- Electroreductive Nickel-Catalyzed Thiolation: Efficient Cross-Electrophile Coupling for C?S Formation
-
Sulfur-containing molecules are of utmost topical importance towards the effective development of pharmaceuticals and functional materials. Herein, we present an efficient and mild electrochemical thiolation by cross-electrophile coupling of alkyl bromide
- Ang, Nate W. J.,Ackermann, Lutz
-
supporting information
p. 4883 - 4887
(2021/02/26)
-
- Novel and facile procedure for the synthesis of Ni(II) and Pd(II) PSCOP pincer complexes. Evaluation of their catalytic activity on C-S, C-Se and C-C cross coupling reactions
-
A new and facile procedure for the synthesis of non-symmetric phosphinito-thiophosphinito PSCOP pincer complexes based on Ni(II) and Pd(II) was developed. The synthesis of the complexes was carried out in a single step, starting from 3,3-dihydroxydiphenyldisulfide. The Ni(II) complexes were tested as catalysts in C-S and C-Se coupling reactions, being the tBu derivative 3-Ni the one exhibiting the best performance in both transformations. In this case, the sterics of the substrates was studied, showing that higher steric hindrance leads to lower yields. Analogously, the Pd(II) complexes were used as catalyst in Suzuki-Miyaura couplings of para-substituted bromobenzenes and phenyl boronic acid, being the analogous tBu derivative complex 3-Pd the best catalysts for this process, exhibiting tolerance to a wide range of functional groups.
- Valderrama-García, Bianca X.,Rufino-Felipe, Ernesto,Valdés, Hugo,Hernandez-Ortega, Simón,Aguilar-Castillo, Bethsy Adriana,Morales-Morales, David
-
-
- C[sbnd]S cross-coupling catalyzed by a series of easily accessible, well defined Ni(II) complexes of the type [(NHC)Ni(Cp)(Br)]
-
The synthesis, characterization and catalytic evaluation of a series of NHC-Ni(II) complexes 1-Ni (-Me), 2-Ni (-nBu) and 3-Ni (-Bn) bearing a phthalimide fragment and a cyclopentadienyl (Cp) ligand is reported. The complexes were evaluated in C
- Rodríguez-Cruz, Mario A.,Hernández-Ortega, Simón,Valdés, Hugo,Rufino-Felipe, Ernesto,Morales-Morales, David
-
p. 193 - 198
(2020/02/13)
-
- One-pot synthesis of α-phenylsulfinyl ketones by reaction of phenyl benzenethiosulfinate with enolate anions, and synthesis of sulfoxides and sulfides by its reaction with Grignard reagents
-
Phenyl benzenethiosulfinate reacts with enolate anions derived from ketones to give α-phenylsulfinyl ketones directly, together with minor amounts of α-phenylsulfanyl ketones. These are easily separated by forming the water-soluble sodium salts of the sulfinyl compounds. Grignard reagents also react with phenyl benzenethiosulfinate, to give mixtures of sulfoxides and sulfides.
- Fakhry, Jerome,Grayson, David H.
-
p. 556 - 563
(2017/12/28)
-
- CuI/Oxalic Diamide-Catalyzed Cross-Coupling of Thiols with Aryl Bromides and Chlorides
-
We report a general copper-catalyzed cross-coupling of thiols with aryl halides by using N-aryl-N′-alkyl oxalic diamide (L3) or N,N′-dialkyl oxalic diamide (L5) as the ligand. Both aryl and alkyl thiols can be coupled with unactivated aryl bromides and chlorides to give the desired products in good yields. Furthermore, this system features a broad substrate scope and good tolerance of functional groups. Importantly, the oxalic diamides are stable and can be prepared easily from commercially available and cheap starting materials.
