Search for "C–F bond" in Full Text gives 59 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2025, 21, 146–154, doi:10.3762/bjoc.21.8
Graphical Abstract
Scheme 1: C–F bond activation through β-fluorine elimination via metalacyclopropanes.
Scheme 2: Synthesis of 2-arylbenzofurans 3 via the coupling of 1 with 2. Isolated yields are given. aNi(cod)2...
Scheme 3: Synthesis of 2-phenylbenzothiophene (5).
Scheme 4: Orthogonal approach to 2,5-diarylbenzofuran 3fa.
Scheme 5: Possible mechanisms.
Scheme 6: Formation of nickelacyclopropane Eb in a stoichiometric reaction.
Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270
Graphical Abstract
Figure 1: Fluorotriphenylene derivatives and their nonfluorinated homologs obtained by SNFAr from 2,2'-dilith...
Scheme 1: Synthesis, yields, and nomenclature of 1,2,4-trifluoro-6,7,10,11-tetraalkoxy-3-(perfluorophenyl)tri...
Figure 2: Single crystal structure of 1,2,4-trifluoro-3-(perfluorophenyl)triphenylene (F) viewed along the ma...
Figure 3: POM textures, observed between crossed polarizers of Janus and dimer, F6, F12, G66, and G48, respec...
Figure 4: Comparative bar graph summarizing the thermal behavior of Fn, BTP6, and PHn derivatives (2nd heatin...
Figure 5: Representative S/WAXS patterns of Fn and Gnm compounds.
Figure 6: Absorption (a) and emission (b) spectra of F6 and G66, measured in different solvents at a concentr...
Figure 7: DFT calculated frontier molecular orbitals and optimized molecular structures for F1 and G11.
Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258
Graphical Abstract
Figure 1: Example bioactive compounds containing cyclic scaffolds potentially accessible by HVI chemistry.
Figure 2: A general mechanism for HVI-mediated endo- or exo-halocyclisation.
Scheme 1: Metal-free synthesis of β-fluorinated piperidines 6. Ts = tosyl.
Scheme 2: Intramolecular aminofluorination of unactivated alkenes with a palladium catalyst.
Scheme 3: Aminofluorination of alkenes in the synthesis of enantiomerically pure β-fluorinated piperidines. P...
Scheme 4: Synthesis of β-fluorinated piperidines.
Scheme 5: Intramolecular fluoroaminations of unsaturated amines published by Li.
Scheme 6: Intramolecular aminofluorination of unsaturated amines using 1-fluoro-3,3-dimethylbenziodoxole (12)...
Scheme 7: 3-fluoropyrrolidine synthesis. aDiastereomeric ratio (cis/trans) determined by 19F NMR analysis.
Scheme 8: Kitamura’s synthesis of 3-fluoropyrrolidines. Values in parentheses represent the cis:trans ratio.
Scheme 9: Jacobsen’s enantio- and diastereoselective protocol for the synthesis of syn-β-fluoroaziridines 15.
Scheme 10: Different HVI reagents lead to different diastereoselectivity in aminofluorination competing with c...
Scheme 11: Fluorocyclisation of unsaturated alcohols and carboxylic acids to make tetrahydrofurans, fluorometh...
Scheme 12: Oxyfluorination of unsaturated alcohols.
Scheme 13: Synthesis and mechanism of fluoro-benzoxazepines.
Scheme 14: Intramolecular fluorocyclisation of unsaturated carboxylic acids. Yield of isolated product within ...
Scheme 15: Synthesis of fluorinated tetrahydrofurans and butyrolactone.
Scheme 16: Synthesis of fluorinated oxazolines 32. aReaction time increased to 40 hours. Yields refer to isola...
Scheme 17: Electrochemical synthesis of fluorinated oxazolines.
Scheme 18: Electrochemical synthesis of chromanes.
Scheme 19: Synthesis of fluorinated oxazepanes.
Scheme 20: Enantioselective oxy-fluorination with a chiral aryliodide catayst.
Scheme 21: Catalytic synthesis of 5‑fluoro-2-aryloxazolines using BF3·Et2O as a source of fluoride and an acti...
Scheme 22: Intramolecular carbofluorination of alkenes.
Scheme 23: Intramolecular chlorocyclisation of unsaturated amines.
Scheme 24: Synthesis of chlorinated cyclic guanidines 44.
Scheme 25: Synthesis of chlorinated pyrido[2,3-b]indoles 46.
Scheme 26: Chlorolactonization and chloroetherification reactions.
Scheme 27: Proposed mechanism for the synthesis of chloromethyl oxazolines 49.
Scheme 28: Oxychlorination to form oxazine and oxazoline heterocycles promoted by BCl3.
Scheme 29: Aminobromocyclisation of homoallylic sulfonamides 53. The cis:trans ratios based on the 1H NMR of t...
Scheme 30: Synthesis of cyclic imines 45.
Scheme 31: Synthesis of brominated pyrrolo[2,3-b]indoles 59.
Scheme 32: Bromoamidation of alkenes.
Scheme 33: Synthesis of brominated cyclic guanidines 61 and 61’.
Scheme 34: Intramolecular bromocyclisation of N-oxyureas.
Scheme 35: The formation of 3-bromoindoles.
Scheme 36: Bromolactonisation of unsaturated acids 68.
Scheme 37: Synthesis of 5-bromomethyl-2-oxazolines.
Scheme 38: Synthesis of brominated chiral morpholines.
Scheme 39: Bromoenolcyclisation of unsaturated dicarbonyl groups.
Scheme 40: Brominated oxazines and oxazolines with BBr3.
Scheme 41: Synthesis of 5-bromomethtyl-2-phenylthiazoline.
Scheme 42: Intramolecular iodoamination of unsaturated amines.
Scheme 43: Formation of 3-iodoindoles.
Scheme 44: Iodoetherification of 2,2-diphenyl-4-penten-1-carboxylic acid (47’) and 2,2-diphenyl-4-penten-1-ol (...
Scheme 45: Synthesis of 5-iodomethyl-2-oxazolines.
Scheme 46: Synthesis of chiral iodinated morpholines. aFrom the ʟ-form of the amino acid starting material. Th...
Scheme 47: Iodoenolcyclisation of unsaturated dicarbonyl compounds 74.
Scheme 48: Synthesis of 5-iodomethtyl-2-phenylthiazoline (87).
Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214
Graphical Abstract
Figure 1: Classification of LSF reactions in this review.
Scheme 1: C(sp2)–H trifluoromethylation of heteroarenes.
Scheme 2: C(sp2)–H and C(sp3)–H alkylation of complex molecules.
Scheme 3: Electrochemical oxidation-induced intermolecular aromatic C–H sulfonamidation.
Scheme 4: Bioconjugation of tyrosine with (a) phenothiazine and (b) urazole derivatives.
Scheme 5: Electrochemical iodoamination of indoles using unactivated amines.
Scheme 6: Allylic C(sp3)–H aminations with sulfonamides.
Scheme 7: Electrochemical benzylic oxidation of C–H bonds.
Scheme 8: Site-selective electrooxidation of methylarenes to aromatic acetals.
Scheme 9: Electrochemical activation of C–H by electron-deficient W2C nanocrystals.
Scheme 10: α-Acyloxy sulfide preparation via C–H/OH cross-dehydrogenative coupling.
Scheme 11: Aromatic C–H-bond thiolation.
Scheme 12: C(sp2)–H functionalization for the installation of sulfonamide groups.
Scheme 13: Preparation of (hetero)aryl chlorides and vinyl chloride with 1,2-dichloroethane. aCu(OAc)2 (0.05 e...
Scheme 14: Electrochemical dual-oxidation enables access to α-chlorosulfoxides.
Scheme 15: Regio- and chemoselective formyloxylation–bromination/chlorination/trifluoromethylation of alkenes.
Scheme 16: Aziridine formation by coupling amines and alkenes.
Scheme 17: Formation of iminosulfide ethers via difunctionalization of an isocyanide.
Scheme 18: Synthesis of 1,3-difunctionalized molecules via C–C-bond cleavage of arylcyclopropane.
Scheme 19: Electrooxidative amino- and oxyselenation of alkenes. VBImBr = 1-butyl-3-vinylimidazolium bromide.
Scheme 20: Electrooxidative dehydrogenative [4 + 2] annulation of indole derivatives.
Scheme 21: Electrochemical cyclization combined with alkoxylation of triticonazole.
Scheme 22: Electrochemically tuned oxidative [4 + 2] annulation of olefins with hydroxamic acids.
Scheme 23: Electrosynthesis of indole derivatives via cyclization of 2-ethynylanilines.
Scheme 24: Allylic C–H oxidation of mono-, di-, and sesquiterpenes.
Scheme 25: Oxidation of unactivated C–H bonds.
Scheme 26: Fluorination of C(sp3)–H bonds. rAP = rapid alternating polarity.
