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Search for "organolithium reagents" in Full Text gives 29 result(s) in Beilstein Journal of Organic Chemistry.
Meta-metallation of N,N-dimethylaniline: Contrasting direct sodium-mediated zincation with indirect sodiation-dialkylzinc co-complexation
- David R. Armstrong,
- Liam Balloch,
- Eva Hevia,
- Alan R. Kennedy,
- Robert E. Mulvey,
- Charles T. O'Hara and
- Stuart D. Robertson
Beilstein J. Org. Chem. 2011, 7, 1234–1248, doi:10.3762/bjoc.7.144
- capable of selectively abstracting hydrogen from organic substrates continues. Routinely, organolithium reagents have been employed for this purpose with the high electropositivity of lithium affording polar, reactive Cδ−–Liδ+ bonds proficient in metallating C–H bonds in organic, especially aromatic and
Graphical Abstract
Scheme 1: Proposed stepwise mechanism for the zincation of benzene.
Figure 1: Molecular structure of 2 with selective atom labelling. Hydrogen atoms and minor disorder component...
Scheme 2: Synergic metallation of N,N-dimethylaniline (A) with sodium TMP-zincate 1 to produce 2, which was s...
Figure 2: Molecular structure of 3 with selective atom labelling and thermal ellipsoids drawn at the 50% prob...
Scheme 3: Indirect zincation of N,N-dimethylaniline producing 4, 5 and 6, which was then quenched with I2 to ...
Figure 3: Molecular structure of 4 with selective atom labelling and thermal ellipsoids drawn at the 50% prob...
Figure 4: Solvent-separated ion-pair structure of 5 with selective atom labelling and thermal ellipsoids draw...
Figure 5: Molecular structure of 6 with selective atom labelling and thermal ellipsoids drawn at the 50% prob...
Figure 6: Aromatic region of 1H NMR spectra for deuterated benzene solutions of (a) the crude mixture obtaine...
Figure 7: Relative energy sequence of the four theoretical regioisomers of the experimentally observed produc...
α,β-Aziridinylphosphonates by lithium amide-induced phosphonyl migration from nitrogen to carbon in terminal aziridines
- David. M. Hodgson and
- Zhaoqing Xu
Beilstein J. Org. Chem. 2010, 6, 978–983, doi:10.3762/bjoc.6.110
- substrate 1a (57%, Scheme 4) [28]. Initially, we examined organolithiums for their propensity to induce deprotonation-migration in N-phosphonate aziridine 1a. Despite it being previously noted by Zwierzak that the reaction of organolithium reagents with such substrates resulted in preferential attack at
Graphical Abstract
Scheme 1: Proposed aziridinyl anion induced N- to C-phosphonyl migration.
Scheme 2: Selected previously observed N- to C-phosphorous migrations [17,18,21].
Scheme 3: Partial N- to C-migration with N-diphenylphosphinylaziridine 10 [24].
Scheme 4: Synthesis and rearrangement of aziridine 1a.
Figure 1: Aziridines 1h–j.
Scheme 5: Synthesis and rearrangement of aziridine (S)-1k.
Scheme 6: Hydrogenolysis of aziridinylphosphonate (–)-3k.
Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation
- Vladimir N. Boiko
Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88
Graphical Abstract
Figure 1: Examples of industrial fluorine-containing bio-active molecules.
Figure 2: CF3(S)- and CF3(O)-containing pharmacologically active compounds.
Figure 3: Hypotensive candidates with SRF and SO2RF groups – analogues of Losartan and Nifedipin.
Figure 4: The variety of the pharmacological activity of RFS-substituted compounds.
Figure 5: Recent examples of compounds containing RFS(O)n-groups [12-18].
Scheme 1: Fluorination of ArSCCl3 to corresponding ArSCF3 derivatives. For references see: a[38-43]; b[41,42]; c[43]; d[44]; e[38-43,45-47]; f[38-43,48,49]; g...
Scheme 2: Preparation of aryl pentafluoroethyl sulfides.
Scheme 3: Mild fluorination of the aryl SCF2Br derivatives.
Scheme 4: HF fluorinations of aryl α,α,β-trichloroisobutyl sulfide at various conditions.
Scheme 5: Monofluorination of α,α-dichloromethylene group.
Scheme 6: Electrophilic substitution of phenols with CF3SCl [69].
Scheme 7: Introduction of SCF3 groups into activated phenols [71-74].
Scheme 8: Preparation of tetrakis(SCF3)-4-methoxyphenol [72].
Scheme 9: The interactions of resorcinol and phloroglucinol derivatives with RFSCl.
Scheme 10: Reactions of anilines with CF3SCl.