- Chen, Chia-Wei,Chen, Yi-Ling,Reddy, Daggula Mallikarjuna,Du, Kai,Li, Chao-En,Shih, Bo-Hao,Xue, Yung-Jing,Lee, Chin-Fa
-
supporting information
p. 10087 - 10091
(2017/08/01)
-
- Reductive Lithiation in the Absence of Aromatic Electron Carriers. A Steric Effect Manifested on the Surface of Lithium Metal Leads to a Difference in Relative Reactivity Depending on Whether the Aromatic Electron Carrier Is Present or Absent
-
One of the most widely used methods of preparation of organolithium compounds is by the reductive lithiation of alkyl phenyl thioethers or, usually less conveniently, alkyl halides with either aromatic radical-anions of lithium or lithium metal in the presence of an aromatic electron-transfer catalyst. Here we present results showing that lithium dispersion can achieve reductive lithiation in the absence of the electron-transfer agent. This procedure is more efficient, and surprisingly, the order of reactivity of substrates is reversed depending on whether the electron-transfer agent is present or absent. For example, in the presence of a preformed radical-anion, tert-butyl phenyl sulfide cleaves significantly faster than methyl phenyl sulfide, whereas in the absence of the radical-anion, it is just the opposite. Density functional theory calculations reveal that the exothermicity of the cleavage of the C-S bond in alkyl phenyl thioethers on the lithium surface is dependent on the size of the alkyl group, the smaller the alkyl group the greater the exothermicity. The increased reactivity is attributed to the smaller steric repulsion between the alkyl group and the lithium surface. The methodology includes, but may not be limited to, the lithium dispersion reductive lithiation of phenyl thioethers, alkyl chlorides, acrolein diethyl acetal, and isochroman.
- Kennedy, Nicole,Lu, Gang,Liu, Peng,Cohen, Theodore
-
p. 8571 - 8582
(2015/09/15)
-
- Microwave-assisted C-C and C-S couplings catalysed by organometallic PD-SCS or coordination NI-SNS pincer complexes
-
A family of SCS and SNS pincer compounds of the type [PdCl{C6H3-2,6-(CH2SR)2}] {R = tBu (3a), sBu (3b), iBu (3c)} and [NiCl2{C5H3N-2,6-(CH2SR)2}] {R = tBu (4a), sBu (4b)} have been prepared. Among these, complexes 3b, 3c, 4a-4c are reported for the first time. Dimeric compounds such as [NiCl{C5H3N-2,6-(CH2SiBu)2}μ-Cl]2 (4c) were found in the solid state for the nickel complexes with lower steric hindrance exhibiting octahedral metal centers, whereas other nickel structures such as [NiCl2{C5H3N-2,6-(CH2StBu)2}(iPrOH)] (4d) could also expand their coordination number by coordinating to solvents. The single crystal X-ray diffraction results for 4a, 4c and 4d are presented. The catalytic activity of the six compounds was studied in C-C and C-S cross-coupling reactions under conventional heating and under microwave irradiation conditions. The palladium catalysts enabled good to excellent conversions in Suzuki-Miyaura couplings of p-substituted halobenzenes with phenylboronic acid. Comparable yields resulted from application of the nickel complexes in the thioetherification of iodobenzene with different disulfides. The fast increase in reaction temperature associated with microwave irradiation, in combination with the robust pincer catalysts, allowed for quantitative conversions in only minutes.
- Basauri-Molina, Manuel,Hernández-Ortega, Sim?n,Morales-Morales, David
-
p. 4619 - 4625
(2015/04/27)
-
- Lithium-titanium exchange of tertiary α-sulfonyl carbanions: Synthesis, structure, dynamics and reactivity of bis(1-sulfonylalkyl) titaniums
-
Lithium-titanium exchange of tertiary α-sulfonyl carbanions with ClTi(OiPr)3 and Cl2Ti(OiPr)2 in diethyl ether gave bis(1-sulfonylalkyl) titaniums and not the corresponding (1-sulfon-ylalkyl) titaniums. X-ray crystal structure analysis of di(iso-propoxy) bis[1-(phenylsulfonyl) cyclobutyl]titanium and di-(isopropoxy) bis[1-(phenylsulfonyl) isopropyl]titanium showed asymmetric distorted octahedral complexes, having hexaco-ordinate Ti atoms, two C-Ti bonds, four Ti-O bonds, and two four-membered Ti-O-S-Cα rings. According to 1H NMR spectroscopy bis(1-sulfonylcycloalkyl) titaniums are non-flux-ional at room temperature. This suggests that chiral bis(1-sulfonylalkyl) titaniums should be configurationally stable. The bis(1-sulfonylalkyl) titaniums are stable at room temperature towards β-H elimination. They selectively add to benzaldehyde in the presence of acetophenone but do not react with methyl iodide. The reaction of tertiary acyclic α-sulfonyl carbanions with ClTi(OiPr)3 in tetrahydrofuran (THF) gives different titanium derivatives with unspecified structures, which not only selectively react with benzaldehyde in the presence of acetophenone but are also alkylated by methyl iodide.
