Search for "halogenation" in Full Text gives 100 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26
Graphical Abstract
Figure 1: List of photoredox catalysts used for C–H bond functionalizations.
Figure 2: List of metal-based photoredox catalysts used in this review article.
Figure 3: Jablonski diagram.
Figure 4: Photoredox catalysis via reductive or oxidative pathways. D = donor, A = acceptor, S = substrate, P...
Figure 5: Schematic representation of the combination of photoredox catalysis and transition metal catalysis.
Scheme 1: Weinreb amide C–H olefination.
Figure 6: Mechanism for the formation of 21 from 19 using photoredox catalyst 11.
Scheme 2: C–H olefination of phenolic ethers.
Scheme 3: Decarboxylative acylation of acetanilides.
Figure 7: Mechanism for the formation of 30 from acetanilide derivatives.
Scheme 4: Synthesis of fluorenone derivatives by intramolecular deoxygenative acylation of biaryl carboxylic ...
Figure 8: Mechanism for the photoredox-catalyzed synthesis of fluorenone derivatives.
Scheme 5: Synthesis of benzothiazoles via aerobic C–H thiolation.
Figure 9: Plausible mechanism for the construction of benzothiazoles from benzothioamides.
Scheme 6: Synthesis of benzothiazoles via oxidant-free C–H thiolation.
Figure 10: Mechanism involved in the synthesis of benzothiazoles via oxidant-free C–H thiolation.
Scheme 7: Synthesis of indoles via C–H cyclization of anilides with alkynes.
Scheme 8: Preparation of 3-trifluoromethylcoumarins via C–H cyclization of arylpropiolate esters.
Figure 11: Mechanistic pathway for the synthesis of coumarin derivatives via C–H cyclization.
Scheme 9: Monobenzoyloxylation without chelation assistance.
Figure 12: Plausible mechanism for the formation of 71 from 70.
Scheme 10: Aryl-substituted arenes prepared by inorganic photoredox catalysis using 12a.
Figure 13: Proposed mechanism for C–H arylations in the presence of 12a and a Pd catalyst.
Scheme 11: Arylation of purines via dual photoredox catalysis.
Scheme 12: Arylation of substituted arenes with an organic photoredox catalyst.
Scheme 13: C–H trifluoromethylation.
Figure 14: Proposed mechanism for the trifluoromethylation of 88.
Scheme 14: Synthesis of benzo-3,4-coumarin derivatives.
Figure 15: Plausible mechanism for the synthesis of substituted coumarins.
Scheme 15: Oxidant-free oxidative phosphonylation.
Figure 16: Mechanism proposed for the phosphonylation reaction of 100.
Scheme 16: Nitration of anilines.
Figure 17: Plausible mechanism for the nitration of aniline derivatives via photoredox catalysis.
Scheme 17: Synthesis of carbazoles via intramolecular amination.
Figure 18: Proposed mechanism for the formation of carbazoles from biaryl derivatives.
Scheme 18: Synthesis of substituted phenols using QuCN.
Figure 19: Mechanism for the synthesis of phenol derivatives with photoredox catalyst 8.
Scheme 19: Synthesis of substituted phenols with DDQ (5).
Figure 20: Possible mechanism for the generation of phenols with the aid of photoredox catalyst 5.
Scheme 20: Aerobic bromination of arenes using an acridinium-based photocatalyst.
Scheme 21: Aerobic bromination of arenes with anthraquinone.
Figure 21: Proposed mechanism for the synthesis of monobrominated compounds.
Scheme 22: Chlorination of benzene derivatives with Mes-Acr-MeClO4 (2).
Figure 22: Mechanism for the synthesis of 131 from 132.
Scheme 23: Chlorination of arenes with 4CzIPN (5a).
Figure 23: Plausible mechanism for the oxidative photocatalytic monochlorination using 5a.
Scheme 24: Monofluorination using QuCN-ClO4 (8).
Scheme 25: Fluorination with fluorine-18.
Scheme 26: Aerobic amination with acridinium catalyst 3a.
Figure 24: Plausible mechanism for the aerobic amination using acridinium catalyst 3a.
Scheme 27: Aerobic aminations with semiconductor photoredox catalyst 18.
Scheme 28: Perfluoroalkylation of arenes.
Scheme 29: Synthesis of benzonitriles in the presence of 3a.
Figure 25: Plausible mechanism for the synthesis of substituted benzonitrile derivatives in the presence of 3a....
Beilstein J. Org. Chem. 2020, 16, 212–232, doi:10.3762/bjoc.16.24
Graphical Abstract
Scheme 1: Competitive side reactions in the Cu ECA of organometallic reagents to α,β-unsaturated aldehydes.
Scheme 2: Cu-catalyzed ECA of α,β-unsaturated aldehydes with phosphoramidite- (a) and phosphine-based ligands...
Scheme 3: One-pot Cu-catalyzed ECA/organocatalyzed α-substitution of enals.
Scheme 4: Combination of copper and amino catalysis for enantioselective β-functionalizations of enals.
Scheme 5: Optimized conditions for the Cu ECAs of R2Zn, RMgBr, and AlMe3 with α,β-unsaturated aldehydes.
Scheme 6: CuECA of Grignard reagents to α,β-unsaturated thioesters and their application in the asymmetric to...
Scheme 7: Improved Cu ECA of Grignard reagents to α,β-unsaturated thioesters, and their application in the as...
Scheme 8: Catalytic enantioselective synthesis of vicinal dialkyl arrays via Cu ECA of Grignard reagents to γ...
Scheme 9: 1,6-Cu ECA of MeMgBr to α,β,γ,δ-bisunsaturated thioesters: an iterative approach to deoxypropionate...
Scheme 10: Tandem Cu ECA/intramolecular enolate trapping involving 4-chloro-α,β-unsaturated thioester 22.
Scheme 11: Cu ECA of Grignard reagents to 3-boronyl α,β-unsaturated thioesters.
