The introduction of fluorine into organic molecules is widely practised particularly when tuning the properties of molecules for specialist functions. Fluorine substitution finds a prominent role in pharmaceutical development, in governing bioactivity in a wide range of agrochemical products, in soft materials chemistry such as liquid crystals, in photoresist polymers, self-assembling monolayers and in positron emission tomography. Allied to this breadth of activity is a steady development in the number and range of fluorination reagents and methods. This Thematic Series aims to provide an insight into these developments.
Graphical Abstract
Figure 1: Representative examples of bioactive imidazo[1,2-a]pyridines, imidazo[1,2-a]pyrimidines, imidazopyr...
Scheme 1: Retrosynthetic scheme for the preparation of our target molecules A.
Scheme 2: Synthesis of enones 6 with a gem-difluoroalkyl side chain.
Scheme 3: Synthesis of 7a.
Figure 2: Structures of 7a and 7e by X-ray crystallography analysis.
Scheme 4: One-pot synthesis of 7a.
Graphical Abstract
Scheme 1: Synthesis of trifluoroethoxy-substituted phthalocyanine.
Scheme 2: Synthesis of trifluoroethoxy-substituted binuclear phthalocyanine 5 in Solkane® 365 mfc.
Scheme 3: Synthesis of trifluoroethoxy-substituted unsymmetrical phthalocyanines.
Scheme 4: Synthesis of trifluoroethoxy-substituted phthalocyanine dimers linked at the β-position.
Figure 1: Structure of trifluoroethoxy-substituted phthalocyanine dimers linked at the α-position.
Figure 2: Structure of trifluoroethoxy-substituted dimer via a diacetylene linker.
Figure 3: UV–vis spectra of 9 (A) and 5 (B).
Figure 4: Structure of binuclear phthalocyanines linked by a triazole linker.
Figure 5: Structure of trinuclear phthalocyanines linked by a triazole linker, and windmill-like molecular st...
Scheme 5: Synthesis of trifluoroethoxy-substituted phthalocyanines conjugated with peptides.
Scheme 6: Synthesis of trifluoroethoxy-substituted phthalocyanines conjugated with deoxyribonucleosides.
Scheme 7: Synthesis of trifluoroethoxy-substituted phthalocyanines conjugated with cyclodextrin.
Figure 6: Direction of energy transfer of phthalocyanine–fullerene conjugates.
Scheme 8: Synthesis of fluoropolymer-bearing phthalocyanine side groups.
Scheme 9: Synthesis of trifluoroethoxy-substituted double-decker type phthalocyanines.
Scheme 10: Synthesis of trifluoroethoxy-substituted subphthalocyanine.
Figure 7: Structure of axial ligand substituted subphthalocyanine hybrid dyes.
Scheme 11: Synthesis of subphthalocyanine homodimers.
Scheme 12: Synthesis of subphthalocyanine heterodimers.
Figure 8: Energy transfer between subphthalocyanine units.
Figure 9: Structure of phthalocyanine and subphthalocyanine benzene-fused homodimers.
Scheme 13: Synthesis of a phthalocyanine and subphthalocyanine benzene-fused heterodimer.
Figure 10: X-ray crystallography of Pc-subPc (left) and UV–vis spectra of benzene-fused dimers.
Graphical Abstract
Scheme 1: Reagents and precursors used for trifluoromethylation reactions.
Scheme 2: Preparation of [(SIMes)2Cu][Cu(CF3)2].
Scheme 3: General protocol for reactions described in Figure 1.
Figure 1: Yields of 4-(trifluoromethyl)-1,1’-biphenyl over time for the systems described in Scheme 1. These runs rep...
Figure 2: Yields of 4-(trifluoromethyl)-1,1’-biphenyl over time for the systems described in Scheme 1. Conditions for ...
Figure 3: Reaction of 1-iodo-4-methylbenzene with systems A1, A2, and B2 to produce 1-methyl-4-(trifluorometh...