Scheme 27: C(sp3)–H α-cyanation of secondary piperidines.
Scheme 28: Selective electrochemical hydrolysis of hydrosilanes to silanols.
Scheme 29: Organocatalytic electrochemical amination of benzylic C–H bonds.
Scheme 30: Iodide ion-initiated anodic oxidation reactions.
Scheme 31: Mn(III/IV) electro-catalyzed C(sp3)–H azidation.
Scheme 32: Tailored cobalt–salen complexes enable electrocatalytic intramolecular allylic C–H functionalizatio...
Scheme 33: Cobalt–salen complexes-induced electrochemical (cyclo)additions.
Scheme 34: Electrochemical 1,2-diarylation of alkenes enabled by direct dual C–H functionalization of electron...
Scheme 35: Cobalt-electrocatalyzed atroposelective C–H annulation.
Scheme 36: Nickel-electrocatalyzed C(sp2)–H alkoxylation with secondary alcohols.
Scheme 37: Nickel-catalyzed electrochemical enantioselective amination.
Scheme 38: Ruthenium-electrocatalyzed C(sp2)–H mono- and diacetoxylation.
Scheme 39: Rhodium(III)-catalyzed aryl-C–H phosphorylation enabled by anodic oxidation-induced reductive elimi...
Scheme 40: Asymmetric Lewis-acid catalysis for the synthesis of non-racemic 1,4-dicarbonyl compounds.
Scheme 41: Electrochemical enantioselective C(sp3)–H alkenylation.
Scheme 42: Palladium-catalyzed electrochemical dehydrogenative cross-coupling.
Scheme 43: Ir-electrocatalyzed vinylic C(sp2)–H activation for the annulation between acrylic acids and alkyne...
Scheme 44: Electrochemical gold-catalyzed C(sp3)–C(sp) coupling of alkynes and arylhydrazines.
Scheme 45: Photoelectrochemical alkylation of C–H heteroarenes using organotrifluoroborates.
Scheme 46: Mn-catalyzed photoelectro C(sp3)–H azidation.
Scheme 47: Photoelectrochemical undirected C–H trifluoromethylations of (Het)arenes.
Scheme 48: Photoelectrochemical dehydrogenative cross-coupling of heteroarenes with aliphatic C–H bonds.
Scheme 49: C–H amination via photoelectrochemical Ritter-type reaction.
Scheme 50: Photoelectrochemical multiple oxygenation of C–H bonds.
Scheme 51: Accelerated C(sp3)–H heteroarylations by the f-EPC system.
Scheme 52: Photoelectrochemical cross-coupling of amines.
Scheme 53: Birch electroreduction of arenes. GSW = galvanized steel wire.
Scheme 54: Electroreductive deuterations.
Scheme 55: Chemoselective electrosynthesis using rapid alternating polarity.
Scheme 56: Electroreductive olefin–ketone coupling.
Scheme 57: Electroreductive approach to radical silylation.
Scheme 58: Electrochemical borylation of alkyl halides. CC = carbon close.
Scheme 59: Radical fluoroalkylation of alkenes.
Scheme 60: Electrochemical defluorinative hydrogenation/carboxylation.
Scheme 61: Electrochemical decarboxylative olefination.
Scheme 62: Electrochemical decarboxylative Nozaki–Hiyama–Kishi coupling.
Scheme 63: Nickel-catalyzed electrochemical reductive relay cross-coupling.
Scheme 64: Electrochemical chemo- and regioselective difunctionalization of 1,3-enynes.
Scheme 65: Electrocatalytic doubly decarboxylative crosscoupling.
Scheme 66: Electrocatalytic decarboxylative crosscoupling with aryl halides.
Scheme 67: Nickel-catalyzed electrochemical reductive coupling of halides.
Scheme 68: Nickel-electrocatalyzed enantioselective carboxylation with CO2.
Scheme 69: Reductive electrophotocatalysis for borylation.
Scheme 70: Electromediated photoredox catalysis for selective C(sp3)–O cleavages of phosphinated alcohols to c...
Scheme 71: Stereoselective electro-2-deoxyglycosylation from glycals. MFE = methyl nonafluorobutyl ether.
Scheme 72: Electrochemical peptide modifications.
Scheme 73: Electrochemical α-deuteration of amides.
Scheme 74: Electrochemical synthesis of gem-diselenides.
Scheme 75: Site-selective electrochemical aromatic C–H amination.
Scheme 76: Electrochemical coupling of heteroarenes with heteroaryl phosphonium salts.
Scheme 77: Redox-neutral strategy for the dehydroxyarylation reaction.
Scheme 78: Nickel-catalyzed electrochemical C(sp3)–C(sp2) cross-coupling of benzyl trifluoroborate and halides....
Scheme 79: Paired electrocatalysis for C(sp3)–C(sp2) coupling.
Scheme 80: Redox-neutral strategy for amination of aryl bromides.
Scheme 81: Redox-neutral cross-coupling of aryl halides with weak N-nucleophiles. aProtocol with (+) RVC | RVC...
Scheme 82: Nickel-catalyzed N-arylation of NH-sulfoximines with aryl halides.
Scheme 83: Esterification of carboxylic acids with aryl halides.
Scheme 84: Electrochemically promoted nickel-catalyzed carbon–sulfur-bond formation. GFE = graphite felt elect...
Scheme 85: Electrochemical deoxygenative thiolation by Ni-catalysis. GFE = graphite felt electrode; NFE = nick...
Scheme 86: Electrochemical coupling of peptides with aryl halides.
Scheme 87: Paired electrolysis for the phosphorylation of aryl halides. GFE = graphite felt electrode, FNE = f...
Scheme 88: Redox-neutral alkoxyhalogenation of alkenes.
Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208
Graphical Abstract
Figure 1: Synthesis of trihalogenated pyrans: a) Chiron approach to multivicinal inter-halide derived from al...
Scheme 1: Synthesis of halogenated talopyranose analogues 13–15, and 17 that include a 2,3-cis, 3,4-cis relat...
Figure 2: Direct comparison of 19F resonances of halogenated talose analogues 12–15 (19F NMR; 470 MHz, CDCl3)....
Figure 3: X-ray analysis of compound 13–15, 17, and α-ᴅ-talose 18. ORTEP diagram showing 50% thermal ellipsoi...
Figure 4: Packing arrangement of compound compound 15; a) View down the b axis; b) proposed intermolecular in...
Beilstein J. Org. Chem. 2024, 20, 1955–1966, doi:10.3762/bjoc.20.171
Graphical Abstract
Scheme 1: 1,2-Difluoroethylene synthesis from HFO-1123.
Scheme 2: 1,2-Difluoroethylene synthesis from CFC-112 and HCFC-132.
Scheme 3: 1,2-Difluoroethylene synthesis from HFC-143.
Scheme 4: 1,2-Difluoroethylene synthesis from HCFC-142 via HCFC-142a.
Scheme 5: 1,2-Difluoroethylene synthesis from CFO-1112.
Scheme 6: 1,2-Difluoroethylene synthesis from 1,2-dichloroethylene.
Scheme 7: 1,2-Difluoroethylene synthesis from perfluoropropyl vinyl ether.
Scheme 8: Deuteration reaction of 1,2-difluoroethylene.
Scheme 9: Halogen addition to 1,2-difluoroethylene.
Scheme 10: Hypohalite addition to 1,2-difluoroethylene.
Scheme 11: N-Bromobis(trifluoromethyl)amine addition to 1,2-difluoroethylene.
Scheme 12: N-Chloroimidobis(sulfonyl fluoride) addition to 1,2-difluoroethylene.
Scheme 13: Trichlorosilane addition to 1,2-difluoroethylene.
Scheme 14: SF5Br addition to 1,2-difluoroethylene.
Scheme 15: PCl3/O2 addition to 1,2-difluoroethylene.
Scheme 16: Reaction of tetramethyldiarsine with 1,2-difluoroethylene.
Scheme 17: Reaction of trichlorofluoromethane with 1,2-difluoroethylene.
Scheme 18: Addition of perfluoroalkyl iodides to 1,2-difluoroethylene.
Scheme 19: Cyclopropanation of 1,2-difluoroethylene.
Scheme 20: Diels–Alder reaction of 1,2-difluoroethylene and hexachlorocyclopentadiene.
Scheme 21: Cycloaddition reaction of 1,2-difluoroethylene and fluorinated ketones.
Scheme 22: Cycloaddition reaction of 1,2-difluoroethylene and perfluorinated aldehydes.
Scheme 23: Photochemical cycloaddition of 1,2-difluoroethylene and hexafluorodiacetyl.
Scheme 24: Reaction of 1,2-difluoroethylene with difluorosilylene.
Scheme 25: Reaction of 1,2-difluoroethylene with aryl iodides.
Beilstein J. Org. Chem. 2024, 20, 1785–1793, doi:10.3762/bjoc.20.157
Graphical Abstract
Scheme 1: Examples of fluorination using hypervalent iodine(III) reagents 1 and 2.
