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Search for "zinc iodide" in Full Text gives 9 result(s) in Beilstein Journal of Organic Chemistry.
Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group
- Chuanhua Qu,
- Run Huang,
- Yong Li,
- Tong Liu,
- Yuan Chen and
- Guiting Song
Beilstein J. Org. Chem. 2021, 17, 2822–2831, doi:10.3762/bjoc.17.193
- -toluenesulfonylmethyl isocyanide (TosMIC) by using respectively zinc iodide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as catalysts were developed. The distinguishing feature of this method is that TosMIC plays a dual role from the same substrates in the reaction: as a sulfonyl source or as an isonitrile source. The
Graphical Abstract
Figure 1: Selected bioactive compounds.
Scheme 1: The chemistry of TosMIC in the reactions with olefins.
Scheme 2: ZnI2-catalyzed C–S-bond cleavage of TosMIC for the synthesis of diarylmethyl sulfones 3a–m. Reactio...
Scheme 3: Cases encountered by other p-QMs examinations.
Figure 2: Crystal structure of diarylmethyl sulfone 3e.
Scheme 4: DBU-catalyzed 1,6-conjugate addition for the synthesis of isonitrile diarylmethanes 4a–h. Reaction ...
Scheme 5: Synthetic applications of the synthesized compound 3b.
Scheme 6: Mechanistic studies and proposed mechanism.
Recent advances in the syntheses of anthracene derivatives
- Giovanni S. Baviera and
- Paulo M. Donate
Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131
- metathesis strategy to synthesize benz[a]anthracenes. Green synthesis of oxa-aza-benzo[a]anthracene and oxa-aza-phenanthrene derivatives. Triple benzannulation of substituted naphtalene via a 1,3,6-naphthotriyne synthetic equivalent. Zinc iodide-catalyzed Diels–Alder reactions with 1,3-dienes and aroyl
Graphical Abstract
Figure 1: Examples of anthracene derivatives and their applications.
Scheme 1: Rhodium-catalyzed oxidative coupling reactions of arylboronic acids with internal alkynes.
Scheme 2: Rhodium-catalyzed oxidative benzannulation reactions of 1-adamantoyl-1-naphthylamines with internal...
Scheme 3: Gold/bismuth-catalyzed cyclization of o-alkynyldiarylmethanes.
Scheme 4: [2 + 2 + 2] Cyclotrimerization reactions with alkynes/nitriles in the presence of nickel and cobalt...
Scheme 5: Cobalt-catalyzed [2 + 2 + 2] cyclotrimerization reactions with bis(trimethylsilyl)acetylene (23).
Scheme 6: [2 + 2 + 2] Alkyne-cyclotrimerization reactions catalyzed by a CoCl2·6H2O/Zn reagent.
Scheme 7: Pd(II)-catalyzed sp3 C–H alkenylation of diphenyl carboxylic acids with acrylates.
Scheme 8: Pd(II)-catalyzed sp3 C–H arylation with o-tolualdehydes and aryl iodides.
Scheme 9: Alkylation of arenes with aromatic aldehydes in the presence of acetyl bromide and ZnBr2/SiO2.
Scheme 10: BF3·H2O-catalyzed hydroxyalkylation of arenes with aromatic dialdehyde 44.
Scheme 11: Bi(OTf)3-promoted Friedel–Crafts alkylation of triarylmethanes and aromatic acylals and of arenes a...
Scheme 12: Reduction of anthraquinones by using Zn/pyridine or Zn/NaOH reductive methods.
Scheme 13: Two-step route to novel substituted Indenoanthracenes.
Scheme 14: Synthesis of 1,8-diarylanthracenes through Suzuki–Miyaura coupling reaction in the presence of Pd-P...
Scheme 15: Synthesis of five new substituted anthracenes by using LAH as reducing agent.
Scheme 16: One-pot procedure to synthesize substituted 9,10-dicyanoanthracenes.