Scheme 12: Cu ECA of alkylzirconium reagents to α,β-unsaturated thioesters.
Scheme 13: Conversion of acylimidazoles into aldehydes, ketones, acids, esters, amides, and amines.
Scheme 14: Cu ECA of dimethyl malonate to α,β-unsaturated acylimidazole 31 with triazacyclophane-based ligand ...
Scheme 15: Cu/L13-catalyzed ECA of alkylboranes to α,β-unsaturated acylimidazoles.
Scheme 16: Cu/hydroxyalkyl-NHC-catalyzed ECA of dimethylzinc to α,β-unsaturated acylimidazoles.
Scheme 17: Stereocontrolled synthesis of 3,5,7-all-syn and anti,anti-stereotriads via iterative Cu ECAs.
Scheme 18: Stereocontrolled synthesis of anti,syn- and anti,anti-3,5,7-(Me,OR,Me) units via iterative Cu ECA/B...
Scheme 19: Cu-catalyzed ECA of dialkylzinc reagents to α,β-unsaturated N-acyloxazolidinones.
Scheme 20: Cu/phosphoramidite L16-catalyzed ECA of dialkylzincs to α,β-unsaturated N-acyl-2-pyrrolidinones.
Scheme 21: Cu/(R,S)-Josiphos (L9)-catalyzed ECA of Grignard reagents to α,β-unsaturated amides.
Scheme 22: Cu/Josiphos (L9)-catalyzed ECA of Grignard reagents to polyunsaturated amides.
Scheme 23: Cu-catalyzed ECA of trimethylaluminium to N-acylpyrrole derivatives.
Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218
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.
Beilstein J. Org. Chem. 2018, 14, 2838–2845, doi:10.3762/bjoc.14.262
Graphical Abstract
Scheme 1: Pd-catalyzed C(sp2)–P couplings at C-2 or C-4 in the 13α-estrone series.
Beilstein J. Org. Chem. 2018, 14, 2156–2162, doi:10.3762/bjoc.14.189
Graphical Abstract
Figure 1: Structures of GMIIb inhibitors.
Scheme 1: Synthesis of pyrrolidines 2a and 3a.
Scheme 2: Synthesis of pyrrolidines 2b,c and 3b,c.
Scheme 3: Synthesis of pyrrolidines 4.
Scheme 4: Synthesis of pyrrolidines 5.
Figure 2: Molecular structure (OLEX2 drawing with adjacent ChemDraw image) of compound 20. Atomic displacemen...
Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138
Graphical Abstract
Scheme 1: Left: The Mitsunobu reaction is essentially a nucleophilic substitution of alcohols occurring with ...
Scheme 2: Mechanistic considerations on the Mitsunobu reaction with carbohydrate hemiacetals (depicted in sim...
Scheme 3: Anomeric esterification using the Mitsunobu procedure [29].
Scheme 4: Conversion of allyl glucuronate into various 1-O-esterified allyl glucuronates using anomeric Mitsu...
Scheme 5: Synthesis of anomeric glycosyl esters as substrates for Au-catalyzed glycosylation [40].
Scheme 6: Correlation between pKa value of the employed acids (or alcohol) and the favoured anomeric configur...
Scheme 7: Synthesis of the β-mannosyl phosphates for the synthesis of HBP 43 by anomeric phosphorylation acco...
Scheme 8: Synthesis of phenyl glycosides 44 and 45 from unprotected sugars [24].
Scheme 9: Synthesis of azobenzene mannosides 47 and 48 without protecting group chemistry [46].
Scheme 10: Synthesis of various aryl sialosides using Mitsunobu glycosylation [25].
Scheme 11: Mitsunobu synthesis of different jadomycins [54,55]. BOM: benzyloxymethyl.
Scheme 12: Stereoselectivity in the Mitsunobu synthesis of catechol glycosides in the gluco- and manno-series [56]....
Scheme 13: Formation of a 1,2-cis glycoside 80 assisted by steric hindrance of the β-face of the disaccharide ...
Scheme 14: Stereoselective β-D-mannoside synthesis [60].
Scheme 15: TIPS-assisted synthesis of 1,2-cis arabinofuranosides [63]. TIPS: triisopropylsilyl.
Scheme 16: The Mitsunobu reaction with glycals leads to interesting rearrangement products [69].
Scheme 17: Synthesis of disaccharides using mercury(II) bromide as co-activator in the Mitsunobu reaction [75].
Scheme 18: Synthesis of various fructofuranosides according to Mitsunobu and proposed neighbouring group parti...
Scheme 19: The Mitsunobu reaction allows stereoslective acetalization of dihydroartemisinin [77].
Scheme 20: Synthesis of alkyl thioglycosides by Mitsunobu reaction [81].
Scheme 21: Preparation of iminoglycosylphthalimide 115 from 114 [85].
Scheme 22: Mitsunobu reaction as a key step in the total synthesis of aurantoside G [87].
Scheme 23: Utilization of an N–H acid in the Mitsunobu reaction [88].
Scheme 24: Mitsunobu reaction with 1H-tetrazole [89].
Scheme 25: Formation of a rebeccamycin analogue using the Mitsunobu reaction [101].
Scheme 26: Synthesis of carbohydrates with an alkoxyamine bond [114].
Scheme 27: Synthesis of glycosyl fluorides and glycosyl azides according to Mitsunobu [118,119].
Scheme 28: Anomeric oxidation under Mitsunobu conditions [122].
Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98
Graphical Abstract
Scheme 1: Tropone (1), tropolone (2) and their resonance structures.
Figure 1: Natural products containing a tropone nucleus.
Figure 2: Possible isomers 11–13 of benzotropone.
Scheme 2: Synthesis of benzotropones 11 and 12.
Scheme 3: Oxidation products of benzotropylium fluoroborate (16).
Scheme 4: Oxidation of 7-bromo-5H-benzo[7]annulene (22).
Scheme 5: Synthesis of 4,5-benzotropone (11) using o-phthalaldehyde (27).