Figure 4: Reaction of 2-iodotoluene with systems A1, A2, and B2 to produce 1-methyl-2-(trifluoromethyl)benzen...
Graphical Abstract
Figure 1: Examples of conformationally biased amino acids [1-10]. Compound 6 is a target of this work.
Scheme 1: The first synthetic approach.
Scheme 2: The second synthetic approach.
Scheme 3: The third synthetic approach.
Scheme 4: The fourth synthetic approach (partially reproduced from ref. [17]).
Figure 2: Selected J values and the inferred molecular conformations of 6a and 6b.
Graphical Abstract
Scheme 1: Fluorination of diol derivative (±)-1.
Scheme 2: Fluorination of diol derivative (±)-4.
Figure 1: X-ray structure of fluorohydrine derivative (±)-5.
Scheme 3: Fluorination of diol derivative (±)-6.
Scheme 4: Fluorination of cyclohexane-derived diol (±)-8.
Scheme 5: Proposed route for the formation of compounds (±)-10 and (±)-11.
Scheme 6: Fluorination of diol derivative (±)-12.
Scheme 7: Fluorination of diol derivative (±)-14.
Scheme 8: Proposed route for the formation of compounds (±)-15, (±)-16 and (±)-17.
Scheme 9: Fluorination of N-Cbz-protected diol derivative (±)-18.
Scheme 10: Fluorination of diol derivative (±)-20.
Scheme 11: Fluorination of meso diol derivative 24.
Graphical Abstract
Figure 1: A. Dependence of the lipophilicity (logP) on the number of fluorine atoms in a partially fluorinate...
Scheme 1: Synthesis of the model compounds.
Figure 2: Kinetics of the C-terminal ester hydrolysis.
Figure 3: Partitioning of the esters 1–5 between octan-1-ol and water. Insert: comparison with the other part...
Scheme 2: Amide isomerism in the N-acetylprolyl fragment.
Figure 4: Enhancement of the trans/cis thermodynamic preferences in the ester models as a function of the sol...
Scheme 3: A. Four-state conformational equilibrium model used by Siebler et al. [72] for explanations of the elev...
Scheme 4: Elevation of the trans/cis ratio in derivatives of N-acyl proline may result from the enhanced n→π*...
Scheme 5: Synthesis of the model peptides.
Figure 5: Mean residue molar circular dichroism (Δε) of peptides 8–10 in methanol (left) and aqueous phosphat...
Figure 6: Conformational analysis of the peptides by 1H DOSY NMR (D2O, 298 K). The theoretical values were ca...
Figure 7: Hydrolysis of the C-terminal 2,2-difluoroethyl esters of the oligopeptides in buffered deuterium ox...
Graphical Abstract
Figure 1: Crystallographic analysis of the major diastereomer of 3a (some hydrogen atoms are omitted for clar...
Scheme 1: Explanation of the construction of the main stereoisomers.
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...
Graphical Abstract
Scheme 1: Synthetic routes for the preparation of trifluoromethyl dithiocarbamates.
Scheme 2: Synthesis of S-trifluoromethyl dithiocarbamates. Isolated yields are given in parentheses.
Scheme 3: Formation of benzyl isothiocyanate in a reaction with benzylamine.
Figure 1: Variable temperature 1H NMR spectra of compound 4c (CH2 region on the left and CH3 region on the ri...
Figure 2: The Eyring plot obtained for the rotation around the N–C bond in compound 4c.
Figure 3: The optimized structure of compound 4b (left) and the transition state structure for the rotation a...
Graphical Abstract
Scheme 1: Palladium-catalyzed Heck-type reaction of 2-bromo-1,1,1-trifluorohexane (2a) with alkenes 1. Reacti...
Scheme 2: Palladium-catalyzed Heck-type reaction of fluorinated secondary bromides (iodides) 2 with alkenes 1...
Scheme 3: Radical clock experiment for mechanistic studies.