Scheme 17: Reduction of bromoanthraquinones with NaBH4 in alkaline medium.
Scheme 18: In(III)-catalyzed reductive-dehydration intramolecular cycloaromatization of 2-benzylic aromatic al...
Scheme 19: Acid-catalyzed cyclization of new O-protected ortho-acetal diarylmethanols.
Scheme 20: Lewis acid-mediated regioselective cyclization of asymmetric diarylmethine dipivalates and diarylme...
Scheme 21: BF3·OEt2/CF3SO3H-mediated cyclodehydration reactions of 2-(arylmethyl)benzaldehydes and 2-(arylmeth...
Scheme 22: Synthesis of 2,3,6,7-anthracenetetracarbonitrile (90) by double Wittig reaction followed by deprote...
Scheme 23: Homo-elongation protocol for the synthesis of substituted acene diesters/dinitriles.
Scheme 24: Synthesis of two new parental BN anthracenes via borylative cyclization.
Scheme 25: Synthesis of substituted anthracenes from a bifunctional organomagnesium alkoxide.
Scheme 26: Palladium-catalyzed tandem C–H activation/bis-cyclization of propargylic carbonates.
Scheme 27: Ruthenium-catalyzed C–H arylation of acetophenone derivatives with arenediboronates.
Scheme 28: Pd-catalyzed intramolecular cyclization of (Z,Z)-p-styrylstilbene derivatives.
Scheme 29: AuCl-catalyzed double cyclization of diiodoethynylterphenyl compounds.
Scheme 30: Iodonium-induced electrophilic cyclization of terphenyl derivatives.
Scheme 31: Oxidative photocyclization of 1,3-distyrylbenzene derivatives.
Scheme 32: Oxidative cyclization of 2,3-diphenylnaphthalenes.
Scheme 33: Suzuki-Miyaura/isomerization/ring closing metathesis strategy to synthesize benz[a]anthracenes.
Scheme 34: Green synthesis of oxa-aza-benzo[a]anthracene and oxa-aza-phenanthrene derivatives.
Scheme 35: Triple benzannulation of substituted naphtalene via a 1,3,6-naphthotriyne synthetic equivalent.
Scheme 36: Zinc iodide-catalyzed Diels–Alder reactions with 1,3-dienes and aroyl propiolates followed by intra...
Scheme 37: H3PO4-promoted intramolecular cyclization of substituted benzoic acids.
Scheme 38: Palladium-catalyzed intermolecular direct acylation of aromatic aldehydes and o-iodoesters.
Scheme 39: Cycloaddition/oxidative aromatization of quinone and β-enamino esters.
Scheme 40: ʟ-Proline-catalyzed [4 + 2] cycloaddition reaction of naphthoquinones and α,β-unsaturated aldehydes....
Scheme 41: Iridium-catalyzed [2 + 2 + 2] cycloaddition of a 1,2-bis(propiolyl)benzene derivative with alkynes.
Scheme 42: Synthesis of several anthraquinone derivatives by using InCl3 and molecular iodine.
Scheme 43: Indium-catalyzed multicomponent reactions employing 2-hydroxy-1,4-naphthoquinone (186), β-naphthol (...
Scheme 44: Synthesis of substituted anthraquinones catalyzed by an AlCl3/MeSO3H system.
Scheme 45: Palladium(II)-catalyzed/visible light-mediated synthesis of anthraquinones.
Scheme 46: [4 + 2] Anionic annulation reaction for the synthesis of substituted anthraquinones.
Fluorinated phenylalanines: synthesis and pharmaceutical applications
- Laila F. Awad and
- Mohammed Salah Ayoup
Beilstein J. Org. Chem. 2020, 16, 1022–1050, doi:10.3762/bjoc.16.91
- ] (Scheme 41). An alternative approach to the difluorinated compound 168a was achieved by the condensation of 164a with (S)-1-phenylethylamine (169), to give the imine 170. Heating of imine 170 with TMSCN in the presence of zinc iodide [82] generated the nitrile 171 as a 1:1 mixture of diastereoisomers
Graphical Abstract
Figure 1: Categories I–V of fluorinated phenylalanines.