Scheme 6: Synthesis of 4,5-benzotropone (11) starting from oxobenzonorbornadiene 31.
Scheme 7: Acid-catalyzed cleavage of oxo-bridge of 34.
Scheme 8: Synthesis of 4,5-benzotropone (11) from o-xylylene dibromide (38).
Scheme 9: Synthesis of 4,5-benzotropone (11) via the carbene adduct 41.
Scheme 10: Heck coupling strategy for the synthesis of 11.
Scheme 11: Synthesis of benzofulvalenes via carbonyl group of 4,5-benzotropone (11).
Figure 3: Some cycloheptatrienylium cations.
Scheme 12: Synthesis of condensation product 63 and its subsequent oxidative cyclization products.
Figure 4: A novel series of benzo[7]annulenes prepared from 4,5-benzotropone (11).
Scheme 13: Preparation of substituted benzo[7]annulene 72 using the Mukaiyama-Michael reaction.
Figure 5: Possible benzo[7]annulenylidenes 73–75.
Scheme 14: Thermal and photochemical decomposition of 7-diazo-7H-benzo[7]annulene (76) and the trapping of int...
Scheme 15: Synthesis of benzoheptafulvalene 86.
Scheme 16: Synthesis of 7-(diphenylmethylene)-7H-benzo[7]annulene (89).
Scheme 17: Reaction of 4,5-benzotropone (11) with dimethyl diazomethane.
Scheme 18: Synthesis of dihydrobenzomethoxyazocine 103.
Scheme 19: Synthesis and reducibility of benzo-homo-2-methoxyazocines.
Scheme 20: Synthesis of 4,5-benzohomotropones 104 and 115 from 4,5-benzotropones 11 and 113.
Scheme 21: A catalytic deuterogenation of 4,5-benzotropone (11) and synthesis of 5-monosubstituted benzo[7]ann...
Scheme 22: Synthesis of methyl benzo[7]annulenes 131 and 132.
Scheme 23: Ambident reactivity of halobenzo[7]annulenylium cations 133a/b.
Scheme 24: Preparation of benzo[7]annulenylidene–iron complexes 147.
Scheme 25: Synthesis of 1-ethynylbenzotropone (150) and the etheric compound 152 from 4,5-benzotropone (11) wi...
Scheme 26: Thermal decomposition of 4,5-benzotropone (11).
Scheme 27: Reaction of 4,5-benzotropone (11) with 1,2-ethanediol and 1,2-ethanedithiol.
Scheme 28: Conversions of 1-benzosuberone (162) to 2,3-benzotropone (12).
Scheme 29: Synthesis strategies for 2,3-bezotropone (12) using 1-benzosuberones.
Scheme 30: Oxidation-based synthesis of 2,3-benzotropone (12) via 1-benzosuberone (162).
Scheme 31: Synthesis of 2,3-benzotropone (12) from α-tetralone (171) via ring-expansion.
Scheme 32: Preparation of 2,3-benzotropone (12) by using of benzotropolone 174.
Figure 6: Benzoheptafulvenes as condensation products of 2,3-benzotropone (12).
Scheme 33: Conversion of 2,3-benzotropone (12) to tosylhydrazone salt 182 and gem-dichloride 187.
Figure 7: Benzohomoazocines 191–193 and benzoazocines 194–197.
Scheme 34: From 2,3-benzotropone (12) to carbonium ions 198–201.
Scheme 35: Cycloaddition reactions of 2,3-benzotropone (12).
Scheme 36: Reaction of 2,3-benzotropone (12) with various reagents and compounds.
Figure 8: 3,4-Benzotropone (13) and its resonance structure.
Scheme 37: Synthesis of 6,7-benzobicyclo[3.2.0]hepta-3,6-dien-2-one (230).
Figure 9: Photolysis and thermolysis products of 230.
Figure 10: Benzotropolones and their tautomeric structures.
Scheme 38: Synthesis strategies of 4,5-benzotropolone (238).
Scheme 39: Synthesis protocol for 2-hydroxy-4,5-benzotropone (238) using oxazole-benzo[7]annulene 247.
Figure 11: Some quinoxaline and pyrazine derivatives 254–256 prepared from 4,5-benzotropolone (238).
Scheme 40: Nitration product of 4,5-benzotropolone (238) and its isomerization to 1-nitro-naphthoic acid (259)....
Scheme 41: Synthesis protocol for 6-hydroxy-2,3-benzotropone (239) from benzosuberone (162).
Scheme 42: Various reactions via 6-hydroxy-2,3-benzotropone (239).
Scheme 43: Photoreaction of 6-hydroxy-2,3-benzotropone (239).
Scheme 44: Synthesis of 7-hydroxy-2,3-benzotropone (241) from benzosuberone (162).
Scheme 45: Synthesis strategy for 7-hydroxy-2,3-benzotropone (241) from ketone 276.
Scheme 46: Synthesis of 7-hydroxy-2,3-benzotropone (241) from β-naphthoquinone (280).
Scheme 47: Synthesis of 7-hydroxy-2,3-benzotropone (241) from bicyclic endoperoxide 213.
Scheme 48: Synthesis of 7-hydroxy-2,3-benzotropone (241) by ring-closing metathesis.
Figure 12: Various monosubstitution products 289–291 of 7-hydroxy-2,3-benzotropone (241).
Scheme 49: Reaction of 7-hydroxy-2,3-benzotropone (241) with various reagents.
Scheme 50: Synthesis of 4-hydroxy-2,3-benzotropones 174 and 304 from diketones 300/301.
Scheme 51: Catalytic hydrogenation of diketones 300 and 174.
Scheme 52: Synthesis of halo-benzotropones from alkoxy-naphthalenes 306, 307 and 310.
Figure 13: Unexpected byproducts 313–315 during synthesis of chlorobenzotropone 309.
Figure 14: Some halobenzotropones and their cycloadducts.