- Hess, Thomas,Raabe, Gerhard,Gais, Hans-Joachim
-
p. 7134 - 7147
(2015/03/04)
-
- Pinacol as a new green reducing agent: Molybdenum-catalyzed chemoselective reduction of sulfoxides and nitroaromatics
-
Pinacol is disclosed as a new chemoselective and environmentally benign reducing agent for sulfoxides and nitroaromatics assisted by readily available dichlorodioxomolybdenum(VI) complexes as catalysts. A wide range of substrates including those bearing challenging functional groups has been efficiently and selectively reduced with acetone and water being the only by-products of these reactions. Copyright
- Garcia, Nuria,Garcia-Garcia, Patricia,Fernandez-Rodriguez, Manuel A.,Rubio, Ruben,Pedrosa, Maria R.,Arnaiz, Francisco J.,Sanz, Roberto
-
supporting information; experimental part
p. 321 - 327
(2012/04/11)
-
- Experimental verification of diverging mechanisms in the binding of ether, thioether, and sulfone ligands to a dirhodium tetracarboxylate
-
Complexation of the oxygen atom in 2-butylphenylethers and sulfur in 2-butylphenylthioethers to a rhodium atom in dirhodium tetracarboxylate Rh (II)2[(R)-(+)-MTPA]4 is compared. Oxygen atoms complex via electrostatic attra
- Mattiza, Jens T.,Meyer, Vera J.,Duddeck, Helmut
-
experimental part
p. 192 - 197
(2010/07/05)
-
- Experimental and theoretical investigation of the enantiomerization of Lithium α-tert-butylsulfonyl carbanion salts and the determination of their structures in solution and in the crystal
-
Dynamic NMR (DNMR) spectroscopy of [R1C(R2)SO 2R3]Li (R1, R2 = alkyl, phenyl; R3 = Ph, tBu, adamantyl, CEt3) in [D8]THF has shown that the S-tBu, S-adamantyl, and S-CEt3 derivatives have a significantly higher enantiomerization barrier than their S-Ph analogues. C α-S bond rotation is most likely the rate-determining step of the enantiomerization of the salts bearing a bulky group at the S atom and two substituents at the Cα atom. Ab initio calculations on [Me(Ph)- SO 2tBu]- gave information about the two Cα-S rotational barriers, which are dominated by steric effects. Cryoscopy of [R1C(R 2)SO2tBu]Li in THF at -108°C revealed the existence of monomers and dimers. X-ray crystal structure analysis of the monomers and dimers of [R1C(R2)SO2tBu]Li·L n (R1 = Me, Et, tBuCH2, PhCH2, tBu; R2 = Ph, L = THF, 12-crown-4, PMDTA) and [R1C(R 2)SO2Ph]Li·2diglyme [R1 = R2 = Me, Et; R1-R2 = (CH2)5] showed them to be O-Li contact ion pairs (CIPs). The monomers and dimers have a Cα-S conformation in which the lone-pair orbital at the Cα atom bisects the O-S-O angle and a significantly shortened Cα-S bond. The Cα atom of [R1C(R2)SO2R 3]Li·Ln (R1 = Ph; R3 = Ph, tBu) is planar, whereas the Cα atom of [R1C(R 2)SO2R3]Li·Ln (R1 = R2 = alkyl) is strongly pyramidalized in the case of R3 = Ph and most likely planar for R3 = tBu. Ab initio calculations on [MeC- (Me)SO2R]- gave a pyramidalized Cα atom for R = Me and a nearly planar one for R = CF3 and tBu. The [R1C(R 2)SO2-tBu]Li salts were characterized by 1H, 13C, and 6Li NMR spectroscopy. 1H{ 1H} and 6Li{1H} NOE experiments are in accordance with the existence of O-Li CIPs. 1H and 13C NMR spectroscopy of [R1C(R2)SO2tBu]Li in [D 8]THF at low temperatures showed equilibrium mixtures of up to five different species being most likely monomeric and dimeric O-Li CIPs with different configurations. According to 7Li NMR spectroscopy, the addition of HMPA to [MeC(Ph)SO2tBu]Li in [D8]THF at low temperatures causes the formation of the separated ion pair [MeC(Ph)SO 2tBu]Li(HMPA)4.