Scheme 1: Synthesis of fluorinated phenylalanines via Jackson’s method.
Scheme 2: Synthesis of all-cis-tetrafluorocyclohexylphenylalanines.
Scheme 3: Synthesis of ʟ-4-[sulfono(difluoromethyl)]phenylalanine (nPt: neopentyl, TCE: trichloroethyl).
Scheme 4: Synthesis of ʟ-4-[sulfono(difluoromethyl)]phenylalanine derivatives 17.
Scheme 5: Synthesis of fluorinated Phe analogues from Cbz-protected aminomalonates.
Scheme 6: Synthesis of tetrafluorophenylalanine analogues via the 3-methyl-4-imidazolidinone auxiliary 25.
Scheme 7: Synthesis of tetrafluoro-Phe derivatives via chiral auxiliary 31.
Scheme 8: Synthesis of 2,5-difluoro-Phe and 2,4,5-trifluoro-Phe via Schöllkopf reagent 34.
Scheme 9: Synthesis of 2-fluoro- and 2,6-difluoro Fmoc-Phe derivatives starting from chiral auxiliary 39.
Scheme 10: Synthesis of 2-[18F]FPhe via chiral auxiliary 43.
Scheme 11: Synthesis of FPhe 49a via photooxidative cyanation.
Scheme 12: Synthesis of FPhe derivatives via Erlenmeyer azalactone synthesis.
Scheme 13: Synthesis of (R)- and (S)-2,5-difluoro Phe via the azalactone method.
Scheme 14: Synthesis of 3-bromo-4-fluoro-(S)-Phe (65).
Scheme 15: Synthesis of [18F]FPhe via radiofluorination of phenylalanine with [18F]F2 or [18F]AcOF.
Scheme 16: Synthesis of 4-borono-2-[18F]FPhe.
Scheme 17: Synthesis of protected 4-[18F]FPhe via arylstannane derivatives.
Scheme 18: Synthesis of FPhe derivatives via intermediate imine formation.
Scheme 19: Synthesis of FPhe derivatives via Knoevenagel condensation.
Scheme 20: Synthesis of FPhe derivatives 88a,b from aspartic acid derivatives.
Scheme 21: Synthesis of 2-(2-fluoroethyl)phenylalanine derivatives 93 and 95.
Scheme 22: Synthesis of FPhe derivatives via Zn2+ complexes.
Scheme 23: Synthesis of FPhe derivatives via Ni2+ complexes.
Scheme 24: Synthesis of 3,4,5-trifluorophenylalanine hydrochloride (109).
Scheme 25: Synthesis of FPhe derivatives via phenylalanine aminomutase (PAM).
Scheme 26: Synthesis of (R)-2,5-difluorophenylalanine 115.
Scheme 27: Synthesis of β-fluorophenylalanine via 2-amino-1,3-diol derivatives.
Scheme 28: Synthesis of β-fluorophenylalanine derivatives via the oxazolidinone chiral auxiliary 122.
Scheme 29: Synthesis of β-fluorophenylalanine from pyruvate hemiketal 130.
Scheme 30: Synthesis of β-fluorophenylalanine (136) via fluorination of β-hydroxyphenylalanine (137).
Scheme 31: Synthesis of β-fluorophenylalanine from aziridine derivatives.
Scheme 32: Synthesis of β-fluorophenylalanine 136 via direct fluorination of pyruvate esters.
Scheme 33: Synthesis of β-fluorophenylalanine via fluorination of ethyl 3-phenylpyruvate enol using DAST.
Scheme 34: Synthesis of β-fluorophenylalanine derivatives using photosensitizer TCB.
Scheme 35: Synthesis of β-fluorophenylalanine derivatives using Selectflour and dibenzosuberenone.