Scheme 2: Preparations and reactions of hypervalent iodine(V) fluorides.
Figure 1: Bicyclic difluoro(aryl)-λ5-iodanes.
Scheme 3: Attempted oxidative fluorination of hypervalent iodine(III) amides.
Scheme 4: Synthesis of methyl(trifluoromethyl)fluoroiodane 15.
Scheme 5: Synthesis of bis(trifluoromethyl)fluoroiodane 19.
Scheme 6: Reaction of phenylmagnesium bromide with bis(trifluoromethyl)trifluoroiodane 22.
Figure 2: Molecular structure of difluoroiodane 6 showing 50% displacement ellipsoids.
Figure 3: Stability of difluoroiodane 6 in air in dry CD3CN (blue line), dry CDCl3 with 2.4 equivalents of dr...
Figure 4: Order of hydrolytic stability for the four hypervalent iodine(V) fluorides.
Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140
Graphical Abstract
Figure 1: a) Pseudoequatorial and pseudoaxial conformations of pyrrolidine. b) Cis- and trans-isomers of 3-fl...
Figure 2: Flat representations of 2,3-, 3,4-, and 2,4-difluoropyrrolidines. The potential effects resulting f...
Figure 3: MAE comparing the geometry parameters (bond length, bond angle, and dihedral angle) obtained from D...
Figure 4: Exhaustive illustration of all conformational, configurational, and constitutional isomers of diflu...
Figure 5: Stable difluorinated pyrrolidines derived from gas-phase calculations performed at the B3LYP-D3BJ/6...
Figure 6: σCH→σ*CF fluorine gauche interaction, which also occurred in 19, and anomeric interaction in isomer ...
Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137
Graphical Abstract
Figure 1: A) Benzylic fluorides in bioactive compounds, with B) the relative BDEs of different benzylic C–H b...
Figure 2: Base-mediated benzylic fluorination with Selectfluor.
Figure 3: Sonochemical base-mediated benzylic fluorination with Selectfluor.
Figure 4: Mono- and difluorination of nitrogen-containing heteroaromatic benzylic substrates.
Figure 5: Palladium-catalysed benzylic C–H fluorination with N-fluoro-2,4,6-trimethylpyridinium tetrafluorobo...
Figure 6: Palladium-catalysed, PIP-directed benzylic C(sp3)–H fluorination of α-amino acids and proposed mech...
Figure 7: Palladium-catalysed monodentate-directed benzylic C(sp3)–H fluorination of α-amino acids.
Figure 8: Palladium-catalysed bidentate-directed benzylic C(sp3)–H fluorination.
Figure 9: Palladium-catalysed benzylic fluorination using a transient directing group approach. Ratio refers ...
Figure 10: Outline for benzylic C(sp3)–H fluorination via radical intermediates.
Figure 11: Iron(II)-catalysed radical benzylic C(sp3)–H fluorination using Selectfluor.
Figure 12: Silver and amino acid-mediated benzylic fluorination.
Figure 13: Copper-catalysed radical benzylic C(sp3)–H fluorination using NFSI.
Figure 14: Copper-catalysed C(sp3)–H fluorination of benzylic substrates with electrochemical catalyst regener...
Figure 15: Iron-catalysed intramolecular fluorine-atom-transfer from N–F amides.
Figure 16: Vanadium-catalysed benzylic fluorination with Selectfluor.
Figure 17: NDHPI-catalysed radical benzylic C(sp3)–H fluorination with Selectfluor.
Figure 18: Potassium persulfate-mediated radical benzylic C(sp3)–H fluorination with Selectfluor.
Figure 19: Benzylic fluorination using triethylborane as a radical chain initiator.
Figure 20: Heterobenzylic C(sp3)–H radical fluorination with Selectfluor.
Figure 21: Benzylic fluorination of phenylacetic acids via a charge-transfer complex. NMR yields in parenthese...
Figure 22: Oxidative radical photochemical benzylic C(sp3)–H strategies.
Figure 23: 9-Fluorenone-catalysed photochemical radical benzylic fluorination with Selectfluor.
Figure 24: Xanthone-photocatalysed radical benzylic fluorination with Selectfluor II.
Figure 25: 1,2,4,5-Tetracyanobenzene-photocatalysed radical benzylic fluorination with Selectfluor.
Figure 26: Xanthone-catalysed benzylic fluorination in continuous flow.
Figure 27: Photochemical phenylalanine fluorination in peptides.
Figure 28: Decatungstate-photocatalyzed versus AIBN-initiated selective benzylic fluorination.
Figure 29: Benzylic fluorination using organic dye Acr+-Mes and Selectfluor.
Figure 30: Palladium-catalysed benzylic C(sp3)–H fluorination with nucleophilic fluoride.
Figure 31: Manganese-catalysed benzylic C(sp3)–H fluorination with AgF and Et3N·3HF and proposed mechanism. 19...
Figure 32: Iridium-catalysed photocatalytic benzylic C(sp3)–H fluorination with nucleophilic fluoride and N-ac...
Figure 33: Iridium-catalysed photocatalytic benzylic C(sp3)–H fluorination with TBPB HAT reagent.
Figure 34: Silver-catalysed, amide-promoted benzylic fluorination via a radical-polar crossover pathway.
Figure 35: General mechanism for oxidative electrochemical benzylic C(sp3)–H fluorination.
Figure 36: Electrochemical benzylic C(sp3)–H fluorination with HF·amine reagents.
Figure 37: Electrochemical benzylic C(sp3)–H fluorination with 1-ethyl-3-methylimidazolium trifluoromethanesul...
Figure 38: Electrochemical benzylic C(sp3)–H fluorination of phenylacetic acid esters with HF·amine reagents.
Figure 39: Electrochemical benzylic C(sp3)–H fluorination of triphenylmethane with PEG and CsF.
Figure 40: Electrochemical benzylic C(sp3)–H fluorination with caesium fluoride and fluorinated alcohol HFIP.
Figure 41: Electrochemical secondary and tertiary benzylic C(sp3)–H fluorination. GF = graphite felt. DCE = 1,...
Figure 42: Electrochemical primary benzylic C(sp3)–H fluorination of electron-poor toluene derivatives. Ring f...
Figure 43: Electrochemical primary benzylic C(sp3)–H fluorination utilizing pulsed current electrolysis.
Beilstein J. Org. Chem. 2024, 20, 921–930, doi:10.3762/bjoc.20.82
Graphical Abstract
Figure 1: Advantages of acyl fluorides compared to acyl chlorides, previous work on BT-SRF reagents [29-33] and a su...
Scheme 1: Scope of the BT-SCF3-mediated deoxygenative fluorination of carboxylic acids 1. Reactions were perf...
Scheme 2: Scope of the one-pot BT-SCF3-mediated deoxygenative coupling of carboxylic acids and amines via acy...
Scheme 3: One-pot BT-SCF3-mediated deoxygenative coupling of amino acids. Isolated yields after column chroma...
Scheme 4: Plausible mechanism for the deoxyfluorination of carboxylic acids with BT-SCF3.
Scheme 5: Mechanistic experiments. (a) Conversion of thioester 3a into acyl fluoride 2a in the presence of DI...
Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40
Graphical Abstract
Scheme 1: Synthesis of 2,3-dibromo-1,1,1,4,4,4-hexafluorobutane (2).
Scheme 2: Synthesis of (E)-butene 3a.
Scheme 3: Isomerization reaction of (E)-butene 3a to (Z)-butene 3b.
Scheme 4: Synthesis of 2-chloro-3-iodo-1,1,1,4,4,4-hexafluorobutane (5).
Scheme 5: Dehydrohalogenation reaction of 2-chloro-3-iodo-1,1,1,4,4,4-hexafluorobutane (5).
Scheme 6: The reaction of silane 8 with I2/KF.
Scheme 7: The reaction of 3a with iPrMgCl and 4-fluorobenzaldehyde (9).
Scheme 8: The reaction of olefin 3a with iPrMgCl.
Scheme 9: The reaction of (E)-butene 3a with BuLi.
Scheme 10: The reaction of allene 11 with bromine.
Scheme 11: The reaction of allene 11 with ICl.
Scheme 12: Synthesis of 2,3-dibromo-2-chloro-1,1,1,4,4,4-hexafluorobutane (16).
Scheme 13: Synthesis of (Z, E)-2-bromo-3-chloro-1,1,1,4,4,4-hexafluorobut-2-enes (17a,b).
Scheme 14: The reaction of olefins 17a,b with BuLi.
Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35
Graphical Abstract
Scheme 1: Transition-metal-catalyzed C–XRF bond formation by C–H bond activation: an overview.
Scheme 2: Cu(OAc)2-promoted mono- and ditrifluoromethylthiolation of benzamide derivatives derived from 8-ami...
Scheme 3: Trifluoromethylthiolation of azacalix[1]arene[3]pyridines using copper salts and a nucleophilic SCF3...