- Scholz, Roland,Hellmann, Gunther,Rohs, Susanne,Raabe, Gerhard,Runsink, Jan,Oezdemir, Diana,Luche, Olaf,Hess, Thomas,Giesen, Alexander W.,Atodiresei, Juliana,Lindner, Hans J.,Gais, Hans-Joachim
-
supporting information; experimental part
p. 4559 - 4587
(2010/10/19)
-
- A general, efficient, and functional-group-tolerant catalyst system for the palladium-catalyzed thioetherification of aryl bromides and iodides
-
The cross-coupling reaction of aryl bromides and iodides with aliphatic and aromatic thiols catalyzed by palladium complexes of the bisphosphine ligand CyPF-tBu (1) is reported. Reactions occur in excellent yields, broad scope, high tolerance of functional groups, and with turnover numbers that exceed those of previous catalysts by 2 or 3 orders of magnitude. These couplings of bromo- and iodoarenes are more efficient than the corresponding reactions of chloroarenes and could be conducted with less catalyst loading and/or milder reaction conditions. Consequently, limitations regarding scope and functional group tolerance previously reported in the coupling of aryl chlorides are now overcome.
- Fernandez-Rodriguez, Manuel A.,Hartwig, John F.
-
experimental part
p. 1664 - 1672
(2009/07/17)
-
- CATALYSTS FOR ARYL SULFIDE SYNTHESIS AND METHOD OF PRODUCING ARYL SULFIDES
-
The present invention relates to the formation of aryl sulfides and aryl thiols from aryl halides and thiols, thiolates or thiolate equivalents. The present invention provides a catalyst for the coupling of aryl halides with alkyl or aryl thiols or a hydrogen sulfide equivalent to form aryl alkyl, aryl silyl or diaryl sulfides. The reaction encompasses bromoarenes and other similar compounds containing leaving groups as well as nitrile, ester, keto, free hydroxyl, free amino, free carboxylic acid and other common functionalities. The invention can be used to prepare pharmaceutical compounds, especially including their intermediates, agricultural agents and aryl sulfide polymers.
- -
-
Page/Page column 20; 33; 34
(2008/06/13)
-
- High yield thiolation of iodobenzene catalyzed by the phosphinite nickel PCP pincer complex: [NiCl{C6H3-2,6-(OPPh2)2}]
-
[NiCl{C6H3-2,6-(OPPh2)2}] efficiently catalyzes the thiolation of iodobenzene with a broad scope of disulfides in the presence of zinc, the coupled products are obtained in excellent and in many cases nearly quantitative yields.
- Gómez-Benítez, Valente,Baldovino-Pantaleón, Oscar,Herrera-álvarez, Cesar,Toscano, Rubén A.,Morales-Morales, David
-
p. 5059 - 5062
(2007/10/03)
-
- A general and long-lived catalyst for the palladium-catalyzed coupling of aryl halides with thiols
-
A general catalytic system for the coupling of aryl halides and sulfonates with thiols based on the use of the CyPF-t-Bu ligand (1) is reported. The reactions catalyzed by complexes of 1 occur in excellent yields with broad scope and exhibit extraordinary turnover numbers and high tolerance of functional groups. Turnover numbers usually exceed those of previous catalysts by 2 or 3 orders of magnitude. In addition, the reactions of aryl tosylates with alkane thiols to form aryl sulfides are reported for the first time. Finally, the synthesis of a diarylsulfide from two bromoarenes was accomplished using a hydrogen sulfide surrogate. Copyright
- Fernandez-Rodriguez, Manuel A.,Shen, Qilong,Hartwig, John F.