Scheme 53: Multisep synthesis of 2-chlorobenzotropone 309.
Scheme 54: A multistep synthesis of 2-bromo-benzotropone 26.
Scheme 55: A multistep synthesis of bromo-2,3-benzotropones 311 and 316.
Scheme 56: Oxidation reactions of 8-bromo-5H-benzo[7]annulene (329) with some oxidants.
Scheme 57: Synthesis of 2-bromo-4,5-benzotropone (26).
Scheme 58: Synthesis of 6-chloro-2,3-benzotropone (335) using LiCl and proposed intermediate 336.
Scheme 59: Reaction of 7-bromo-2,3-benzotropone (316) with methylamine.
Scheme 60: Reactions of bromo-2,3-benzotropones 26 and 311 with dimethylamine.
Scheme 61: Reactions of bromobenzotropones 311 and 26 with NaOMe.
Scheme 62: Reactions of bromobenzotropones 26 and 312 with t-BuOK in the presence of DPIBF.
Scheme 63: Cobalt-catalyzed reductive cross-couplings of 7-bromo-2,3-benzotropone (316) with cyclic α-bromo en...
Figure 15: Cycloadduct 357 and its di-π-methane rearrangement product 358.
Scheme 64: Catalytic hydrogenation of 2-chloro-4,5-benzotropone (311).
Scheme 65: Synthesis of dibromo-benzotropones from benzotropones.
Scheme 66: Bromination/dehydrobromination of benzosuberone (162).
Scheme 67: Some transformations of isomeric dibromo-benzotropones 261A/B.
Scheme 68: Transformations of benzotropolone 239B to halobenzotropolones 369–371.
Figure 16: Bromobenzotropolones 372–376 and 290 prepared via bromination/dehydrobromination strategy.
Scheme 69: Synthesis of some halobenzotropolones 289, 377 and 378.
Figure 17: Bromo-chloro-derivatives 379–381 prepared via chlorination.
Scheme 70: Synthesis of 7-iodo-3,4-benzotropolone (382).
Scheme 71: Hydrogenation of bromobenzotropolones 369 and 370.
Scheme 72: Debromination reactions of mono- and dibromides 290 and 375.
Figure 18: Nitratation and oxidation products of some halobenzotropolenes.
Scheme 73: Azo-coupling reactions of some halobenzotropolones 294, 375 and 378.
Figure 19: Four possible isomers of dibenzotropones 396–399.
Figure 20: Resonance structures of tribenzotropone (400).
Scheme 74: Two synthetic pathways for tribenzotropone (400).
Scheme 75: Synthesis of tribenzotropone (400) from dibenzotropone 399.
Scheme 76: Synthesis of tribenzotropone (400) from 9,10-phenanthraquinone (406).
Scheme 77: Synthesis of tribenzotropone (400) from trifluoromethyl-substituted arene 411.
Figure 21: Dibenzosuberone (414).
Figure 22: Reduction products 415 and 416 of tribenzotropone (400).
Figure 23: Structures of tribenzotropone dimethyl ketal 417 and 4-phenylfluorenone (412) and proposed intermed...
Figure 24: Structures of benzylidene- and methylene-9H-tribenzo[a,c,e][7]annulenes 419 and 420 and chiral phos...
Figure 25: Structures of tetracyclic alcohol 422, p-quinone methide 423 and cation 424.
Figure 26: Structures of host molecules 425–427.
Scheme 78: Synthesis of non-helical overcrowded derivatives syn/anti-431.
Figure 27: Hexabenzooctalene 432.
Figure 28: Structures of possible eight isomers 433–440 of naphthotropone.
Scheme 79: Synthesis of naphthotropone 437 starting from 1-phenylcycloheptene (441).
Scheme 80: Synthesis of 10-hydroxy-11H-cyclohepta[a]naphthalen-11-one (448) from diester 445.
Scheme 81: Synthesis of naphthotropone 433.
Scheme 82: Synthesis of naphthotropones 433 and 434 via cycloaddition reaction.
Scheme 83: Synthesis of naphthotropone 434 starting from 452.
Figure 29: Structures of tricarbonyl(tropone)irons 458, and possible cycloadducts 459.
Scheme 84: Synthesis of naphthotropone 436.
Scheme 85: Synthesis of precursor 465 for naphthotropone 435.
Scheme 86: Generation of naphthotropone 435 from 465.
Figure 30: Structures of tropylium cations 469 and 470.
Figure 31: Structures of tropylium ions 471+.BF4−, 472+.BF4−, and 473+.BF4−.
Scheme 87: Synthesis of tropylium ions 471+.BF4− and 479+.ClO4−.
Scheme 88: Synthesis of 1- and 2-methylanthracene (481 and 482) via carbene–carbene rearrangement.
Figure 32: Trapping products 488–490.
Scheme 89: Generation and chemistry of a naphthoannelated cycloheptatrienylidene-cycloheptatetraene intermedia...
Scheme 90: Proposed intermediates and reaction pathways for adduct 498.
Scheme 91: Exited-state intramolecular proton transfer of 505.
Figure 33: Benzoditropones 506 and 507.
Scheme 92: Synthesis of benzoditropone 506e.
Scheme 93: Synthetic approaches for dibenzotropone 507 via tropone (1).
Scheme 94: Formation mechanisms of benzoditropone 507 and 516 via 515.
Scheme 95: Synthesis of benzoditropones 525 and 526 from pyromellitic dianhydride (527).
Figure 34: Possible three benzocyclobutatropones 534–536.
Scheme 96: Synthesis of benzocyclobutatropones 534 and 539.
Scheme 97: Synthesis attempts for benzocyclobutatropone 545.
Scheme 98: Generation and trapping of symmetric benzocyclobutatropone 536.
Scheme 99: Synthesis of chloro-benzocyclobutatropone 552 and proposed mechanism of fluorenone derivatives.
Scheme 100: Synthesis of tropolone analogue 559.
Scheme 101: Synthesis of tropolones 561 and 562.