Scheme 4: Working hypothesis for the palladium-catalyzed C–H trifluoromethylthiolation reaction.
Scheme 5: Trifluoromethylthiolation of 2-arylpyridine derivatives and analogs by means of palladium-catalyzed...
Scheme 6: C(sp2)–SCF3 bond formation by Pd-catalyzed C–H bond activation using AgSCF3 and Selectfluor® as rep...
Scheme 7: Palladium-catalyzed ortho-trifluoromethylthiolation of 2-arylpyridine derivatives reported by the g...
Scheme 8: Palladium-catalyzed ortho-trifluoromethylthiolation of 2-arylpyridine and analogs reported by Anbar...
Scheme 9: Mono- and ditrifluoromethylthiolation of benzamide derivatives derived from 8-aminoquinoline using ...
Scheme 10: Regioselective Cp*Rh(III)-catalyzed directed trifluoromethylthiolation reported by the group of Li [123]...
Scheme 11: Cp*Co(III)-catalyzed ortho-trifluoromethylthiolation of 2-phenylpyridine and 2-phenylpyrimidine der...
Scheme 12: Cp*Co(III)-catalyzed ortho-trifluoromethylthiolation of 2-phenylpyridine and 6-phenylpurine derivat...
Scheme 13: Diastereoselective trifluoromethylthiolation of acrylamide derivatives derived from 8-aminoquinolin...
Scheme 14: C(sp3)–SCF3 bond formation on aliphatic amide derivatives derived from 8-aminoquinoline by palladiu...
Scheme 15: Regio- and diastereoselective difluoromethylthiolation of acrylamides under palladium catalysis rep...
Scheme 16: Palladium-catalyzed (ethoxycarbonyl)difluoromethylthiolation reaction of 2-(hetero)aryl and 2-(α-ar...
Scheme 17: Pd(II)-catalyzed trifluoromethylselenolation of benzamides derived from 5-methoxy-8-aminoquinoline ...
Scheme 18: Pd(II)-catalyzed trifluoromethylselenolation of acrylamide derivatives derived from 5-methoxy-8-ami...
Scheme 19: Transition-metal-catalyzed dehydrogenative 2,2,2-trifluoroethoxylation of (hetero)aromatic derivati...
Scheme 20: Pd(II)-catalyzed ortho-2,2,2-trifluoroethoxylation of N-sulfonylbenzamides reported by the group of...
Scheme 21: Pd(II)-catalyzed selective 2,2,2-trifluoroethoxylation and other fluoroalkoxylations of naphthalene...
Scheme 22: Pd(II)-catalyzed selective ortho-2,2,2-trifluoroethoxylation of benzaldehyde derivatives by means o...
Scheme 23: Pd(II)-catalyzed selective ortho-2,2,2-trifluoroethoxylation (and other fluoroalkoxylations) of ben...
Scheme 24: Pd(II)-catalyzed selective 2,2,2-trifluoroethoxylation of aliphatic amides using a bidentate direct...
Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126
Graphical Abstract
Scheme 1: Schematic overview of transition metals studied in C–H activation processes.
Scheme 2: (A) Known biological activities related to benzimidazole-based compounds; (B and C) an example of a...
Scheme 3: (A) Known biological activities related to quinoline-based compounds; (B and C) an example of a sca...
Scheme 4: (A) Known biological activities related to sulfur-containing compounds; (B and C) an example of a s...
Scheme 5: (A) Known biological activities related to aminoindane derivatives; (B and C) an example of a scand...
Scheme 6: (A) Known biological activities related to norbornane derivatives; (B and C) an example of a scandi...
Scheme 7: (A) Known biological activities related to aniline derivatives; (B and C) an example of a titanium-...
Scheme 8: (A) Known biological activities related to cyclohexylamine derivatives; (B) an example of an intram...
Scheme 9: (A) Known biologically active benzophenone derivatives; (B and C) photocatalytic oxidation of benzy...
Scheme 10: (A) Known bioactive fluorine-containing compounds; (B and C) vanadium-mediated C(sp3)–H fluorinatio...
Scheme 11: (A) Known biologically active Lythraceae alkaloids; (B) synthesis of (±)-decinine (30).
Scheme 12: (A) Synthesis of (R)- and (S)-boehmeriasin (31); (B) synthesis of phenanthroindolizidines by vanadi...
Scheme 13: (A) Known bioactive BINOL derivatives; (B and C) vanadium-mediated oxidative coupling of 2-naphthol...
Scheme 14: (A) Known antiplasmodial imidazopyridazines; (B) practical synthesis of 41.
Scheme 15: (A) Gold-catalyzed drug-release mechanism using 2-alkynylbenzamides; (B and C) chromium-mediated al...
Scheme 16: (A) Examples of anti-inflammatory benzaldehyde derivatives; (B and C) chromium-mediated difunctiona...
Scheme 17: (A and B) Manganese-catalyzed chemoselective intramolecular C(sp3)–H amination; (C) late-stage modi...
Scheme 18: (A and B) Manganese-catalyzed C(sp3)–H amination; (C) late-stage modification of a leelamine deriva...
Scheme 19: (A) Known bioactive compounds containing substituted N-heterocycles; (B and C) manganese-catalyzed ...
Scheme 20: (A) Known indoles that present GPR40 full agonist activity; (B and C) manganese-catalyzed C–H alkyl...
Scheme 21: (A) Examples of known biaryl-containing drugs; (B and C) manganese-catalyzed C–H arylation through ...
Scheme 22: (A) Known zidovudine derivatives with potent anti-HIV properties; (B and C) manganese-catalyzed C–H...
Scheme 23: (A and B) Manganese-catalyzed C–H organic photo-electrosynthesis; (C) late-stage modification.
Scheme 24: (A) Example of a known antibacterial silylated dendrimer; (B and C) manganese-catalyzed C–H silylat...
Scheme 25: (A and B) Fe-based small molecule catalyst applied for selective aliphatic C–H oxidations; (C) late...
Scheme 26: (A) Examples of naturally occurring gracilioethers; (B) the first total synthesis of gracilioether ...
Scheme 27: (A and B) Selective aliphatic C–H oxidation of amino acids; (C) late-stage modification of proline-...
Scheme 28: (A) Examples of Illicium sesquiterpenes; (B) first chemical synthesis of (+)-pseudoanisatin (80) in...
Scheme 29: (A and B) Fe-catalyzed deuteration; (C) late-stage modification of pharmaceuticals.
Scheme 30: (A and B) Biomimetic Fe-catalyzed aerobic oxidation of methylarenes to benzaldehydes (PMHS, polymet...
Scheme 31: (A) Known tetrahydroquinolines with potential biological activities; (B and C) redox-selective Fe c...
Scheme 32: (A) Known drugs containing a benzofuran unit; (B and C) Fe/Cu-catalyzed tandem O-arylation to acces...
Scheme 33: (A) Known azaindolines that act as M4 muscarinic acetylcholine receptor agonists; (B and C) intramo...
Scheme 34: (A) Known indolinones with anticholinesterase activity; (B and C) oxidative C(sp3)–H cross coupling...
Scheme 35: (A and B) Cobalt-catalyzed C–H alkenylation of C-3-peptide-containing indoles; (C) derivatization b...
Scheme 36: (A) Cobalt-Cp*-catalyzed C–H methylation of known drugs; (B and C) scope of the o-methylated deriva...
Scheme 37: (A) Known lasalocid A analogues; (B and C) three-component cobalt-catalyzed C–H bond addition; (D) ...
Scheme 38: (A and B) Cobalt-catalyzed C(sp2)–H amidation of thiostrepton.
Scheme 39: (A) Known 4H-benzo[d][1,3]oxazin-4-one derivatives with hypolipidemic activity; (B and C) cobalt-ca...
Scheme 40: (A and B) Cobalt-catalyzed C–H arylation of pyrrole derivatives; (C) application for the synthesis ...
Scheme 41: (A) Known 2-phenoxypyridine derivatives with potent herbicidal activity; (B and C) cobalt-catalyzed...
Scheme 42: (A) Natural cinnamic acid derivatives; (B and C) cobalt-catalyzed C–H carboxylation of terminal alk...
Scheme 43: (A and B) Cobalt-catalyzed C–H borylation; (C) application to the synthesis of flurbiprofen.
Scheme 44: (A) Benzothiazoles known to present anticonvulsant activities; (B and C) cobalt/ruthenium-catalyzed...
Scheme 45: (A and B) Cobalt-catalyzed oxygenation of methylene groups towards ketone synthesis; (C) synthesis ...
Scheme 46: (A) Known anticancer tetralone derivatives; (B and C) cobalt-catalyzed C–H difluoroalkylation of ar...
Scheme 47: (A and B) Cobalt-catalyzed C–H thiolation; (C) application in the synthesis of quetiapine (153).