Scheme 11: Trifluoromethylsulfanylation of anilines with electron-donating groups in the meta position [74].
Scheme 12: Reaction of benzene with CF3SCl/CF3SO3H [77].
Scheme 13: Reactions of trifluoromethyl sulfenyl chloride with aryl magnesium and -mercury substrates.
Scheme 14: Reactions of pyrroles with CF3SCl.
Scheme 15: Trifluoromethylsulfanylation of indole and indolizines.
Scheme 16: Reactions of N-methylpyrrole with CF3SCl [80,82].
Scheme 17: Reactions of furan, thiophene and selenophene with CF3SCl.
Scheme 18: Trifluoromethylsulfanylation of imidazole and thiazole derivatives [83].
Scheme 19: Trifluoromethylsulfanylation of pyridine requires initial hydride reduction.
Scheme 20: Introduction of additional RFS-groups into heterocyclic compounds in the presence of CF3SO3H.
Scheme 21: Introduction of additional RFS-groups into pyrroles [82,87].
Scheme 22: By-products in reactions of pyrroles with CF3SCl [82].
Scheme 23: Reaction of aromatic iodides with CuSCF3 [93,95].
Scheme 24: Reaction of aromatic iodides with RFZCu (Z = S, Se), RF = CF3, C6F5 [93,95,96].
Scheme 25: Side reactions during trifluoromethylsulfanylation of aromatic iodides with CF3SCu [98].
Scheme 26: Reactions with in situ generated CuSCF3.
Scheme 27: Perfluoroalkylthiolation of aryl iodides with bulky RFSCu [105].
Scheme 28: In situ formation and reaction of RFZCu with aryl iodides.
Figure 6: Examples of compounds obtained using in situ generated RFZCu methodology [94].
Scheme 29: Introduction of SCF3 group into aromatics via difluorocarbene.
Scheme 30: Tetrakis(dimethylamino)ethylene dication trifluoromethyl thiolate as a stable reagent for substitut...
Scheme 31: The use of CF2=S/CsF or (CF3S)2C=S/CsF for the introduction of CF3S groups into fluorinated heteroc...
Scheme 32: One-pot synthesis of ArSCF3 from ArX, CCl2=S and KF.
Scheme 33: Reaction of aromatics with CF3S− Kat+ [115].
Scheme 34: Reactions of activated aromatic chlorides with AgSCF3/KI.
Scheme 35: Comparative CuSCF3/KI and Hg(SCF3)2/KI reactions.
Scheme 36: Me3SnTeCF3 – a reagent for the introduction of the TeCF3 group.
Scheme 37: Sandmeyer reactions with CuSCF3.
Scheme 38: Reactions of perfluoroalkyl iodides with alkali and organolithium reagents.
Scheme 39: Perfluoroalkylation with preliminary breaking of the disulfide bond.
Scheme 40: Preparation of RFS-substituted anilines from dinitrodiphenyl disulfides.
Scheme 41: Photochemical trifluoromethylation of 2,4,6-trimercaptochlorobenzene [163].
Scheme 42: Putative process for the formation of B, C and D.
Scheme 43: Trifluoromethylation of 2-mercapto-4-hydroxy-6-trifluoromethylyrimidine [145].
Scheme 44: Deactivation of 2-mercapto-4-hydroxypyrimidines S-centered radicals.
Scheme 45: Perfluoroalkylation of thiolates with CF3Br under UV irradiation.
Scheme 46: Catalytic effect of methylviologen for RF• generation.
Scheme 47: SO2−• catalyzed trifluoromethylation.
Scheme 48: Electrochemical reduction of CF3Br in the presence of SO2 [199,200].
Scheme 49: Participation of SO2 in the oxidation of ArSCF3−•.
Scheme 50: Electron transfer cascade involving SO2 and MV.
Scheme 51: Four stages of the SRN1 mechanism for thiol perfluoroalkylation.
Scheme 52: A double role of MV in the catalysis of RFI reactions with aryl thiols.
Scheme 53: Photochemical reaction of pentafluoroiodobenzene with trifluoromethyl disulfide.
Scheme 54: N- Trifluoromethyl-N-nitrosobenzene sulfonamide – a source of CF3• radicals [212,213].
Scheme 55: Radical trifluoromethylation of organic disulfides with ArSO2N=NCF3.
Scheme 56: Barton’s S-perfluoroalkylation reactions [216].
Scheme 57: Decarboxylation of thiohydroxamic esters in the presence of C6F13I.
Scheme 58: Reactions of thioesters of trifluoroacetic and trifluoromethanesulfonic acids in the presence of ar...
Scheme 59: Perfluoroalkylation of polychloropyridine thiols with xenon perfluorocarboxylates or XeF2 [222,223].