Scheme 4: Proposed mechanism.
Graphical Abstract
Figure 1: Summary of the present study.
Scheme 1: Hydrogenation of compounds 4–6 and preparation of N1(3)-unsubstituted compounds 9–11d.
Figure 2: Molecular structure of compound 11b. Two enantiomers form a heterochiral dimer in the crystal state...
Graphical Abstract
Scheme 1: Electrophilic addition of 1a to alkynes. Yields shown are those of isolated products; yields determ...
Figure 1: Single-crystal X-ray structure of 3a.
Scheme 2: Mechanism proposal.
Scheme 3: Perfluoroalkylselenolation of alkynes. Yields shown are those of isolated products; yields determin...
Graphical Abstract
Figure 1: Selected amide bond isosteres.
Figure 2: Monofluoroalkene as an amide bond isostere.
Scheme 1: Synthesis of Cbz-Gly-ψ[(Z)-CF=CH]-Gly using a HWE olefination by Sano and co-workers.
Scheme 2: Synthesis of Phth-Gly-ψ[CF=CH]-Gly using the Julia–Kocienski olefination by Lequeux and co-workers.
Scheme 3: Synthesis of Boc-Nva-ψ[(Z)-CF=CH]-Gly by Taguchi and co-workers.
Figure 3: Mutant tripeptide containing two different peptide bond isosteres.
Scheme 4: Chromium-mediated synthesis of Boc-Ser(PMB)-ψ[(Z)-CF=CH]-Gly-OMe by Konno and co-workers.
Scheme 5: Synthesis of Cbz-Gly-ψ[(E)-CF=C]-Pro by Sano and co-workers.
Scheme 6: Synthesis of Cbz-Gly-ψ[(Z)-CF=C]-Pro by Sano and co-workers.
Scheme 7: Stereoselective synthesis of Fmoc-Gly-ψ[(Z)-CF=CH]-Phe by Pannecoucke and co-workers.
Scheme 8: Ring-closure metathesis to prepare Gly-ψ[(E)-CF=CH]-Phg by Couve-Bonnaire and co-workers.
Scheme 9: Stereoselective synthesis of Fmoc-Gly-ψ[(Z)-CF=CH]-Phe by Dory and co-workers.
Scheme 10: Diastereoselective addition of Grignard reagents to sulfinylamines derived from α-fluoroenals by Pa...
Scheme 11: NHC-mediated synthesis of monofluoroalkenes by Otaka and co-workers.
Scheme 12: Stereoselective synthesis of Boc-Tyr-ψ[(Z)-CF=CH]-Gly by Altman and co-workers.
Scheme 13: Synthesis of the tripeptide Boc-Asp(OBn)-Pro-ψ[(Z)-CF=CH)-Val-CH2OH by Miller and co-workers.
Scheme 14: Copper-catalyzed synthesis of monofluoralkenes by Taguchi and co-workers.
Scheme 15: One-pot intramolecular redox reaction to access amide-type isosteres by Otaka and co-workers.
Scheme 16: Copper-mediated reduction, transmetalation and asymmetric alkylation by Fujii and co-workers.
Scheme 17: Synthesis of (E)-monofluoroalkene-based dipeptide isostere by Fujii and co-workers.
Scheme 18: Diastereoselective synthesis of MeOCO-Val-ψ[(Z)-CF=C]-Pro isostere by Chang and co-workers.
Scheme 19: Asymmetric synthesis of Fmoc-Ala-ψ[(Z)-CF=C]-Pro by Pannecoucke and co-workers.
Scheme 20: Synthesis of Fmoc-Val-ψ[(E)-CF=C]-Pro by Pannecoucke and co-workers.
Figure 4: BMS-790052 and its fluorinated analogue.
Figure 5: Bioactivities of pentapeptide analogues based on the relative maximum agonistic activity at 10 nM o...