Scheme 48: (A) Known benzoxazole derivatives with anticancer, antifungal, and antibacterial activities; (B and...
Scheme 49: (A and B) Cobalt-catalyzed C–H carbonylation of naphthylamides; (C) BET inhibitors 158 and 159 tota...
Scheme 50: (A) Known bioactive pyrrolo[1,2-a]quinoxalin-4(5H)-one derivatives; (B and C) cobalt-catalyzed C–H ...
Scheme 51: (A) Known antibacterial cyclic sulfonamides; (B and C) cobalt-catalyzed C–H amination of propargyli...
Scheme 52: (A and B) Cobalt-catalyzed intramolecular 1,5-C(sp3)–H amination; (C) late-stage functionalization ...
Scheme 53: (A and B) Cobalt-catalyzed C–H/C–H cross-coupling between benzamides and oximes; (C) late-state syn...
Scheme 54: (A) Known anticancer natural isoquinoline derivatives; (B and C) cobalt-catalyzed C(sp2)–H annulati...
Scheme 55: (A) Enantioselective intramolecular nickel-catalyzed C–H activation; (B) bioactive obtained motifs;...
Scheme 56: (A and B) Nickel-catalyzed α-C(sp3)–H arylation of ketones; (C) application of the method using kno...
Scheme 57: (A and B) Nickel-catalyzed C(sp3)–H acylation of pyrrolidine derivatives; (C) exploring the use of ...
Scheme 58: (A) Nickel-catalyzed C(sp3)–H arylation of dioxolane; (B) library of products obtained from biologi...
Scheme 59: (A) Intramolecular enantioselective nickel-catalyzed C–H cycloalkylation; (B) product examples, inc...
Scheme 60: (A and B) Nickel-catalyzed C–H deoxy-arylation of azole derivatives; (C) late-stage functionalizati...
Scheme 61: (A and B) Nickel-catalyzed decarbonylative C–H arylation of azole derivatives; (C) application of t...
Scheme 62: (A and B) Another important example of nickel-catalyzed C–H arylation of azole derivatives; (C) app...
Scheme 63: (A and B) Another notable example of a nickel-catalyzed C–H arylation of azole derivatives; (C) lat...
Scheme 64: (A and B) Nickel-based metalorganic framework (MOF-74-Ni)-catalyzed C–H arylation of azole derivati...
Scheme 65: (A) Known commercially available benzothiophene-based drugs; (B and C) nickel-catalyzed C–H arylati...
Scheme 66: (A) Known natural tetrahydrofuran-containing substances; (B and C) nickel-catalyzed photoredox C(sp3...
Scheme 67: (A and B) Another notable example of a nickel-catalyzed photoredox C(sp3)–H alkylation/arylation; (...
Scheme 68: (A) Electrochemical/nickel-catalyzed C–H alkoxylation; (B) achieved scope, including three using na...
Scheme 69: (A) Enantioselective photoredox/nickel catalyzed C(sp3)–H arylation; (B) achieved scope, including ...
Scheme 70: (A) Known commercially available trifluoromethylated drugs; (B and C) nickel-catalyzed C–H trifluor...
Scheme 71: (A and B) Stereoselective nickel-catalyzed C–H difluoroalkylation; (C) late-stage functionalization...
Scheme 72: (A) Cu-mediated ortho-amination of oxalamides; (B) achieved scope, including derivatives obtained f...
Scheme 73: (A) Electro-oxidative copper-mediated amination of 8-aminoquinoline-derived amides; (B) achieved sc...
Scheme 74: (A and B) Cu(I)-mediated C–H amination with oximes; (C) derivatization using telmisartan (241) as s...
Scheme 75: (A and B) Cu-mediated amination of aryl amides using ammonia; (C) late-stage modification of proben...
Scheme 76: (A and B) Synthesis of purine nucleoside analogues using copper-mediated C(sp2)–H activation.
Scheme 77: (A) Copper-mediated annulation of acrylamide; (B) achieved scope, including the synthesis of the co...
Scheme 78: (A) Known bioactive compounds containing a naphthyl aryl ether motif; (B and C) copper-mediated eth...
Scheme 79: (A and B) Cu-mediated alkylation of N-oxide-heteroarenes; (C) late-stage modification.
Scheme 80: (A) Cu-mediated cross-dehydrogenative coupling of polyfluoroarenes and alkanes; (B) scope from know...
Scheme 81: (A) Known anticancer acrylonitrile compounds; (B and C) Copper-mediated cyanation of unactivated al...
Scheme 82: (A) Cu-mediated radiofluorination of 8-aminoquinoline-derived aryl amides; (B) achieved scope, incl...
Scheme 83: (A) Examples of natural β-carbolines; (B and C) an example of a zinc-catalyzed C–H functionalizatio...
Scheme 84: (A) Examples of anticancer α-aminophosphonic acid derivatives; (B and C) an example of a zinc-catal...
Beilstein J. Org. Chem. 2021, 17, 1464–1475, doi:10.3762/bjoc.17.102
Graphical Abstract
Figure 1: Diindolylmethanes and reported biological activities.
Figure 2: Synthetic strategies toward trifluoromethylated unsymmetrical quaternary DIMs.
Figure 3: Reactions performed to study the scope of the method.
Figure 4: Gram-scale synthesis of unsymmetrical DIMs 3a and 3ad.
Figure 5: Plausible reaction mechanism for the synthesis of fluoromethylated unsymmetrical DIMs, shown for co...
Beilstein J. Org. Chem. 2021, 17, 964–976, doi:10.3762/bjoc.17.78
Graphical Abstract
Scheme 1: Scope of glycosyl acceptors for glycosylation with pivaloyl-protected mannosyl fluoride α-1a in liq...
Scheme 2: Glycosylation of binucleophiles 7a,b in liquid SO2.
Scheme 3: Pivaloyl-protected glucosyl fluoride β-9 as a glycosyl donor in liquid SO2.
Scheme 4: Benzyl protected manno- and glucopyranosyl fluorides α-15 and 16 as glycosyl donors in liquid SO2. ...
Scheme 5: 2-Deoxy glycosyl fluoride α-19 as a glycosyl donor in liquid SO2.
Figure 1: Detection of the FSO2− species by 19F NMR (471 MHz, D2O).
Figure 2: Computational study of reaction mechanism α-11 + MeOH → α-13c in the presence of and in absence of ...
Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32
Graphical Abstract
Figure 1: Stabilizing interaction in the CF3CH2+ carbenium ion (top) and structure of the first observable fl...
Scheme 1: Isodesmic equations accounting for the destabilizing effect of the CF3 group. ΔE in kcal⋅mol−1, cal...
Scheme 2: Stabilizing effect of fluorine atoms by resonance electron donation in carbenium ions (δ in ppm).
Scheme 3: Direct in situ NMR observation of α-(trifluoromethyl)carbenium ion or protonated alcohols. Δδ = δ19...
Scheme 4: Reported 13C NMR chemical shifts for the α-(trifluoromethyl)carbenium ion 10c (δ in ppm).
Scheme 5: Direct NMR observation of α-(trifluoromethyl)carbenium ions in situ (δ in ppm).
Scheme 6: Illustration of the ion pair solvolysis mechanism for sulfonate 13f. YOH = solvent.
Figure 2: Solvolysis rate for 13a–i and 17.
Figure 3: Structures of allyl triflates 18 and 19 and allyl brosylate 20. Bs = p-BrC6H4SO2.
Figure 4: Structure of tosylate derivatives 21.
Figure 5: a) Structure of triflate derivatives 22. b) Stereochemistry outcomes of the reaction starting from (...
Scheme 7: Solvolysis reaction of naphthalene and anthracenyl derivatives 26 and 29.
Figure 6: Structure of bisarylated derivatives 34.
Figure 7: Structure of bisarylated derivatives 36.
Scheme 8: Reactivity of 9c in the presence of a Brønsted acid.
Scheme 9: Cationic electrocyclization of 38a–c under strongly acidic conditions.
Scheme 10: Brønsted acid-catalyzed synthesis of indenes 42 and indanes 43.
Scheme 11: Reactivity of sulfurane 44 in triflic acid.
Scheme 12: Solvolysis of triflate 45f in alcoholic solvents.
Scheme 13: Synthesis of labeled 18O-52.
Scheme 14: Reactivity of sulfurane 53 in triflic acid.
Figure 8: Structure of tosylates 56 and 21f.
Scheme 15: Resonance forms in benzylic carbenium ions.
Figure 9: Structure of pyrrole derivatives 58 and 59.
Scheme 16: Resonance structure 60↔60’.
Scheme 17: Ga(OTf)3-catalyzed synthesis of 3,3’- and 3,6’-bis(indolyl)methane from trifluoromethylated 3-indol...
Scheme 18: Proposed reaction mechanism.
Scheme 19: Metal-free 1,2-phosphorylation of 3-indolylmethanols.