Scheme 60: Interaction of Xe(OCORF)2 with nitroaryl disulfide [227].
Scheme 61: Bi(CF3)3/Cu(OCOCH3)2 trifluoromethylation of thiophenolate [230].
Scheme 62: Reaction of fluorinated carbanions with aryl sulfenyl chlorides.
Scheme 63: Reaction of methyl perfluoromethacrylate with PhSCl in the presence of fluoride.
Scheme 64: Reactions of ArSCN with potassium and magnesium perfluorocarbanions [237].
Scheme 65: Reactions of RFI with TDAE and organic disulfides [239,240].
Scheme 66: Decarboxylation of perfluorocarboxylates in the presence of disulfides [245].
Scheme 67: Organization of a stable form of “CF3−” anion in the DMF.
Scheme 68: Silylated amines in the presence of fluoride can deprotonate fluoroform for reaction with disulfide...
Figure 7: Other examples of aminomethanols [264].
Scheme 69: Trifluoromethylation of diphenyl disulfide with PhSO2CF3/t-BuOK.
Scheme 70: Amides of trifluoromethane sulfinic acid are sources of CF3− anion.
Scheme 71: Trifluoromethylation of various thiols using “hyper-valent” iodine (III) reagent [279].
Scheme 72: Trifluoromethylation of p-nitrothiophenolate with diaryl CF3 sulfonium salts [280].
Scheme 73: Trifluoromethyl transfer from dibenzo (CF3)S-, (CF3)Se- and (CF3)Te-phenium salts to thiolates [283].
Scheme 74: Multi-stage paths for synthesis of dibenzo-CF3-thiophenium salts [61].
An exceptional P-H phosphonite: Biphenyl- 2,2'-bisfenchylchlorophosphite and derived ligands (BIFOPs) in enantioselective copper- catalyzed 1,4-additions
- T. Kop-Weiershausen,
- J. Lex,
- J.-M. Neudörfl and
- B. Goldfuss
Beilstein J. Org. Chem. 2005, 1, No. 6, doi:10.1186/1860-5397-1-6
- recently applied in chiral organolithium reagents [52][53][54][55][56][57][58] and in organozinc [59][60][61][62] as well as in organopalladium catalysts [63][64][65][66][67] to study origins of enantioselectivities in C-C-couplings. The rigid, terpene-based bicyclo[2.2.1]heptane unit enables efficient
Graphical Abstract
Scheme 1: Monodentate phosphorus ligands, e.g. BINOL-based phosphoramidites or TADDOL-based phosphites, are h...
Scheme 2: Modular phosphoramidites (R= NR'2) or phosphites (R= OR') from reactive chlorophosphite intermediat...
Figure 1: X-ray crystal structure of BIFOP-Cl (1). Distances are given in Å. (BAA = biaryl angle between C2-C1...
Figure 2: X-ray structures of BIFOP-Br (2). Distances are given in Å. (BAA = biaryl angle between C2-C1-C1'-C2...
Scheme 3: Synthesis of biphenyl-2,2'-bisfenchol (BIFOL) based phosphane derivatives (BIFOPs).
Figure 3: X-ray structures of BIFOP-H (3). Distances are given in Å. (BAA = biaryl angle between C2-C1-C1'-C2...
Figure 4: X-ray structures of BIFOP-nBu (5). Distances are given in Å. (BAA = biaryl angle between C2-C1-C1'-C...
Figure 5: X-ray structures of BIFOP(O)-H (8). Distances are given in Å. (BAA = biaryl angle between C2-C1-C1'...
Figure 6: X-ray structures of phosphite BIFOP-OPh (6). Distances are given in Å. (BAA = biaryl angle between C...
Figure 7: X-ray structures of phosphoramidite BIFOP-NEt2 (7). Distances are given in Å. (BAA = biaryl angle b...
Figure 8: X-ray structures of BIFOP(O)-Cl (9). Distances are given in Å. (BAA = biaryl angle between C2-C1-C1...
Scheme 4: Geometries of BIFOP-systems with respect to biaryl dihedral angles (C2-C1-C1’-C2’, BAA), fenchyl-ar...
Figure 9: Computed geometry (PM3) of plus-(P)-BIFOP-Cl with unnatural plus-(P)-biaryl conformation. Distances...
Scheme 5: Biphenyl-2,2'-bisfenchol based phosphanes (BIFOPs) as chiral ligands in enantioselective Cu-catalyz...
Scheme 6: Anharmonic B3LYP/6-31G*(C,H,N,O,F,Cl,Br) /SDD(Cu) CO-stretching frequencies to assess metal to liga...