Figure 35: o/p-Tropoquinone rings (563 and 564) and benzotropoquinones (565–567).
Scheme 102: Synthesis of benzotropoquinone 566.
Scheme 103: Synthesis of benzotropoquinone 567 via a Diels–Alder reaction.
Figure 36: Products 575–577 through 1,2,3-benzotropoquinone hydrate 569.
Scheme 104: Structures 578–582 prepared from tropoquinone 567.
Figure 37: Two possible structures 583 and 584 for dibenzotropoquinone, and precursor compound 585 for 583.
Scheme 105: Synthesis of saddle-shaped ketone 592 using dibenzotropoquinone 584.
Beilstein J. Org. Chem. 2018, 14, 1103–1111, doi:10.3762/bjoc.14.96
Graphical Abstract
Figure 1: Halogenated terpenoids from natural sources.
Scheme 1: Previously developed bromo-functionalizations of polyprenoids using iodine(III) reagents.
Figure 2: Selected monoterpenoids used in this study.
Scheme 2: Dibromination of acyclic monoterpenoids.
Scheme 3: Bromo(trifluoro)acetoxylation of acyclic monoterpenoids.
Scheme 4: Bromohydroxylation of acyclic monoterpenoids.
Scheme 5: Iodo(trifluoro)acetoxylation of acyclic monoterpenoids.
Scheme 6: Chlorination of acyclic monoterpenoids.
Scheme 7: General mechanism proposal for the formation of 2–6 and control experiments.
Beilstein J. Org. Chem. 2018, 14, 430–435, doi:10.3762/bjoc.14.31
Graphical Abstract
Scheme 1: The influence of the milling frequency on the reaction of 1a with NIS.
Scheme 2: Palladium-catalyzed ortho-iodination of 1a in toluene.
Scheme 3: Plausible mechanism.
Scheme 4: Palladium-catalyzed ortho-bromination and chlorination of 1a in a ball mill.
Beilstein J. Org. Chem. 2017, 13, 2915–2921, doi:10.3762/bjoc.13.284
Graphical Abstract
Scheme 1: Relative reactivity of α-fluoroacetophenone to α-chloroacetophenone and α-bromoacetophenone.
Scheme 2: Competitive reduction of haloacetophenones and acetophenone.
Figure 1: Conformational energy profiles of halogenated acetophenones (a) in gas phase; (b) in EtOH; (c) over...
Figure 2: Optimised gas phase geometries of (a) α-fluoroacetophenone and (b) α-chloroacetophenone emphasising...
Figure 3: Most stable conformations of (a) α-fluoroacetophenone and (b) α-chloroacetophenone in ethanol.
Figure 4: Expected reactive conformation of halo-acetophenones.
Figure 5: Orbital interactions in gauche- and cis-conformations of haloacetophenones.
Figure 6: Variation of dipole moment with angle for haloacetophenones.
Figure 7: Highest energy conformation of fluoroacetophenone, emphasizing the closeness of approach of fluorin...
Scheme 3: Competitive reduction of fluoroacetone and chloroacetone.
Figure 8: Conformational energy profiles of halogenated acetones in gas phase and in MeOH.
Figure 9: Overlay of conformational energy profiles of fluoroacetone and fluoroacetophenone.
Beilstein J. Org. Chem. 2017, 13, 2739–2750, doi:10.3762/bjoc.13.270
Graphical Abstract
Scheme 1: Two different intermolecular cyclization pathways controlled by reagents used.
Scheme 2: Scope of reaction. Reaction conditions: 1 (1.2 mmol), 2 (1.0 mmol), KOt-Bu (2 mmol), in 3 mL CBrCl3...
Scheme 3: Scope of the reaction. Reaction conditions: 1 (1.0 mmol), 2 (1.5 mmol), In(OTf)3 (0.1 mmol), in 1.5...
Scheme 4: Control experiments.
Figure 1: Proposed mechanism (benzo[d]imidazo[2,1-b]thiazoles).
Figure 2: Proposed mechanism (benzo[4,5]thiazolo[3,2-a]pyrimidin-4-ones).
Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186
Graphical Abstract
Scheme 1: Mechanochemical aldol condensation reactions [48].
Scheme 2: Enantioselective organocatalyzed aldol reactions under mechanomilling. a) Based on binam-(S)-prolin...
Scheme 3: Mechanochemical Michael reaction [51].
Scheme 4: Mechanochemical organocatalytic asymmetric Michael reaction [52].
Scheme 5: Mechanochemical Morita–Baylis–Hillman (MBH) reaction [53].
Scheme 6: Mechanochemical Wittig reactions [55].
Scheme 7: Mechanochemical Suzuki reaction [56].
Scheme 8: Mechanochemical Suzuki–Miyaura coupling by LAG [57].
Scheme 9: Mechanochemical Heck reaction [59].
Scheme 10: a) Sonogashira coupling under milling conditions. b) The representative example of a double Sonogas...
Scheme 11: Copper-catalyzed CDC reaction under mechanomilling [67].
Scheme 12: Asymmetric alkynylation of prochiral sp3 C–H bonds via CDC [68].
Scheme 13: Fe(III)-catalyzed CDC coupling of 3-benzylindoles [69].
Scheme 14: Mechanochemical synthesis of 3-vinylindoles and β,β-diindolylpropionates [70].
Scheme 15: Mechanochemical C–N bond construction using anilines and arylboronic acids [78].
Scheme 16: Mechanochemical amidation reaction from aromatic aldehydes and N-chloramine [79].
Scheme 17: Mechanochemical CDC between benzaldehydes and benzyl amines [81].
Scheme 18: Mechanochemical protection of -NH2 and -COOH group of amino acids [85].
Scheme 19: Mechanochemical Ritter reaction [87].
Scheme 20: Mechanochemical synthesis of dialkyl carbonates [90].
Scheme 21: Mechanochemical transesterification reaction using basic Al2O3 [91].