Scheme 20: Superacid-mediated arylation of thiophene derivatives.
Scheme 21: In situ mechanistic NMR investigations.
Scheme 22: Proposed mechanisms for the prenyltransferase-catalyzed condensation.
Scheme 23: Influence of a CF3 group on the allylic SN1- and SN2-mechanism-based reactions.
Scheme 24: Influence of the CF3 group on the condensation reaction.
Scheme 25: Solvolysis of 90 in TFE.
Scheme 26: Solvolysis of allyl triflates 94 and 97 and isomerization attempt of 96.
Scheme 27: Proposed mechanism for the formation of 95.
Scheme 28: Formation of α-(trifluoromethyl)allylcarbenium ion 100 in a superacid.
Scheme 29: Lewis acid activation of CF3-substituted allylic alcohols.
Scheme 30: Bimetallic-cluster-stabilized α-(trifluoromethyl)carbenium ions.
Scheme 31: Reactivity of cluster-stabilized α-(trifluoromethyl)carbenium ions.
Scheme 32: α-(Trifluoromethyl)propargylium ion 122↔122’ generated from silyl ether 120 in a superacid.
Scheme 33: Formation of α-(trifluoromethyl)propargylium ions from CF3-substituted propargyl alcohols.
Scheme 34: Direct NMR observation of the protonation of some trifluoromethyl ketones in situ and the correspon...
Scheme 35: Selected resonance forms in protonated fluoroketone derivatives.
Scheme 36: Acid-catalyzed Friedel–Crafts reactions of trifluoromethyl ketones 143a,b and 147a–c.
Scheme 37: Enantioselective hydroarylation of CF3-substituted ketones.
Scheme 38: Acid-catalyzed arylation of ketones 152a–c.
Scheme 39: Reactivity of 156 in a superacid.
Scheme 40: Reactivity of α-CF3-substituted heteroaromatic ketones and alcohols as well as 1,3-diketones.
Scheme 41: Reactivity of 168 with benzene in the presence of a Lewis or Brønsted acid.
Scheme 42: Acid-catalyzed three-component asymmetric reaction.
Scheme 43: Anodic oxidation of amines 178a–c and proposed mechanism.
Scheme 44: Reactivity of 179b in the presence of a strong Lewis acid.
Scheme 45: Trifluoromethylated derivatives as precursors of trifluoromethylated iminium ions.
Scheme 46: Mannich reaction with trifluoromethylated hemiaminal 189.
Scheme 47: Suitable nucleophiles reacting with 192 after Lewis acid activation.
Scheme 48: Strecker reaction involving the trifluoromethylated iminium ion 187.
Scheme 49: Reactivity of 199 toward nucleophiles.
Scheme 50: Reactivity of 204a with benzene in the presence of a Lewis acid.
Scheme 51: Reactivity of α-(trifluoromethyl)-α-chloro sulfides in the presence of strong Lewis acids.
Scheme 52: Anodic oxidation of sulfides 213a–h and Pummerer rearrangement.
Scheme 53: Mechanism for the electrochemical oxidation of the sulfide 213a.
Scheme 54: Reactivity of (trifluoromethyl)diazomethane (217a) in HSO3F.
Figure 10: a) Structure of diazoalkanes 217a–c and b) rate-limiting steps of their decomposition.
Scheme 55: Deamination reaction of racemic 221 and enantioenriched (S)-221.
Scheme 56: Deamination reaction of labeled 221-d2. Elimination products were formed in this reaction, the yiel...
Scheme 57: Deamination reaction of 225-d2. Elimination products were also formed in this reaction in undetermi...
Scheme 58: Formation of 229 from 228 via 1,2-H-shift.
Scheme 59: Deamination reaction of 230. Elimination products were formed in this reaction, the yield of which ...
Scheme 60: Deamination of several diazonium ions. Elimination products were formed in these reactions, the yie...
Scheme 61: Solvolysis reaction mechanism of alkyl tosylates.
Scheme 62: Solvolysis outcome for the tosylates 248 and 249 in HSO3FSbF5.
Figure 11: Solvolysis rate of 248, 249, 252, and 253 in 91% H2SO4.
Scheme 63: Illustration of the reaction pathways. TsCl, pyridine, −5 °C (A); 98% H2SO4, 30 °C (B); 98% H2SO4, ...
Scheme 64: Proposed solvolysis mechanism for the aliphatic tosylate 248.
Scheme 65: Solvolysis of the derivatives 259 and 260.
Scheme 66: Solvolysis of triflate 261. SOH = solvent.
Scheme 67: Intramolecular Friedel–Crafts alkylations upon the solvolysis of triflates 264 and 267.
Scheme 68: α-CF3-enhanced γ-silyl elimination of cyclobutyltosylates 270a,b.
Scheme 69: γ-Silyl elimination in the synthesis of a large variety of CF3-substituted cyclopropanes. Pf = pent...
Scheme 70: Synthetic pathways to 281. aNMR yields.
Scheme 71: The cyclopropyl-substituted homoallylcyclobutylcarbenium ion manifold.
Scheme 72: Reactivity of CF3-substituted cyclopropylcarbinyl derivatives 287a–c. LG = leaving group.
Scheme 73: Reactivity of CF3-substituted cyclopropylcarbinyl derivatives 291a–c.
Scheme 74: Superacid-promoted dimerization or TFP.
Scheme 75: Reactivity of TFP in a superacid.
Scheme 76: gem-Difluorination of α-fluoroalkyl styrenes via the formation of a “hidden” α-RF-substituted carbe...
Scheme 77: Solvolysis of CF3-substituted pentyne 307.
Scheme 78: Photochemical rearrangement of 313.
Figure 12: Structure of 2-norbornylcarbenium ion 318 and argued model for the stabilization of this cation.
Figure 13: Structures and solvolysis rate (TFE, 25 °C) of the sulfonates 319–321. Mos = p-MeOC6H4SO2.
Scheme 79: Mechanism for the solvolysis of 323. SOH = solvent.
Scheme 80: Products formed by the hydrolysis of 328.
Scheme 81: Proposed carbenium ion intermediates in an equilibrium during the solvolysis of tosylates 328, 333,...
Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25
Graphical Abstract
Scheme 1: Synthesis of 1,1-difluoro-2,3-dimethylcyclopropane (2).
Scheme 2: Cyclopropanation via dehydrohalogenation of chlorodifluoromethane.
Scheme 3: Difluorocyclopropanation of methylstyrene 7 using dibromodifluoromethane and zinc.
Scheme 4: Synthesis of difluorocyclopropanes from the reaction of dibromodifluoromethane and triphenylphosphi...
Scheme 5: Generation of difluorocarbene in a catalytic two-phase system and its addition to tetramethylethyle...
Scheme 6: The reaction of methylstyrene 7 with chlorodifluoromethane (11) in the presence of a tetraarylarson...
Scheme 7: Pyrolysis of sodium chlorodifluoroacetate (12) in refluxing diglyme in the presence of alkene 13.
Scheme 8: Synthesis of boron-substituted gem-difluorocyclopropanes 16.
Scheme 9: Addition of sodium bromodifluoroacetate (17) to alkenes.
Scheme 10: Addition of sodium bromodifluoroacetate (17) to silyloxy-substituted cyclopropanes 20.
Scheme 11: Synthesis of difluorinated nucleosides.
Scheme 12: Addition of butyl acrylate (26) to difluorocarbene generated from TFDA (25).
Scheme 13: Addition of difluorocarbene to propargyl esters 27 and conversion of the difluorocyclopropenes 28 t...
Scheme 14: The generation of difluorocyclopropanes using MDFA 30.
Scheme 15: gem-Difluorocyclopropanation of styrene (32) using difluorocarbene generated from TMSCF3 (31) under...
Scheme 16: Synthesis of a gem-difluorocyclopropane derivative using HFPO (41) as a source of difluorocarbene.
Scheme 17: Cyclopropanation of (Z)-2-butene in the presence of difluorodiazirine (44).
Scheme 18: The cyclopropanation of 1-octene (46) using Seyferth's reagent (45) as a source of difluorocarbene.
Scheme 19: Alternative approaches for the difluorocarbene synthesis from trimethyl(trifluoromethyl)tin (48).
Scheme 20: Difluorocyclopropanation of cyclohexene (49).
Scheme 21: Synthesis of difluorocyclopropane derivative 53 using bis(trifluoromethyl)cadmium (51) as the diflu...
Scheme 22: Addition of difluorocarbene generated from tris(trifluoromethyl)bismuth (54).
Scheme 23: Addition of a stable (trifluoromethyl)zinc reagent to styrenes.
Scheme 24: The preparation of 2,2-difluorocyclopropanecarboxylic acids of type 58.
Scheme 25: Difluorocyclopropanation via Michael cyclization.
Scheme 26: Difluorocyclopropanation using N-acylimidazolidinone 60.