Figure 6: Structures and affinities of the Leu-enkephalin and its fluorinated analogue. The affinity towards ...
Figure 7: Activation of the opioid receptor DOPr by Leu-enkephaline and a fluorinated analogue.
Graphical Abstract
Scheme 1: Intramolecular site-selective iodoarylation of 1,1-difluoro-1-alkenes bearing a biaryl group.
Scheme 2: Mechanism for formation of 3a.
Figure 1: ORTEP diagram of 2a with 50% ellipsoid probability.
Scheme 3: Transformation of a CF2I group of 2a into a CHF2 group.
Scheme 4: Construction of seven-membered carbocycles via iodoarylation of 5.
Figure 2: ORTEP diagram of 6a with 50% ellipsoid probability.
Scheme 5: Selective HI elimination from 6a.
Graphical Abstract
Figure 1: (a) UV–vis absorption and (b) fluorescence spectra of 1–4 in THF.
Figure 2: Fluorescence spectra of 1 and 3 in H2O:DMSO (9:1).
Scheme 1: Use of 1 as fluorogenic probe for DPP-4 activity.
Scheme 2: Synthesis of fluorogenic probe H-Gly-Pro-1.
Figure 3: Fluorescence spectra of 1 and H-Gly-Pro-1. Measurement conditions: 1.0 × 10−5 M in H2O:DMSO (9:1), ...
Figure 4: Fluorescence intensity changes of H-Gly-Pro-1 on addition of DPP-4.
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.
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).
Graphical Abstract
Figure 1: A) Natural threonine and its trifluoromethyl analogues sawhorse projections. B) Structure of Boc-pr...
Scheme 1: Synthesis of (2S,3R)-Boc-CF3-Thr(Bzl) 9.
Scheme 2: Synthesis of (2S,3S)-Boc-CF3-Thr 14.
Scheme 3: Synthesis of pentapeptides 1a–4a and 1b–4b.
Figure 2: Probability distribution of the peptide conformations as a function of end-to-end distance (defined...
Figure 3: Probability distribution of the peptide dihedral angles ψ for the three central residues Val2 (blac...
Figure 4: Effects of compounds 1–4 on Aβ1-42 fibrillization assessed by ThT-fluorescence spectroscopy at 10:1...
Graphical Abstract
Figure 1: (a) Structures of isoleucine (1), leucine (2), and their fluorinated analogues 5,5,5-trifluoroisole...
Figure 2: Percentage of substrate remaining after incubation for 120 min (left) and 24 h (right) with α-chymo...
Figure 3: Cleavage positions observed in the digestion of library peptides with α-chymotrypsin.
Figure 4: Percentage of substrate remaining after incubation for 120 min (left) and 24 h (right) with pepsin ...
Figure 5: Cleavage positions for digestion of the different peptides with pepsin.
Figure 6: Percentage of substrate remaining after incubation for 120 min (left) and 24 h (right) with elastas...
Figure 7: Cleavage positions for digestion of the different peptides with elastase.
Figure 8: Percentage of substrate remaining after incubation for 120 min (left) and 24 h (right) with protein...
Figure 9: Cleavage positions found with proteinase K.
Figure 10: Dimension of stabilization or destabilization upon TfIle or HfLeu incorporation compared to the non...
Graphical Abstract
Scheme 1: The synthesis of anti-2,3-difluorobutan-1,4-diol (anti-5) [17].
Scheme 2: Improved epoxide opening and deoxofluorination conditions.
Scheme 3: Attempted synthesis of anti-5 via acetonide protection.
Scheme 4: Completion of the synthesis of anti-5.
Scheme 5: Synthesis of (±)-syn-5.
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.
Graphical Abstract
Figure 1: Representative examples of recent 5-HT1AR agonists [3-9].
Scheme 1: Synthesis of FEMPT (7).
Scheme 2: Radiosynthetic scheme for the microfluidic flow synthesis of [18F]fluoroethyltosylate (10) and [18F...