Scheme 22: Mechanochemical carbamate synthesis [92].
Scheme 23: Mechanochemical bromination reaction using NaBr and oxone [96].
Scheme 24: Mechanochemical aryl halogenation reactions using NaX and oxone [97].
Scheme 25: Mechanochemical halogenation reaction of electron-rich arenes [88,98].
Scheme 26: Mechanochemical aryl halogenation reaction using trihaloisocyanuric acids [100].
Scheme 27: Mechanochemical fluorination reaction by LAG method [102].
Scheme 28: Mechanochemical Ugi reaction [116].
Scheme 29: Mechanochemical Passerine reaction [116].
Scheme 30: Mechanochemical synthesis of α-aminonitriles [120].
Scheme 31: Mechanochemical Hantzsch pyrrole synthesis [121].
Scheme 32: Mechanochemical Biginelli reaction by subcomponent synthesis approach [133].
Scheme 33: Mechanochemical asymmetric multicomponent reaction[134].
Scheme 34: Mechanochemical Paal–Knorr pyrrole synthesis [142].
Scheme 35: Mechanochemical synthesis of benzothiazole using ZnO nano particles [146].
Scheme 36: Mechanochemical synthesis of 1,2-di-substituted benzimidazoles [149].
Scheme 37: Mechanochemical click reaction using an alumina-supported Cu-catalyst [152].
Scheme 38: Mechanochemical click reaction using copper vial [155].
Scheme 39: Mechanochemical indole synthesis [157].
Scheme 40: Mechanochemical synthesis of chromene [158].
Scheme 41: Mechanochemical synthesis of azacenes [169].
Scheme 42: Mechanochemical oxidative C-P bond formation [170].
Scheme 43: Mechanochemical C–chalcogen bond formation [171].
Scheme 44: Solvent-free synthesis of an organometallic complex.
Scheme 45: Selective examples of mechano-synthesis of organometallic complexes. a) Halogenation reaction of Re...
Scheme 46: Mechanochemical activation of C–H bond of unsymmetrical azobenzene [178].
Scheme 47: Mechanochemical synthesis of organometallic pincer complex [179].
Scheme 48: Mechanochemical synthesis of tris(allyl)aluminum complex [180].
Scheme 49: Mechanochemical Ru-catalyzed olefin metathesis reaction [181].
Scheme 50: Rhodium(III)-catalyzed C–H bond functionalization under mechanochemical conditions [182].
Scheme 51: Mechanochemical Csp2–H bond amidation using Ir(III) catalyst [183].
Scheme 52: Mechanochemical Rh-catalyzed Csp2–X bond formation [184].
Scheme 53: Mechanochemical Pd-catalyzed C–H activation [185].
Scheme 54: Mechanochemical Csp2–H bond amidation using Rh catalyst.
Scheme 55: Mechanochemical synthesis of indoles using Rh catalyst [187].
Scheme 56: Mizoroki–Heck reaction of aminoacrylates with aryl halide in a ball-mill [58].
Scheme 57: IBX under mechanomilling conditions [8].
Scheme 58: Thiocarbamoylation of anilines; trapping of reactive aryl-N-thiocarbamoylbenzotriazole intermediate...
Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170
Graphical Abstract
Scheme 1: Generally accepted ion-pairing mechanism between the chiral cation Q+ of a PTC and an enolate and s...
Scheme 2: Reported asymmetric α-fluorination of β-ketoesters 1 using different chiral PTCs.
Scheme 3: Asymmetric α-fluorination of benzofuranones 4 with phosphonium salt PTC F1.
Scheme 4: Asymmetric α-fluorination of 1 with chiral phosphate-based catalysts.
Scheme 5: Anionic PTC-catalysed α-fluorination of enamines 7 and ketones 10.
Scheme 6: PTC-catalysed α-chlorination reactions of β-ketoesters 1.
Scheme 7: Shioiri’s seminal report of the asymmetric α-hydroxylation of 15 with chiral ammonium salt PTCs.
Scheme 8: Asymmetric ammonium salt-catalysed α-hydroxylation using oxygen together with a P(III)-based reduct...
Scheme 9: Asymmetric ammonium salt-catalysed α-photooxygenations.
Scheme 10: Asymmetric ammonium salt-catalysed α-hydroxylations using organic oxygen-transfer reagents.
Scheme 11: Asymmetric triazolium salt-catalysed α-hydroxylation with in situ generated peroxy imidic acid 24.
Scheme 12: Phase-transfer-catalysed dearomatization of phenols and naphthols.
Scheme 13: Ishihara’s ammonium salt-catalysed oxidative cycloetherification.
Scheme 14: Chiral phase-transfer-catalysed α-sulfanylation reactions.
Scheme 15: Chiral phase-transfer-catalysed α-trifluoromethylthiolation of β-ketoesters 1.
Scheme 16: Chiral phase-transfer-catalysed α-amination of β-ketoesters 1 using diazocarboxylates 38.
Scheme 17: Asymmetric α-fluorination of benzofuranones 4 using diazocarboxylates 38 in the presence of phospho...
Scheme 18: Anionic phase-transfer-catalysed α-amination of β-ketoesters 1 with aryldiazonium salts 41.
Scheme 19: Triazolium salt L-catalysed α-amination of different prochiral nucleophiles with in situ activated ...
Scheme 20: Phase-transfer-catalysed Neber rearrangement.
Beilstein J. Org. Chem. 2017, 13, 1518–1523, doi:10.3762/bjoc.13.151
Graphical Abstract
Figure 1: Brominating reagents.
Scheme 1: Optimization of the substituents of the amide group. Reactions were run using 1 (0.1 mmol), 3a (0.0...
Scheme 2: Substrate scope. Reactions were run using 1 (0.1 mmol), 3a (0.01 mmol), and 4a (0.3 mmol) in EtOAc ...
Scheme 3: Reactions of substrates with substituted phenols.
Scheme 4: Reactions of monobrominated substrates.