Scheme 27: Difluorocyclopropanation through the cyclization of phenylacetonitrile (61) and 1,2-dibromo-1,1-dif...
Scheme 28: gem-Difluoroolefins 64 for the synthesis of functionalized cyclopropanes 65.
Scheme 29: Preparation of aminocyclopropanes 70.
Scheme 30: Synthesis of fluorinated methylenecyclopropane 74 via selenoxide elimination.
Scheme 31: Reductive dehalogenation of (1R,3R)-75.
Scheme 32: Synthesis of chiral monoacetates by lipase catalysis.
Scheme 33: Transformation of (±)-trans-81 using Rhodococcus sp. AJ270.
Scheme 34: Transformation of (±)-trans-83 using Rhodococcus sp. AJ270.
Scheme 35: Hydrogenation of difluorocyclopropenes through enantioselective hydrocupration.
Scheme 36: Enantioselective transfer hydrogenation of difluorocyclopropenes with a Ru-based catalyst.
Scheme 37: The thermal transformation of trans-1,2-dichloro-3,3-difluorocyclopropane (84).
Scheme 38: cis–trans-Epimerization of 1,1-difluoro-2,3-dimethylcyclopropane.
Scheme 39: 2,2-Difluorotrimethylene diradical intermediate.
Scheme 40: Ring opening of stereoisomers 88 and 89.
Scheme 41: [1,3]-Rearrangement of alkenylcyclopropanes 90–92.
Scheme 42: Thermolytic rearrangement of 2,2-difluoro-1-vinylcyclopropane (90).
Scheme 43: Thermal rearrangement for ethyl 3-(2,2-difluoro)-3-phenylcyclopropyl)acrylates 93 and 95.
Scheme 44: Possible pathways of the ring opening of 1,1-difluoro-2-vinylcyclopropane.
Scheme 45: Equilibrium between 1,1-difluoro-2-methylenecyclopropane (96) and (difluoromethylene)cyclopropane 97...
Scheme 46: Ring opening of substituted 1,1-difluoro-2,2-dimethyl-3-methylenecyclopropane 98.
Scheme 47: 1,1-Difluorospiropentane rearrangement.
Scheme 48: Acetolysis of (2,2-difluorocyclopropyl)methyl tosylate (104) and (1,1-difluoro-2-methylcyclopropyl)...
Scheme 49: Ring opening of gem-difluorocyclopropyl ketones 106 and 108 by thiolate nucleophiles.
Scheme 50: Hydrolysis of gem-difluorocyclopropyl acetals 110.
Scheme 51: Ring-opening reaction of 2,2-difluorocyclopropyl ketones 113 in the presence of ionic liquid as a s...
Scheme 52: Ring opening of gem-difluorocyclopropyl ketones 113a by MgI2-initiated reaction with diarylimines 1...
Scheme 53: Ring-opening reaction of gem-difluorocyclopropylstannanes 117.
Scheme 54: Preparation of 1-fluorovinyl vinyl ketone 123 and the synthesis of 2-fluorocyclopentenone 124. TBAT...
Scheme 55: Iodine atom-transfer ring opening of 1,1-difluoro-2-(1-iodoalkyl)cyclopropanes 125a–c.
Scheme 56: Ring opening of bromomethyl gem-difluorocyclopropanes 130 and formation of gem-difluoromethylene-co...
Scheme 57: Ring-opening aerobic oxidation reaction of gem-difluorocyclopropanes 132.
Scheme 58: Dibrominative ring-opening functionalization of gem-difluorocyclopropanes 134.
Scheme 59: The selective formation of (E,E)- and (E,Z)-fluorodienals 136 and 137 from difluorocyclopropyl acet...
Scheme 60: Proposed mechanism for the reaction of difluoro(methylene)cyclopropane 139 with Br2.
Scheme 61: Thermal rearrangement of F2MCP 139 and iodine by CuI catalysis.
Scheme 62: Synthesis of 2-fluoropyrroles 142.
Scheme 63: Ring opening of gem-difluorocyclopropyl ketones 143 mediated by BX3.
Scheme 64: Lewis acid-promoted ring-opening reaction of 2,2-difluorocyclopropanecarbonyl chloride (148).
Scheme 65: Ring-opening reaction of the gem-difluorocyclopropyl ketone 106 by methanolic KOH.
Scheme 66: Hydrogenolysis of 1,1-difluoro-3-methyl-2-phenylcyclopropane (151).
Scheme 67: Synthesis of monofluoroalkenes 157.
Scheme 68: The stereoselective Ag-catalyzed defluorinative ring-opening diarylation of 1-trimethylsiloxy-2,2-d...
Scheme 69: Synthesis of 2-fluorinated allylic compounds 162.
Scheme 70: Pd-catalyzed cross-coupling reactions of gem-difluorinated cyclopropanes 161.
Scheme 71: The (Z)-selective Pd-catalyzed ring-opening sulfonylation of 2-(2,2-difluorocyclopropyl)naphthalene...
Figure 1: Structures of zosuquidar hydrochloride and PF-06700841.
Scheme 72: Synthesis of methylene-gem-difluorocyclopropane analogs of nucleosides.
Figure 2: Anthracene-difluorocyclopropane hybrid derivatives.
Figure 3: Further examples of difluorcyclopropanes in modern drug discovery.
Beilstein J. Org. Chem. 2020, 16, 2880–2887, doi:10.3762/bjoc.16.237
Graphical Abstract
Figure 1: Previously described synthesis of 2,3,4-trifluorinated analogues of galactose 6, glucose 7, mannose ...
Figure 2: Typical 19F NMR spectrum (470 MHz, CDCl3) of the crude reaction mixture using Et3N·3HF/Et3N (entry ...
Figure 3: Fluorination at C4 of 1,6-anhydro-2,3-difluorohexopyranose analogues. a) Reactions on triflates 13, ...
Scheme 1: Synthesis of polyfluorinated alditols from levoglucosan 1: a) difluoroglucitol analogue 22; b) trif...
Beilstein J. Org. Chem. 2020, 16, 2663–2670, doi:10.3762/bjoc.16.216
Graphical Abstract
Figure 1: The natural product piperine (1) is the inspiration for this work; the crystal structure is shown [14]....
Scheme 1: The attempted synthesis of 6 (a diastereoisomer of 2) via a one-step 1,2-difluorination reaction [24]. ...
Scheme 2: The attempted synthesis of 2 via a stepwise fluorination approach (ether series). THF = tetrahydrof...
Scheme 3: Synthesis of compound 2 via a stepwise fluorination approach (ester series). DIC = diisopropylcarbo...
Figure 2: Conformational analysis of 2 by DFT and NMR. The numbering scheme for NMR spins is given on structu...
Figure 3: Analog 2 has greater stability to UV light than does piperine (1).
Figure 4: Biological activity of piperine (1) and derivative 2. (a) Inihbition of AChE by 1 (IC50 >1000 μM) a...
Beilstein J. Org. Chem. 2020, 16, 2623–2635, doi:10.3762/bjoc.16.213
Graphical Abstract
Scheme 1: Reactivity of tetrafluoropropanes HFO-1234yf (1) (top) and HFO-1234ze (4a) (bottom) in the presence...
Scheme 2: Reactivity of 10a in the presence of ACF as the catalyst in C6D12 (top) or C6D6 (bottom) as solvent...
Scheme 3: Proposed catalytic cycle of the transformation of 10a in C6D12 and C6D6 in the presence of ACF as t...
Scheme 4: Reactivity of 10a in the presence of ACF as the catalyst and HSiEt3 as a hydrogen source in C6D12 (...
Scheme 5: Proposed catalytic cycle for sylilium-mediated hydrodefluorinations and dehydrofluorinations from 1...
Scheme 6: Reactivity of 13 in the presence of ACF as the catalyst, with (top) or without (bottom) HSiEt3 as a...
Scheme 7: Independent reactions starting from 5, 6, or 14 in the presence of ACF as the catalyst.
Scheme 8: Proposed reaction pathways starting from 10a in the presence of ACF and silane.
Scheme 9: Reactivity of 10c in the presence of ACF as the catalyst and 0.5 equivalents of HSiEt3 as a hydroge...
Scheme 10: Proposed catalytic cycles for the transformation of 10c in C6D12 and in the presence of 0.5 equival...
Scheme 11: Reactivity of 10c in the presence of ACF as the catalyst and HSiEt3 as a hydrogen source in C6D12 (...
Scheme 12: Proposed reaction pathways starting from 10c in the presence of ACF and silane.
Scheme 13: Reactivity of 10b in the presence of ACF as the catalyst and HSiEt3 as a hydrogen source in C6D12 (...
Scheme 14: Proposed reaction pathway starting from 10b in the presence of ACF and silane.
Beilstein J. Org. Chem. 2020, 16, 2469–2476, doi:10.3762/bjoc.16.200
Graphical Abstract
Figure 1: Chemical structure of penoxsulam (I) and the main staggered conformations along the two F–C–C–O tor...