-
p. 2180 - 2181
(2007/10/03)
-
- Highly efficient and functional-group-tolerant catalysts for the palladium-catalyzed coupling of aryl chlorides with thiols
-
The cross-coupling reaction of aryl chlorides with aliphatic and aromatic thiols catalyzed by palladium complexes of the strongly binding bisphosphine CyPF-tBu ligand (1) is reported. Most of the reactions catalyzed by complexes of ligand 1 occur with turnover numbers that exceed those of previous catalysts by two orders of magnitude. The reactions occur with excellent yields, broad scope and high tolerance of functional groups. Coupling of aryl halides with thiols in the presence of low loadings of catalysts derived from other Josiphos type ligands, as well as ligands of other structural types, are also described.
- Fernandez-Rodriguez, Manuel A.,Shen, Qilong,Hartwig, John F.
-
p. 7782 - 7796
(2007/10/03)
-
- Trimethylchlorosilane (TMCS) catalyzed efficient reduction of sulfoxides to thioethers using 3-mercaptopropionic acid under mild reaction conditions
-
A variety of alkyl and aryl sulfoxides were successfully deoxygenated using 3-mercaptopropionic acid as reducing agent and a catalytic amount of trimethylchlorosilane (10-20 mol%) in CH3CN at ambient temperature.
- Karimi, Babak,Zareyee, Daryoush
-
-
- Rapid, efficient and chemoselective deoxygenation of sulfoxides to thioethers using NaBH4/I2
-
Sodium borohydride in the presence of iodine in anhydrous THF converts a range of structurally different sulfoxides to their thioethers in excellent yields. It has been found that chemoselective deoxygenation of sulfoxides can be achieved in the presence of other reducible functional groups such as esters, nitriles and double bonds.
- Karimi, Babak,Zareyee, Daryoush
-
p. 335 - 336
(2007/10/03)
-
- N-bromosuccinimide and iodine catalyzed highly efficient deoxygenation of sulfoxides to thioethers using 3-mercaptopropionic acid under mild reaction conditions
-
A variety of alkyl and aryl sulfoxides have been successfdlly deoxygenated using 3-mercaptopropionic acid as a reducing agent and a catalytic amount of either NBS or I2 (5-10 mol%) in MeCN at ambient temperature. Under the described reaction condition, acid sensitive substrates such as acetals remained intact after several hours.
- Karimi, Babak,Zareyee, Daryoush
-
p. 1875 - 1877
(2007/10/03)
-
- Reactions of 5-(alkyl)thianthrenium and other sulfonium salts with nucleophiles
-
A series of 5-(alkyl)thianthrenium triflates (3a-d, g-i) with alkyl (R) groups Me (a), Et (b), isoPr (c), 2-Bu (d), cyclopentyl (g), cyclohexyl (h) and cycloheptyl (i) were prepared by alkylation of thianthrene (Th) with alkyl formate and trifluoromethanesulfonic (triflic) acid. Benzylation (3f) was achieved with benzyl bromide and silver triflate. 5-(Neopentyl)thianthrenium perchlorate (3e) was prepared by reaction of thianthrene cation radical perchlorate with dineopentyl mercury. Methyl- (4a) and cyclohexyldiphenylsulfonium triflate (4b) were made by alkylation of diphenyl sulfide. Benzyldimethyl- (5a), dibenzylmethyl- (5b) and benzylmethylphenylsulfonium perchlorate (5c) were prepared in standard ways. Reactions of these sulfonium salts with iodide ion and thiophenoxide ion were studied for comparison with our earlier reported reactions of comparable 5-(alkoxy)thianthrenium and methoxydiphenylsulfonium salts. It is deduced that reactions of 3-5 with nucleophiles (Nu-) I- and PhS- follow traditional SN2 and E2C paths. Thus, the salts 3a-c, e and f gave virtually quantitative yields of RNu and Th, while small amounts of butene(s) were obtained from 3d. The cycloalkyl salts 3g-i gave amounts of cycloalkylNu and cycloalkene typical of competition of SN2 and E2C routes in the classical reactions of cycloalkyl halides and tosylates with I- and PhS- ions. Whereas 4a gave only SN2 products, 4b gave SN2 and E2C products typical of SN2/E2C competition. Among the salts 5a-c displacement of the benzyl group was dominant (5a) or exclusive (5b, c), thus exhibiting the preferential displacement of a benzyl group that has been fully documented in earlier studies of SN2 reactions. Qualitative comparison showed that 3a (methyl) reacted much faster than 3e (neopentyl) with PhS-. Unlike alkoxysulfonium salts, the salts 3-5 do not appear to undergo reactions at the sulfonium sulfur atom. Copyright
- Liu, Bo,Shine, Henry J.