Scheme 5: Rotational barriers of substrates and intermediates calculated at the B3YLP/6-31G(d) level of theor...
Scheme 6: Reaction of substrate with protected phenol.
Beilstein J. Org. Chem. 2017, 13, 895–902, doi:10.3762/bjoc.13.90
Graphical Abstract
Scheme 1: Envisaged general approach for the synthesis of the title compounds.
Scheme 2: Synthesis of 4-iodopyrazoles of type 3.
Scheme 3: Lithium–halogen exchange and subsequent carboxylation with iodopyrazoles 3a–d.
Scheme 4: Attempted cross-coupling reactions with 4-halopyrazoles 5 and 3a.
Scheme 5: Negishi couplings with 4-iodopyrazoles 3a,b.
Scheme 6: Formation of pyrazoloquinolizin-6-ium iodide 12 upon reaction of 3a with (phenylethynyl)zinc bromid...
Scheme 7: Prototropic tautomerism of compound 1a.
Figure 1: 1H NMR (in italics), 13C NMR and 15N NMR (in bold) chemical shifts of compound 9a (in CDCl3).
Beilstein J. Org. Chem. 2016, 12, 2898–2905, doi:10.3762/bjoc.12.289
Graphical Abstract
Scheme 1: Access to enantiopure 3,6-dihydro-1,2-oxazines 3 via lithiated alkoxyallenes 1 and carbohydrate-der...
Scheme 2: Iodination of 1,2-oxazines syn-3a–c and anti-3a,d leading to 5-iodo-substituted 1,2-oxazines syn-4a...
Scheme 3: Sonogashira reactions of 4-methoxy-1,2-oxazines syn-4a, anti-4a and anti-4d leading to 5-alkynyl-su...
Scheme 4: Sonogashira reactions of D-glyceraldehyde-derived 1,2-oxazines syn-4a–c leading to 5-alkynyl-substi...
Scheme 5: Heck reactions of 1,2-oxazine syn-4a leading to 5-alkenyl-substituted 1,2-oxazines syn-13, syn-14 a...
Scheme 6: Suzuki–Miyaura reactions of 1,2-oxazines syn-4a, syn-4b and anti-4d leading to 5-styryl-substituted...
Scheme 7: Cross-coupling reaction of 1,2-oxazine anti-4d leading to 5-cyano-substituted 1,2-oxazine anti-25.
Scheme 8: Desilylation of 1,2-oxazine syn-5 and subsequent click reaction with benzyl azide leading to 5-(1,2...
Scheme 9: Hydrogenation of 1,2-oxazine syn-21 leading to γ-amino alcohols 27a,b and subsequent ring closure t...
Scheme 10: Hydrogenation of 1,2-oxazine anti-24 to products anti-29 and anti-30.
Beilstein J. Org. Chem. 2016, 12, 2325–2342, doi:10.3762/bjoc.12.226
Graphical Abstract
Figure 1: Structures of the enduracididine family of amino acids (1–6).
Figure 2: Enduracidin A (7) and B (8).
Figure 3: Minosaminomycin (9) and related antibiotic kasugamycin (10).
Figure 4: Enduracididine-containing compound 11 identified in a cytotoxic extract of Leptoclinides dubius [32].
Figure 5: Mannopeptimycins α–ε (12–16).
Figure 6: Regions of the mannopeptimycin structure investigated in structure–activity relationship investigat...
Figure 7: Teixobactin (17).
Scheme 1: Proposed biosynthesis of L-enduracididine (1) and L-β-hydroxyenduracididine (5).
Scheme 2: Synthesis of enduracididine (1) by Shiba et al.
Scheme 3: Synthesis of protected enduracididine diastereomers 31 and 32.
Scheme 4: Synthesis of the C-2 azido diastereomers 36 and 37.
Scheme 5: Synthesis of 2-azido-β-hydroxyenduracididine derivatives 38 and 39.
Scheme 6: Synthesis of protected β-hydroxyenduracididine derivatives 40 and 41.
Scheme 7: Synthesis of C-2 diastereomeric amino acids 46 and 47.
Scheme 8: Synthesis of protected β-hydroxyenduracididines 51 and 52.
Scheme 9: General transformation of alkenes to cyclic sulfonamide 54 via aziridine intermediate 53.
Scheme 10: Synthesis of (±)-enduracididine (1) and (±)-allo-enduracididine (3).
Scheme 11: Synthesis of L-allo-enduracididine (3).
Scheme 12: Synthesis of protected L-allo-enduracididine 63.
Scheme 13: Synthesis of β-hydroxyenduracididine derivative 69.
Scheme 14: Synthesis of minosaminomycin (9).
Scheme 15: Retrosynthetic analysis of mannopeptimycin aglycone (77).
Scheme 16: Synthesis of protected amino acids 87 and 88.
Scheme 17: Synthesis of mannopeptimycin aglycone (77).
Scheme 18: Synthesis of N-mannosylation model guanidine 92 and attempted synthesis of benzyl protected mannosy...
Scheme 19: Synthesis of benzyl protected mannosyl D-β-hydroxyenduracididine 97.
Scheme 20: Synthesis of L-β-hydroxyenduracididine 98.
Scheme 21: Total synthesis of mannopeptimycin α (12) and β (13).
Scheme 22: Synthesis of protected L-allo-enduracididine 102.
Scheme 23: The solid phase synthesis of teixobactin (17).
Scheme 24: Retrosynthesis of the macrocyclic core 109 of teixobactin (17).
Scheme 25: Synthesis of macrocycle 117.
Beilstein J. Org. Chem. 2016, 12, 1577–1584, doi:10.3762/bjoc.12.153
Graphical Abstract
Scheme 1: The main synthetic approaches to alkylcyanobiphenyls.
Scheme 2: Para-cyanophenylation of substituted benzonitriles 2 by dianion 12− with the formation of a long-li...
Scheme 3: para-Cyanophenylation of 1-cyanonaphthalene 5i by dianion 12− with subsequent butylation providing ...