Figure 2: Optimized structures of conformers Igg (left), Iag (middle), and Iga (right), along with the relati...
Figure 3: Energy profile for the rotation around the C–C(F) bond and NBO analysis project onto the φO–C–C–H t...
Figure 4: Chemical structure of the agrochemicals I–VII analyzed herein.
Figure 5: Correlation between the experimental log P of agrochemicals I–VII and a) dipole moment (for I, μ is...
Figure 6: Chemical structure of the compounds 1–11 analyzed herein.
Figure 7: Correlation between the experimental log P of compounds 1–11 and a) dipole moment (for 7, 9, and 10...
Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183
Graphical Abstract
Figure 1: Fluorine-containing drugs.
Figure 2: Fluorinated agrochemicals.
Scheme 1: Selectivity of fluorination reactions.
Scheme 2: Different mechanisms of photocatalytic activation. Sub = substrate.
Figure 3: Jablonski diagram showing visible-light-induced energy transfer pathways: a) absorption, b) IC, c) ...
Figure 4: Schematic illustration of TTET.
Figure 5: Organic triplet PSCats.
Figure 6: Additional organic triplet PSCats.
Figure 7: A) Further organic triplet PSCats and B) transition metal triplet PSCats.
Figure 8: Different fluorination reagents grouped by generation.
Scheme 3: Synthesis of Selectfluor®.
Scheme 4: General mechanism of PS TTET C(sp3)–H fluorination.
Scheme 5: Selective benzylic mono- and difluorination using 9-fluorenone and xanthone PSCats, respectively.
Scheme 6: Chen’s photosensitized monofluorination: reaction scope.
Scheme 7: Chen’s photosensitized benzylic difluorination reaction scope.
Scheme 8: Photosensitized monofluorination of ethylbenzene on a gram scale.
Scheme 9: Substrate scope of Tan’s AQN-photosensitized C(sp3)–H fluorination.
Scheme 10: AQN-photosensitized C–H fluorination reaction on a gram scale.
Scheme 11: Reaction mechanism of the AQN-assisted fluorination.
Figure 9: 3D structures of the singlet ground and triplet excited states of Selectfluor®.
Scheme 12: Associated transitions for the activation of acetophenone by violet light.
Scheme 13: Ethylbenzene C–H fluorination with various PSCats and conditions.
Scheme 14: Effect of different PSCats on the C(sp3)–H fluorination of cyclohexane (39).
Scheme 15: Reaction scope of Chen’s acetophenone-photosensitized C(sp3)–H fluorination reaction.
Figure 10: a) Site-selectivity of Chen’s acetophenone-photosensitized C–H fluorination reaction [201]. b) Site-sele...
Scheme 16: Formation of the AQN–Selectfluor® exciplex Int1.
Scheme 17: Generation of the C3 2° pentane radical and the Selectfluor® N-radical cation from the exciplex.
Scheme 18: Hydrogen atom abstraction by the Selectfluor® N-radical cation from pentane to give the C3 2° penta...
Scheme 19: Fluorine atom transfer from Selectfluor® to the C3 2° pentane radical to yield 3-fluoropentane and ...
Scheme 20: Barrierless fluorine atom transfer from Int1 to the C3 2° pentane radical to yield 3-fluoropentane,...
Scheme 21: Ketone-directed C(sp3)–H fluorination.
Scheme 22: Ketone-directed fluorination through a 5- and a 6-membered transition state, respectively.
Scheme 23: Effect of different PSCats on the photosensitized C(sp3)–H fluorination of 47.
Scheme 24: Substrate scope of benzil-photoassisted C(sp3)–H fluorinations.
Scheme 25: A) Benzil-photoassisted enone-directed C(sp3)–H fluorination. B) Classification of the reaction mod...
Scheme 26: A) Xanthone-photoassisted ketal-directed C(sp3)–H fluorination. B) Substrate scope. C) C–H fluorina...
Scheme 27: Rationale for the selective HAT at the C2 C–H bond of galactose acetonide.
Scheme 28: Photosensitized C(sp3)–H benzylic fluorination of a peptide using different PSCats.
Scheme 29: Peptide scope of 5-benzosuberenone-photoassisted C(sp3)–H fluorinations.
Scheme 30: Continuous flow PS TTET monofluorination of 72.
Scheme 31: Photosensitized C–H fluorination of N-butylphthalimide as a PSX.
Scheme 32: Substrate scope and limitations of the PSX C(sp3)–H monofluorination.
Scheme 33: Substrate crossover monofluorination experiment.
Scheme 34: PS TTET mechanism proposed by Hamashima and co-workers.
Scheme 35: Photosensitized TFM of 78 to afford α-trifluoromethylated ketone 80.
Scheme 36: Substrate scope for photosensitized styrene TFM to give α-trifluoromethylated ketones.
Scheme 37: Control reactions for photosensitized TFM of styrenes.
Scheme 38: Reaction mechanism for photosensitized TFM of styrenes to afford α-trifluoromethylated ketones.
Scheme 39: Reaction conditions for TFMs to yield the cis- and the trans-product, respectively.
Scheme 40: Substrate scope of trifluoromethylated (E)-styrenes.
Scheme 41: Strategies toward trifluoromethylated (Z)-styrenes.
Scheme 42: Substrate scope of trifluoromethylated (Z)-styrenes.
Scheme 43: Reaction mechanism for photosensitized TFM of styrenes to afford E- or Z-products.
Beilstein J. Org. Chem. 2020, 16, 2141–2150, doi:10.3762/bjoc.16.182
Graphical Abstract
Figure 1: Examples of lipophilicity modulation for geminal dimethyl to cyclopropyl and oxetane modifications ...
Figure 2: Lipophilicity modulation examples involving fluorinated cyclopropane derivatives (measured experime...
Figure 3: Lipophilicity changes upon fluorination of isopropyl, cyclopropane and oxetane rings (Series A, C: ...
Figure 4: Lipophilicity modulations discussed in this contribution.
Figure 5: Distribution of the experimental lipophilicity values of series D, E and F (* denotes an estimated ...
Figure 6: Comparison of lipophilicities between the linear alkyl, isopropyl, cyclopropyl, and 3-oxetanyl subs...
Figure 7: Comparison of lipophilicities between isopropyl and cyclopropyl substituents grouped by exchange of...
Figure 8: Carbon extensions.
Figure 9: Experimental and theoretical (in blue) values (calculated at the MN15/aug-cc-pVTZ//MN15/cc-pVTZ lev...
Figure 10: Correlation of the DFT-calculated lipophilicities with the experimental values. A) fluorinated seri...
Figure 11: Experimental (in black) and theoretical (in blue) values (calculated at the MN15/aug-cc-pVTZ//MN15/...
Beilstein J. Org. Chem. 2020, 16, 2064–2072, doi:10.3762/bjoc.16.173
Graphical Abstract
Scheme 1: Diels–Alder reaction of propyn-1-iminium salt 1a compared with the reported [29] reaction of 4-phenyl-1...
Scheme 2: Sequential Diels–Alder/intramolecular SE(Ar) reaction of propyn-1-iminium triflates 1a,b. Condition...
Scheme 3: Diels–Alder reaction of 1a and anthracene followed by an intramolecular SE(Ar) reaction.
Figure 1: Solid-state molecular structure of 11 (ORTEP plot).
Scheme 4: Reactions of propyn-1-iminium salt 1a with styrenes.
Figure 2: Solid-state molecular structure of 12c (ORTEP plot).
Figure 3: Solid-state molecular structure of 12d (ORTEP plot). Both the R and the S enantiomer are present in...
Scheme 5: A mechanistic proposal for the reaction of alkyne 1a with styrenes.
Scheme 6: Reaction of alkyne 1a with 1,2-dihydronaphthalene.
Scheme 7: Synthesis and solid-state molecular structure (ORTEP plot) of pentafulvene 19; selected bond distan...
Scheme 8: Proposed mechanistic pathway leading to fulvene 19.
Beilstein J. Org. Chem. 2020, 16, 1837–1852, doi:10.3762/bjoc.16.151
Graphical Abstract
Figure 1: A) Three types of the backbone amino acid structures that are included in protein translation: glyc...
Figure 2: The set of amino acids examined in this study.
Figure 3: Design of the model system.
Figure 4: Propagation of the C4-conformation into the values of the J coupling in the C2H–C3H2 fragments.
Figure 5: Preferred side-chain conformations according to the multiplicity data.
Figure 6: A) The basicity reduction from the introduction of the dipoles reflects the preferred conformation ...
Figure 7: The lipophilicity data of the model compounds.
Figure 8: The expectations regarding the amide-bond rotation preferences in 1–4.
Figure 9: The explanation for the difference in the rotation barriers in the diastereomeric (A), 4-(trifluoro...
Figure 10: A) The structures of difluorinated model compounds 5 and 6, and the fluorine-free reference 7. B) B...