-
-
- Alkyl- and Arylthiodediazoniations of Dry Arenediazonium o-Benzenedisulfonimides. Efficient and Safe Modifications of the Stadler and Ziegler Reactions to Prepare Alkyl Aryl and Diaryl Sulfides
-
The reaction between dry arenediazonium o-benzenedisulfonimides 1 and sodium thiolates in anhydrous methanol represents an efficient and safe procedure, of general validity, for the preparation of unfunctionalized or variously functionalized alkyl aryl and diaryl sulfides. As a rule, the reaction temperature was maintained at 0-5°C for the alkylthiodediazoniations and at room temperature (20-25°C) for the arylthiodediazoniations. The sulfide yields are generally high; of the 63 considered examples, 43 gave yields greater than 80% and 13 were between 70% and 80%. Lower yields were obtained only when sterically hindered diazonium salts or thiols were used. A good amount of the o-benzenedisulfonimide (8) was always recovered from the reactions and could be reused to prepare salts 1. The copious experimental data collected in homogeneous conditions have offered several starting points for the study of the mechanism of these reactions.
- Barbero, Margherita,Degani, Iacopo,Diulgheroff, Nicola,Dughera, Stefano,Fochi, Rita,Migliaccio, Mara
-
p. 5600 - 5608
(2007/10/03)
-
- Metalation reactions. XXIV. Metalation of (vinylthio)benzene
-
The addition of organolithium compounds to (vinylthio)benzene (1) and then an electrophilic quenching followed by a further metalation/electrophilic quenching is a general method to prepare in one pot (alkylthio)benzenes ortho, alpha-substituted with equal or different groups. The direct dimetalation of 1 affords the ortho, alpha-dilithiated species 15 besides other by-products. Starting from 15 it is possible to obtain in one step ortho, alpha-substituted (vinylthio)benzenes and heterocyclic compounds.
- Cabiddu, Maria Grazia,Cabiddu, Salvatore,Cadoni, Enzo,Cannas, Rita,Fattuoni, Claudia,Melis, Stefana
-
p. 14095 - 14104
(2007/10/03)
-
- The palladium-catalyzed cross-coupling reaction of 9-organothio-9-borabicyclo[3.3.1]nonanes with organic electrophiles: Synthesis of unsymmetrical sulfides
-
The synthesis of unsymmetrical sulfides was carried out in high yields by the palladium-catalyzed cross-coupling reaction of 9-organothio-9-borabicyclo[3.3.1]nonane (9-RS-9-BBN) with organic electrophiles, such as iodoarenes, 1-iodo-1-alkenes, allyl carbonate and propargyl carbonate. Iodoarenes and 1-iodo-1-atkenes were smoothly converted into the corresponding sulfides at 50 °C in the presence of PdC12(dppf) (3 mol%) and K3PO4 (3 equiv.) in DMF. In contrast, the cross-coupling reaction of 9-RS-9-BBN with allyl or propargyl carbonates occurred in DMF without the assistance of a base. Both reactions catalyzed by Pd(dba)2-dppf regioselectively produced allyl and allenyl sulfides in excellent yields. The scope and limitations of the reactions, as well as the effects of varying the reaction conditions, are discussed.
- Ishiyama, Tatsuo,Mori, Masashi,Suzuki, Akira,Miyaura, Norio
-
p. 225 - 231
(2007/10/03)
-
- Metallation Reactions. XVIII. Regioselective metallation of (alkylthio)benzenes by superbases
-
(Alkylthio)benzenes were monometallated at the alpha position by a stoichiometric mixture of butyllithium and potassium t-butoxide and bimetallated at both the alpha and the ortho positions by two equivalents of the same reagent.