Beilstein J. Org. Chem. 2016, 12, 1361–1365, doi:10.3762/bjoc.12.129
Graphical Abstract
Scheme 1: Selective bromochlorination and possible disconnections for anverene (1).
Scheme 2: Selective total synthesis of (−)-anverene. Reagents and conditions: a) NBS (1.2 equiv), ClTi(OiPr)3...
Beilstein J. Org. Chem. 2016, 12, 1302–1308, doi:10.3762/bjoc.12.122
Graphical Abstract
Figure 1: Tetraphenylene and its saddle-shaped structure.
Scheme 1: The Pd(OAc)2-catalyzed reaction of nitriles with tetraphenylene (1).
Beilstein J. Org. Chem. 2016, 12, 1243–1249, doi:10.3762/bjoc.12.119
Graphical Abstract
Scheme 1: New synthetic strategy for THQs via PA-directed C−H functionalization.
Scheme 2: Preparation of iodo-substituted THQs via PA-directed C−H functionalization strategy. a) ArI (2 equi...
Scheme 3: Removal of PA auxiliary from THQ product.
Beilstein J. Org. Chem. 2016, 12, 1072–1078, doi:10.3762/bjoc.12.101
Graphical Abstract
Scheme 1: Selected benzothiadaiazine 1,1-dioxides with potent biological activities.
Scheme 2: Scope of acetophenones (reaction conditions: 1 (0.33 mmol), 2a (0.3 mmol), DMSO (2 mL), I2 (0.75 eq...
Scheme 3: Scope of 2-aminobenzenesulfonamides (reaction conditions: 1 (0.33 mmol), 2a (0.3 mmol), DMSO (2 mL)...
Scheme 4: Reactions of 2-aminobenzenesulfonamides bearing an alknyl group (reaction conditions: 1 (0.33 mmol)...
Scheme 5: Gram scale reaction between 1a and 2a.
Figure 1: X-ray crystal structure of 4b (CCDC 1444753).
Scheme 6: Control experiment.
Scheme 7: Proposed mechanism.
Beilstein J. Org. Chem. 2015, 11, 2132–2144, doi:10.3762/bjoc.11.230
Graphical Abstract
Scheme 1: Copper-catalyzed C–H bond halogenation of 2-arylpyridine.
Scheme 2: ortho-Chlorination of 2-arylpridines with acyl chlorides.
Scheme 3: Copper-catalyzed chlorination of 2-arylpyridines using LiCl.
Scheme 4: Copper-catalyzed C–H halogenation of 2-arylpyridines using LiX.
Scheme 5: Copper-mediated selective C–H halogenations of 2-arylpyridine.
Scheme 6: Copper-catalyzed C–H o-halogenation using removable DG.
Scheme 7: Copper-catalyzed C–H halogenations using PIP as DG.
Scheme 8: Copper-catalyzed quinoline C–H chlorination.
Scheme 9: Copper-catalyzed arene C–H fluorination of benzamides.
Scheme 10: Copper-catalyzed arene C–H iodination of 1,3-azoles.
Scheme 11: Copper-catalyzed C–H halogenations of phenols.
Scheme 12: Proposed mechanism for the C–H halogenation of phenols.
Scheme 13: Copper-catalyzed halogenation of electron enriched arenes.
Scheme 14: Copper-catalyzed C–H bromination of arenes.
Scheme 15: CuI-mediated synthesis of iododibenzo[b,d]furans via C–H functionalization.
Scheme 16: Cu-Mn spinel oxide-catalyzed phenol and heteroarene halogenation.
Scheme 17: Copper-catalyzed halogenations of 2-amino-1,3thiazoles.
Scheme 18: Copper-mediated chlorination and bromination of indolizines.
Scheme 19: Copper-catalyzed three-component synthesis of bromoindolizines.
Scheme 20: Copper-mediated C–H halogenation of azacalix[1]arene[3]pyridines.
Scheme 21: Copper-mediated cascade synthesis of halogenated pyrrolones.
Scheme 22: Copper-mediated alkene C–H chlorination in spirothienooxindole.
Scheme 23: Copper-catalyzed remote C–H chlorination of alkyl hydroperoxides.
Scheme 24: Copper-catalyzed C–H fluorination of alkanes.
Scheme 25: Copper-catalyzed or mediated C–H halogenations of active C(sp3)-bonds.
Beilstein J. Org. Chem. 2015, 11, 1392–1397, doi:10.3762/bjoc.11.150
Graphical Abstract
Scheme 1: Synthesis of vinyl C-deoxyribosides α-2 and β-2.
Figure 1: Alkenes 3 used in cross-metathesis reactions with 2.
Scheme 2: Hydrogenation of β-4b–β-4d to β-5b–β-5d.
Scheme 3: Deprotection of β-4e and β-5b to β-6e and β-7b.
Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45
Graphical Abstract
Figure 1: Preferential sites of cholesterol electrooxidation.
Scheme 1: Functionalization of the cholesterol side chain.
Scheme 2: Oxidation of cholestane-3β,5α,6β-triol triacetate (3) with the Gif system.
Scheme 3: Electrochemical oxidation of cholesteryl acetate (1a) with dioxygen and iron–picolinate complexes.
Scheme 4: Electrochemical chlorination of cholesterol catalyzed by FeCl3.
Scheme 5: Electrochemical chlorination of Δ5-steroids.
Scheme 6: Electrochemical bromination of Δ5-steroids in different solvents.
Scheme 7: Direct electrochemical acetoxylation of cholesterol at the allylic position.
Scheme 8: Direct anodic oxidation of cholesterol in dichloromethane.
Scheme 9: A plausible mechanism of the electrochemical oxidation of cholesterol in dichloromethane.
Scheme 10: The electrochemical formation of glycosides and glycoconjugates.
Scheme 11: Efficient electrochemical oxidation of cholesterol to cholesta-4,6-dien-3-one (24).