanisole an...
Figure 2: (a) Raman spectrum of fresh Ni/RGO-40 and (b) recovered catalyst after the first cycle of C–S coupl...
Figure 3: (a) XRD of fresh Ni/RGO-40 and (b) the recovered catalyst after the first cycle of C–S coupling.
Figure 4: HRXPS of Ni in (a) Ni/RGO-40 catalyst recovered after the first cycle of the reaction. (b) Deconvol...
Figure 5: XRD of Ni(OH)2/RGO, prepared separately.
Figure 6: Proposed mechanism for the RGO-supported Ni-catalyzed C–S cross-coupling reaction.
Figure 7: TEM image of (a) Ni/RGO-40 before usage as a catalyst (for comparison, reprinted with permission fr...
Encaging palladium(0) in layered double hydroxide: A sustainable catalyst for solvent-free and ligand-free Heck reaction in a ball mill
- Wei Shi,
- Jingbo Yu,
- Zhijiang Jiang,
- Qiaoling Shao and
- Weike Su
Beilstein J. Org. Chem. 2017, 13, 1661–1668, doi:10.3762/bjoc.13.160
- . Thus, Pd catalysts anchored on heterogeneous solid support materials such as MCM-41 [29], alumina [30], silica [31], carbon nanotubes [32], microporous polymers [33], SBA-15 [34], or some dendrimers [35] were preferred to develop a ligandless and recyclable catalyst system. However, to the best of our
- at least five times efficiently without significant loss in catalytic activity, resulting in almost no change in the yields. Hence, the reusability of Pd/MgAl-LDHs is one of the major advantages for Heck reactions under HSBM conditions. Conclusion In summary, a supported and recyclable Pd catalyst (Pd
Graphical Abstract
Scheme 1: Supported catalysts in cross-coupling reactions. MM represents mixer mill; PM represents planetary ...
Figure 1: The XRD patterns for the samples of MgAl-LDHs, MgAl-LDHs-PdCl42− and Pd/MgAl-LDHs.
Scheme 2: Selected model reaction.
Figure 2: Examination of the milling-ball filling degree (ΦMB) and milling-ball sizes on the yield of 3aa. Re...
Figure 3: Examination of ball-milling time and rotation speed on the yield of 3aa. Reaction conditions: 1a (1...
Figure 4: Substrate scope of Pd/MgAl-LDHs catalyzed Heck reactions. Reaction conditions unless otherwise note...
Scheme 3: Pd/MgAl-LDHs catalyzed Heck reactions of heteroaryl bromides. Reaction conditions unless otherwise ...
Figure 5: Recycling studies of the Pd/MgAl-LDH catalyst for Heck reactions. Reaction conditions: 1i or 1m (1....
Chemical systems, chemical contiguity and the emergence of life
- Terrence P. Kee and
- Pierre-Alain Monnard
Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155
- , and a nucleobase, 8-oxoguanine, serving as recyclable electron donor to trigger the redox cleavage of the precursor molecule, [71] was also found to be enhanced by the presence of pre-formed fatty acid vesicles. In aqueous media, both parts of the photochemical catalyst needed to be covalently linked
Graphical Abstract
Figure 1: (A) Possible approaches to the historical reconstruction. Two complementary approaches exist: top-d...
Figure 2: The bottom-up approach research strategies. (A) Each protocell component (vide infra) can be invest...
Figure 3: A putative scenario for the evolution of chemical systems towards protocells. (A) Prebiotic chemist...
Glyco-gold nanoparticles: synthesis and applications
- Federica Compostella,
- Olimpia Pitirollo,
- Alessandro Silvestri and
- Laura Polito
Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100
- -antibiotic conjugates, were prepared and resulted able to overcome antibiotic resistance of microbial biofilms, since CA NPs render streptomycin more accessible to biofilms, thereby more available to interact with biofilm bacteria [89]. Similarly, a novel recyclable E.coli-specific killing GAuNP
Graphical Abstract
Figure 1: Schematic overview on the glyco-gold nanoparticles synthetic approaches.
Figure 2: Glyco-gold nanoparticles: metallic core and glyco-coating contribute to the production of the versa...
Figure 3: The protein–carbohydrate interactions analyzed by conventional dark field microscopy. The interacti...