- Cabiddu, S.,Fattuoni, C.,Floris, C.,Gelli, G.,Melis, S.
-
p. 197 - 202
(2007/10/02)
-
- Lewis Acid Induced Nucleophilic Substitution Reaction of β-Nitro Sulfides
-
The nitro group of β-nitro sulfides is readily substituted by an allyl or a cyano group or hydrogen on treatment with allyltrimethylsilane, cyanotrimethylsilane, or triethylsilane in the presence of an appropriate Lewis acid.The intramolecular Friedel-Cra
- Kamimura, Akio,Sasatani, Hiroyuki,Hashimoto, Toshihiro,Ono, Noboru
-
p. 4998 - 5003
(2007/10/02)
-
- IONIC DENITROHYDROGENATION OF α-NITRO OR β-NITRO SULFIDES WITH TRIETHYLSILANE
-
The nitro groups of α-nitro or β-nitro sulfides are replaced by hydrogen on treatment with triethylsilane in the presence of Lewis acid.
- Ono, Noboru,Hashimoto, Toshihiro,Jun, Tuo Xiao,Kaji, Aritsune
-
p. 2277 - 2280
(2007/10/02)
-
- New Reagents, XXXVII - (α-Lithioalkyl)diphenylarsane Oxides: Synthesis and Application for the Indirect Nucleophilic Haloalkylation
-
Due to ready accessibility and high nucleophilicity (α-lithioalkyl)diphenylarsane oxides (2) are favorable reagents for the synthesis of many organoarsenic compounds.In organic synthesis they are recommendable as reagents for indirect nucleophilic haloalkylation reactions (Hal = Cl, Br, I).
- Kauffmann, Thomas,Joussen, Rolf,Woltermann, Annegret
-
p. 2135 - 2142
(2007/10/02)
-
- 17O NMR Spectra of Tertiary Alcohols, Ethers, Sulfoxides and Sulfones in the Cyclohexyl and 5-Substituted 1,3-Dioxanyl Series and Related Compounds
-
17O NMR spectra of fifteen cyclohexane-derived tertiary alcohols and related ethers and acetals, six 1,3-dioxane-derived orthoesters, four cyclohexane- and 1,3-dioxane-derived sulfones and the four corresponding sulfoxides, three acyclic sulfones, six alc
- Manoharan, Muthiah,Eliel, Ernest L.
-
p. 225 - 231
(2007/10/02)
-
- HYDRIDE ABSTRACTION AND REGIOSELECTIVE INSERTION REACTION AT β C-H BOND OF ALKYLLITHIUM BY ETHYL(PHENYLTHIO)METHYLENE CARBENOID
-
Study on the reaction of alkyllithium with 1-chloropropyl phenyl sulfide showed two novel reactions, the regioselective insertion and the hydride abstraction, at the β C-H bond of alkyllithium by ethyl(phenylthio)methylene carbenoid.
- Harada, Toshiro,Maeda, Hisatomo,Oku, Akira
-
p. 6489 - 6492
(2007/10/02)
-
- Deoxygenation and Desulphuration Reactions of Lithium: Part V - Reaction of Sulphoxides with Lithium
-
Dialkyl and aralkyl sulphoxides are reduced to the corresponding sulphides in good yields by lithium in dimethoxyethane; however, the reaction of benzyl sulphoxides with lithium is more complex.
- Rajanikanth, B.,Ravindranath, B.
-
p. 296 - 297
(2007/10/02)
-
- TITANIUM TETRACHLORIDE PROMOTED REDUCTION OF ALKENYL SULFIDES USING TRIETHYLSILANE AS A REDCING AGENT
-
Alkenyl sulfides were reduced to the corresponding alkyl sulfides with triethylsilane in the presence of titanium tetrachloride in good yields.The reduction proceeds via -phenylthio-alkyltitanium intermediate.