Figure 2: (A) Incorporation yield of [18F]fluoride versus flow rate, red line 180 °C, blue line 150 °C, moder...
Figure 3: Analysis of the final formulated product by LC–MS, using the trapping system to improve the sensiti...
Graphical Abstract
Figure 1: C–F activation of benzylic fluorides to generate benzylamine or diarylmethane products.
Figure 2: 7-[2H1]-(R)-Benzyl fluoride ((R)-1).
Scheme 1: Synthesis of enantioenriched 7-[2H1]-(R)-benzyl fluoride ((R)-1) from benzaldehyde (2).
Figure 3: Partial 2H{1H} NMR (107.5 MHz) with PBLG in CHCl3 (13% w/w). (A) racemic sample of 6 (from Table 1, entry ...
Scheme 2: Synthesis of enantioenriched (S)-diarylmethane 10 from diaryl ketone 11 and confirmation of configu...
Figure 4: Possible reactive intermediates for C–F activation of benzyl fluoride 1 with strong hydrogen bond d...
Graphical Abstract
Figure 1: Typical examples of previously reported negative-type liquid crystals containing a CF2CF2-carbocycl...
Scheme 1: Improved short-step synthetic protocol for multicyclic mesogens 1 and 2.
Scheme 2: Short-step approach to CF2CF2-containing carbocycles.
Figure 2: (a) Expected products of over-reaction in the Grignard reaction of dimethyl tetrafluorosuccinate (7...
Scheme 3: Mechanism for the reaction of γ-keto ester 6 with vinyl Grignard reagents.
Scheme 4: First multigram-scale preparation of CF2CF2-containing multicyclic mesogens.
Scheme 5: Stereochemical assignment of the ring-closing metathesis products.
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...
Graphical Abstract
Scheme 1: Phthalide and fluorinated phthalides (1).
Scheme 2: Plausible reaction mechanism for the formation of phthalide 1a.
Scheme 3: Synthesis of fluorinated phthalides 1.
Scheme 4: Asymmetric synthesis of 1a using a chiral auxiliary.
Scheme 5: Catalytic asymmetric synthesis of 1a.
Graphical Abstract
Scheme 1: Silicon-mediated Mukaiyama-type aldol reaction of octyl 2-(pentafluoro-λ6-sulfanyl)acetate (1) with ...
Figure 1: Newman projections of the syn- and the anti-diastereomeric aldol addition products.
Scheme 2: Mechanism of the formation of aldol addition products.
Scheme 3: Formation of (E)-configured aldol condensation products.
Scheme 4: Anticipated mechanism of formation of aldol condensation products.
Scheme 5: Synthesis of SF5-substituted acetmorpholide 8.
Scheme 6: Intermediate formation of the (Z)-ketene aminal from morpholide 8 with TMSOTf/ Et3N and subsequent ...
Graphical Abstract
Figure 1: Acid strength (pKa) of various organic acids in acetonitrile or water (nr = not reported) [12-14].
Figure 2: Examples of functional molecules containing an N-triflylbenzamide.
Scheme 1: Synthesis of the strongly acidic benzamide derivatives.
Scheme 2: SNAr reactions of fluoro-substituted benzamide derivatives.
Scheme 3: Cross-coupling reactions of N-triflylbenzoic acid derivatives.
Scheme 4: Hydrolysis rates of the 4-bromobenzoic acid derivatives.
Figure 3: Content (percent) of super acids (0.5 mg/mL) over time (hours) in H3PO4/H2O/MeOH 17:3:20 at 50 °C.
Graphical Abstract
Scheme 1: Synthesis of chiral α-fluoroalkylated tertiary alcohols.
Scheme 2: Scope of fluoroalkylated pyruvates. Yields were determined by 19F NMR analysis using benzotrifluori...
Scheme 3: Catalytic asymmetric methylation of the simple perfluoroalkylated ketone 3a. Yields were determined...