Scheme 36: Synthesis of protected β-fluorophenylalanine via aziridinium intermediate 150.
Scheme 37: Synthesis of β-fluorophenylalanine derivatives via fluorination of α-hydroxy-β-aminophenylalanine d...
Scheme 38: Synthesis of β-fluorophenylalanine derivatives from α- or β-hydroxy esters 152a and 155.
Scheme 39: Synthesis of a series of β-fluoro-Phe derivatives via Pd-catalyzed direct fluorination of β-methyle...
Scheme 40: Synthesis of series of β-fluorinated Phe derivatives using quinoline-based ligand 162 in the Pd-cat...
Scheme 41: Synthesis of β,β-difluorophenylalanine derivatives from 2,2-difluoroacetaldehyde derivatives 164a,b....
Scheme 42: Synthesis of β,β-difluorophenylalanine derivatives via an imine chiral auxiliary.
Scheme 43: Synthesis of α-fluorophenylalanine derivatives via direct fluorination of protected Phe 174.
Figure 2: Structures of PET radiotracers of 18FPhe derivatives.
Figure 3: Structures of melfufen (179) and melphalan (180) anticancer drugs.
Figure 4: Structure of gastrazole (JB95008, 181), a CCK2 receptor antagonist.
Figure 5: Dual CCK1/CCK2 antagonist 182.
Figure 6: Structure of sitagliptin (183), an antidiabetic drug.
Figure 7: Structure of retaglpitin (184) and antidiabetic drug.
Figure 8: Structure of evogliptin (185), an antidiabetic drug.
Figure 9: Structure of LY2497282 (186) a DPP-4 inhibitor for the treatment of type II diabetes.
Figure 10: Structure of ulimorelin (187).
Figure 11: Structure of GLP1R (188).
Figure 12: Structures of Nav1.7 blockers 189 and 190.
Architecture and synthesis of P,N-heterocyclic phosphine ligands
- Wisdom A. Munzeiwa,
- Bernard Omondi and
- Vincent O. Nyamori
Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35
- were induced by reacting with zinc iodide and they could exist in the complexed state as structures 115 and 116. The substituents on the amine nitrogen affect the reaction conditions as well as the stability of the P–N bond. Wassenaar et al. [22] reported on a flexible click-phosphine ligand (120
Graphical Abstract
Scheme 1: Synthesis of pyridylphosphine ligands.
Figure 1: Pyridylphosphine ligands.
Scheme 2: Synthesis of piperidyl- and oxazinylphosphine ligands.
Scheme 3: Synthesis of linear multi-chelate pyridylphosphine ligands.
Scheme 4: Synthesis of chiral acetal pyridylphosphine ligands.
Scheme 5: Synthesis of diphenylphosphine-substituted triazine ligands.
Scheme 6: Synthesis of (pyridine-2-ylmethyl)phosphine ligands.
Scheme 7: Synthesis of diphosphine pyrrole ligands.
Scheme 8: Synthesis of 4,5-diazafluorenylphosphine ligands.
Scheme 9: Synthesis of thioether-containing pyridyldiphosphine ligands starting from ethylene sulfide and dip...
Scheme 10: Synthesis of monoterpene-derived phosphine pyridine ligands.
Scheme 11: Synthesis of N-phenylphosphine-substituted imidazole ligands.
Scheme 12: Synthesis of triazol-4-ylphosphine ligands.
Scheme 13: Synthesis of phosphanyltriazolopyridines and product selectivity depending on the substituents’ eff...
Scheme 14: Synthesis of PTA-phosphine ligands.
Scheme 15: Synthesis of isomeric phosphine dipyrazole ligands by varying the reaction temperature.
Scheme 16: Synthesis of N-tethered phosphine imidazolium ligands (route A) and diphosphine imidazolium ligands...