- Takeda, Takeshi,Tsuchida, Toshio,Fujiwara, Tooru
-
p. 1219 - 1220
(2007/10/02)
-
- Carbene Anion Formation from a Dithioacetal Anion Bearing an Allylic Oxyanion Substituent at the 2 Position. Divergent Behavior of the Dianion in Ether and THF
-
The recently proposed principle that diphenyl dithioacetal anions decompose to carbenes when present in a molecule possessing a second anionic site has been applied to a dithioacetal anion possessing an oxyanion at the 2 position.When the alcohol 3, arising from 1,2-addition of tris(phenylthio)methyllithium to crotonaldehyde, is treated with 2 molar equiv of sec-butyllithium at -50 deg C, the dianion 4 is produced by deprotonation and sulfur-lithium exchange.When this dianion is warmed to 0 deg C in THF, the carbene anion that is generated undergoes the expected 1,2-H transfer to yield trans-1-(phenylthio)pent-3-en-2-one (5).The main product (7) of decomposition of the same dianion in ether solution arises by loss of the Li2O and 1,4-addition of sec-butyllithium to the resulting conjugated ketene dithioacetal (10).
- Cohen, Theodore,Yu, Lin-Chen
-
p. 605 - 608
(2007/10/02)
-
- One-Electron Chemical Reductions of Phenylalkylsulfonium Salts
-
Twenty-two arylalkylsulfonium salts have been reduced with potassium in graphite in tetrahydrofuran and the sulfide products identified.Two trialkylsulfonium salts did not reduce under these conditions.Comparison of the sulfides from a series of monophenylalkylsulfonium salts reveals a leaving-group propensity of benzyl > secondary > primary > methyl > phenyl in a ratio of 28:(6.0 +/- 0.3):1.0:(0.53 +/- 0.09): 0.05.The cleavage ratio is shown to be independent of the electron source and the homogeneity of heterogeneity of the reaction in two cases.Multiplicative transitivity of the above ratios is not observed, although the same qualitative order is found for other comparisons.These results are interpreted in terms of the initial formation of a ?-ligand radical anion sulfonium cation, which undergoes cleavage to a carbon radical and a sulfide.This appears to be the first evidence for this type of structure in a sulfur system.Leaving-group propensities different from the above order are observed in reductions of diphenylsulfonium and benzo-fused sulfonium salts, and rationales are offered.The intermediates in these reactions appear to be different from those involved in radical additions to, or displacements on, sulfur.
- Beak, Peter,Sullivan, Thomas A.
-
p. 4450 - 4457
(2007/10/02)
-
- Thermal and Photochemical Reactions of Organocobaloximes with Diphenyl Disulphide and Diphenyl Diselenide
-
Alkyl- and benzyl-bis(dimethylglyoximato)pyridinecobalt(III) complexes react with diphenyl disulphide or diphenyl diselenide, thermally and photochemically, to give good yields of alkyl or benzyl phenyl sulphides or selenides.Chiral alkylcobalt(III) complexes react to give racemic alkyl phenyl sulphides or selenides.Allyl- and propadienyl-bis(dimethylglyoxymato)pyridinecobalt(III) complexes react similarly to give the thermodynamically more stable allyl, propadienyl, or propynyl phenyl sulphides or selenides.These reactions are interpreted in terms of free radical processes in which organic radicals formed as a result of thermal, photochemical, or chemically induced homolysis of the organocobalt complex, attack the diphenyl dichalcogenide to give the product organo phenyl chalcogenide.No evidence could be obtained for the direct attack of phenylthiyl or phenylselenyl radicals on the organic ligand of the organocobalt complexes, though this process cannot be excluded in the case of allylcobalt complexes.
- Deniau, Jean,Duong, Kiem N. V.,Gaudemer, Alain,Bougeard, Peter,Johnson, Michael D.
-
p. 393 - 398
(2007/10/02)
-
- PHASE TRANSFER CATALYSIS USING CHIRAL CATALYSTS. V. ASYMMETRIC NUCLEOPHILIC SUBSTITUTIONS WITH C, O, N AND S-ANIONS
-
Several asymmetric nucleophilic substitutions with C, N, O and S-anions have been performed under PTC conditions using chiral quaternary ammonium salts as PT catalysts.
- Julia, S.,Ginebreda, A.,Guixer, J.,Tomas, A.
-
p. 3709 - 3712
(2007/10/02)
-