Figure 4: Copper-free cycloaddition (SPAAC) of azido galactoside on cyclooctyne and schematic depiction of Au...
Figure 5: A photoaffinity labeling (PAL) approach based on glyco-gold nanoparticles is able to recognize and ...
Figure 6: Design of the fiber-type “Sugar Chips”. AuNPs are firstly immobilized on an optical fiber functiona...
Figure 7: Design of GAuNPs, displaying both sugar residues and the anticancer Au(I)PPh3. Reprinted with permi...
Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis
- Flavio Fanelli,
- Giovanna Parisi,
- Leonardo Degennaro and
- Renzo Luisi
Beilstein J. Org. Chem. 2017, 13, 520–542, doi:10.3762/bjoc.13.51
- , the catalyst can be fixed on a suitable hardware, and the reaction mixture allowed to flow through the system. The use of recyclable catalysts in continuous-flow conditions represents an innovative strategy for the development of more environmentally friendly synthesis. In the last decade, organic
- synthesis and application of a recyclable immobilized analogue of benzotetramisole (BMT) used in a catalytic enantioselective Michael addition/cyclization reactions under continuous-flow conditions (Scheme 11) [60]. Resin-bound catalyst 10 was swollen with dichloromethane in a medium-pressure chromatography
- in Scheme 16, diazo species 18 could be generated from simple carbonyls 15 and hydrazine (16). Intermediate hydrazones 17 can be converted into the corresponding diazo compounds by oxidation using a recyclable oxidant based on N-iodo-p-toluenesulfonamide potassium salt. The possibility to regenerate
Graphical Abstract
Figure 1: Microreactor technologies and flow chemistry for a sustainable chemistry.
Scheme 1: A flow microreactor system for the generation and trapping of highly unstable carbamoyllithium spec...
Scheme 2: Flow synthesis of functionalized α-ketoamides.
Scheme 3: Reactions of benzyllithiums.
Scheme 4: Trapping of benzyllithiums bearing carbonyl groups enabled by a flow microreactor. (Adapted with pe...
Scheme 5: External trapping of chloromethyllithium in a flow microreactor system.
Scheme 6: Scope for the direct tert-butoxycarbonylation using a flow microreactor system.
Scheme 7: Control of anionic Fries rearrangement reactions by using submillisecond residence time. (Adapted w...
Figure 2: Chip microreactor (CMR) fabricated with six layers of polyimide films. (Reproduced with permission ...
Scheme 8: Flow microreactor system for lithiation, borylation, Suzuki–Miyaura coupling and selected examples ...
Scheme 9: Experimental setup for the flow synthesis of 2-fluorobi(hetero)aryls by directed lithiation, zincat...
Scheme 10: Experimental setup for the coupling of fluoro-substituted pyridines. (Adapted with permission from [53]...
Scheme 11: Continuous flow process setup for the preparation of 11 (Reproduced with permission from [54], copyrigh...
Scheme 12: Continuous-flow photocatalytic oxidation of thiols to disulfides.
Scheme 13: Trifluoromethylation by continuous-flow photoredox catalysis.
Scheme 14: Flow photochemical synthesis of 6(5H)-phenanthridiones from 2-chlorobenzamides.
Scheme 15: Synthesis of biaryls 14a–g under photochemical flow conditions.
Scheme 16: Flow oxidation of hydrazones to diazo compounds.
Scheme 17: Synthetic use of flow-generated diazo compounds.
Scheme 18: Ley’s flow approach for the generation of diazo compounds.
Scheme 19: Iterative strategy for the sequential coupling of diazo compounds.
Scheme 20: Integrated synthesis of Bakuchiol precursor via flow-generated diazo compounds.
Scheme 21: Kappe’s continuous-flow reduction of olefines with diimide.
Scheme 22: Multi-injection setup for the reduction of artemisinic acid.
Scheme 23: Flow reactor system for multistep synthesis of (S)-rolipram. Pumps are labelled a, b, c, d and e; L...
Figure 3: Reconfigurable modules and flowcharts for API synthesis. (Reproduced with permission from [85], copyrig...
Figure 4: Reconfigurable system for continuous production and formulation of APIs. (Reproduced with permissio...