Scheme 17: Synthesis of {1-[2-(pyridin-2-yl)- (R = CH) and {1-[2-(pyrazin-2-yl)quinazolin-4-yl]naphthalen-2-yl...
Scheme 18: Synthesis of oxazolylindolylphosphine ligands 102.
Scheme 19: Synthesis of pyrrolylphosphine ligands.
Scheme 20: Synthesis of phosphine guanidinium ligands.
Scheme 21: Synthesis of a polydentate aminophosphine ligand.
Scheme 22: Synthesis of quinolylphosphine ligands.
Scheme 23: Synthesis of N-(triazolylmethyl)phosphanamine ligands.
Figure 2: Triazolylphosphanamine ligands synthesized by Wassenaar’s method [22].
Scheme 24: Synthesis of oxazaphosphorines.
Scheme 25: Synthesis of paracyclophane pyridylphosphine ligands.
Scheme 26: Synthesis of triazolylphosphine ligands.
Figure 3: Click-phosphine ligands.
Scheme 27: Ferrocenyl pyridylphosphine imine ligands.
Scheme 28: Synthesis of phosphinooxazolines (PHOX).
Scheme 29: Synthesis of ferrocenylphosphine oxazoles.
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
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 selective removal of the secondary hydroxy group from ortho-dithioacetal-substituted diarylmethanols
- Anna Czarnecka,
- Emilia Kowalska,
- Agnieszka Bodzioch,
- Joanna Skalik,
- Marek Koprowski,
- Krzysztof Owsianik and
- Piotr Bałczewski
Beilstein J. Org. Chem. 2018, 14, 1229–1237, doi:10.3762/bjoc.14.105
- % yields and is recommended for the substrates containing sulfur atoms, for which transition metal-induced reactions fail. Keywords: diarylmethanes; diarylmethanols; 1,3-dithiane; selective reduction; sodium cyanoborohydride; zinc iodide; Introduction In last decades, diarylmethanes, such as I–IV and
- ortho-1,3-dithianylaryl(aryl)methanols leading to ortho-1,3-dithianylaryl(aryl)methanes using the ZnI2-Na(CN)BH3 reductive system (Scheme 1). The use of zinc iodide is critical in this system. It was used for the first time in dichloroethane by Lau et al. to reduce aryl ketones, aldehydes, benzylic
Graphical Abstract
Figure 1: Structures of biologically active diarylmethanes and commercially available pharmaceuticals based o...
Scheme 1: Various synthetic approaches to diarylmethanols (literature review and this work).
Scheme 2: A general strategy for the synthesis of ortho-1,3-dithianylaryl(aryl)methanols 5 and 6, and their r...
Scheme 3: Attempts of the OH removal in ortho-1,3-dithianyl- 6b and ortho-1,3-dioxanylaryl(aryl)methanols 9 u...
Regioselective palladium-catalyzed ring-opening reactions of C1-substituted oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylates
- Michael Edmunds,
- Mohammed Abdul Raheem,
- Rebecca Boutin,
- Katrina Tait and
- William Tam
Beilstein J. Org. Chem. 2016, 12, 239–244, doi:10.3762/bjoc.12.25
- % respectively (Table 1, entries 9 and 4). The Lewis acid additives gave a large range of yields (Table 1, entries 10–14). Iron and aluminium chlorides gave low yields (22%, Table 1, entry 10 and 29%, entry 11), zirconium chloride and zinc iodide gave moderate yields (47%, Table 1, entry 12 and 48%, entry 13
Graphical Abstract
Scheme 1: Palladium-catalyzed ring-opening reactions of oxabenzonorbornadiene.
Scheme 2: Palladium-catalyzed ring-opening of 1 with p-iodotoluene.
Scheme 3: Potential regioisomers from the palladium-catalyzed ring-opening reaction of 2 with aryl iodides.
Scheme 4: Palladium-catalyzed ring-opening of C1 substituted oxabenzonorbornadiene.
Scheme 5: Proposed mechanism for the palladium-catalyzed ring-opening reaction of oxanorbornadiene.
Electrochemical selenium- and iodonium-initiated cyclisation of hydroxy-functionalised 1,4-dienes
- Philipp Röse,
- Steffen Emge,
- Jun-ichi Yoshida and
- Gerhard Hilt
Beilstein J. Org. Chem. 2015, 11, 174–183, doi:10.3762/bjoc.11.18
- ]. The synthesis of the 1,4-dienes was then accomplished utilising the cobalt-catalyst precursor and reducing conditions in the presence of zinc iodide for abstracting the bromide anions at room temperature. The TMS-protected allylic alcohol was applied in the cobalt-catalysed 1,4-hydrovinylation process
- –10 mol %), zinc powder (10–20 mol %) and zinc iodide (10–20 mol %) were suspended in dichloromethane and stirred at room temperature for 20 min. Then the 1,3-butadiene (1.0 equiv) and the allyloxytrimethylsilane (1.2–2.0 equiv) were added and the mixture was stirred at room temperature until complete
- -catalysed 1,4-hydrovinylation of buta-1,3-dienes with allyl alcohol Cobalt dibromo(1,3-bis(diphenylphosphino)ethane) (5 mol %), zinc powder (10 mol %) and zinc iodide (10 mol %) were suspended in dichloromethane and stirred at room temperature for 20 min. Then the 1,3-butadiene (1.0 equiv) and allyl alcohol
Graphical Abstract
Scheme 1: Cobalt-catalysed 1,4-hydrovinylation.
Scheme 2: Electrochemical selenoalkoxylation of 2.
Scheme 3: Electrochemical iodoalkoxylation of 2.
N-Alkylated dinitrones from isosorbide as cross-linkers for unsaturated bio-based polyesters
- Oliver Goerz and
- Helmut Ritter
Beilstein J. Org. Chem. 2014, 10, 902–909, doi:10.3762/bjoc.10.88
- -toluenesulfonic acid, phenothiazine (98%), zinc iodide (98%), and boron trifluoride diethyl etherate (46%) were purchased from Sigma-Aldrich and used as received. Isosorbide (98%) and E-benzaldoxime (97%) were purchased from Alfa Aesar, and isosorbide was recrystallized from acetone/ethyl acetate. All used
- methyl 3-[benzylidene(oxido)amino]propanoate (3a): Methyl acrylate (2a, 0.86 g, 10 mmol) and benzaldoxime (1, 2.42 g, 20 mmol) were placed in a 100 mL round bottom flask and dissolved in 20 mL toluene. Zinc iodide (0.32 g, 1 mmol) and boron triflouride diethyl etherate (0.30 g, 1 mmol) were added. The
- ]. Synthesis of methyl 3-[benzylidene(oxido)amino]butanoate (3b): Methyl crotonate (2b, 1 g, 10 mmol) and benzaldoxime (1, 2.42 g, 20 mmol) were placed in a 100 mL round bottom flask and dissolved in 40 mL toluene. Zinc iodide (0.48 g, 1.5 mmol) and boron triflouride diethyl etherate (0.44 g, 1.5 mmol) were
Graphical Abstract
Scheme 1: Synthesis of Z-configurated model compounds 3a/b from E-benzaldoxime and acrylates 2a/b.
Figure 1: 1H NMR spectra of 3a (300 MHz, DMSO-d6).
Scheme 2: Proposed molecular interactions of nitron 3a and dimethyl itaconate (4).
Scheme 3: 1,3-Dipolaric cycloaddition of nitrones 3a/b with dimethyl itaconate (4).
Scheme 4: Synthetic route to bio-based dinitrones derived from isosorbide.
Scheme 5: Synthesis of poly(isosorbide itaconate -co- succinate) 13 from isosorbide (6), itaconic acid (11) a...
Figure 2: Oscillation measurements during thermal cross-linking of unsaturated polyester 13 with dinitrones 1...
