30932-37-7Relevant academic research and scientific papers
Transition metal-free coupling reactions of benzylic trimethylammonium salts with di(hetero)aryl disulfides and diselenides
Li, Fuhai,Wang, Dan,Chen, Hongyi,He, Ze,Zhou, Lihong,Zeng, Qingle
, p. 13029 - 13032 (2020/11/07)
A new protocol was developed to synthesize (enantioenriched) thioethers and selenoethers from (chiral) benzylic trimethylammonium salts and di(hetero)aryl disulfides or diselenides. These syntheses were promoted by the presence of weak base and did not require the use of any transition metal, and resulted in the target products with good to excellent yields (72-94%). Using quaternary ammonium salts synthesized from enantiomerically enriched amines led to highly enantiopure benzylic thioethers and selenoethers (94-99% ee) with configurations reversed from those of their enantioenriched quaternary ammonium salts. This journal is
Nanolayered cobalt-molybdenum sulphides (Co-Mo-S) catalyse borrowing hydrogen C-S bond formation reactions of thiols or H2S with alcohols
Corma, Avelino,Sorribes, Iván
, p. 3130 - 3142 (2019/03/13)
Nanolayered cobalt-molybdenum sulphide (Co-Mo-S) materials have been established as excellent catalysts for C-S bond construction. These catalysts allow for the preparation of a broad range of thioethers in good to excellent yields from structurally diverse thiols and readily available primary as well as secondary alcohols. Chemoselectivity in the presence of sensitive groups such as double bonds, nitriles, carboxylic esters and halogens has been demonstrated. It is also shown that the reaction takes place through a hydrogen-autotransfer (borrowing hydrogen) mechanism that involves Co-Mo-S-mediated dehydrogenation and hydrogenation reactions. A novel catalytic protocol based on the thioetherification of alcohols with hydrogen sulphide (H2S) to furnish symmetrical thioethers has also been developed using these earth-abundant metal-based sulphide catalysts.
Alkyl Sulfides as Promising Sulfur Sources: Metal-Free Synthesis of Aryl Alkyl Sulfides and Dialkyl Sulfides by Transalkylation of Simple Sulfides with Alkyl Halides
Liu, Ting,Qiu, Renhua,Zhu, Longzhi,Yin, Shuang-Feng,Au, Chak-Tong,Kambe, Nobuaki
supporting information, p. 3833 - 3837 (2018/12/05)
A site-selective metal-free dealkylative approach to synthesize aryl alkyl and symmetrical dialkyl sulfides has been developed. This procedure is convenient and has wide functional group tolerance giving rise to sulfides carrying various alkyl chains from simple alkyl sulfides and alkyl halides in good to excellent yields. This transalkylation proceeds by an ionic mechanism via sulfonium intermediates and it was proposed that dimethylacetamide (DMAC) may participate in part to promote the reaction.
Regioselective Synthesis of Selenide Ethers through a Decarboxylative Coupling Reaction
Cui, Fei-Hu,Chen, Jing,Su, Shi-Xia,Xu, Yan-Li,Wang, Heng-Shan,Pan, Ying-Ming
, p. 3950 - 3961 (2017/11/20)
An efficient and selective approach to the synthesis of selenide ethers containing one or two geminal C–Se bonds from readily available diselenides and phenylacetic acids was developed. Compounds containing one C–Se bond were prepared by employing air as the oxidant under metal-free conditions, whereas compounds having two geminal C–Se bonds were formed via the iron(III) chloride/oxygen/cesium carbonate (FeCl3/O2/Cs2CO3) system. Moreover, 1,2-diphenyldisulfane also could be smoothly converted into the corresponding sulfur ether product under the standard reaction conditions. (Figure presented.).
Neutral sulfur nucleophiles: Synthesis of thioethers and thioesters by substitution reactions of N-heterocyclic carbene boryl sulfides and thioamides
Pan, Xiangcheng,Curran, Dennis P.
supporting information, p. 2728 - 2731 (2014/06/09)
Newly discovered boryl sulfides and N-borylthioamides are shown to serve as neutral sources of sulfur nucleophiles in substitutions reactions. For example, heating of diMe-Imd-BH(SPh)2 with benzyl bromides, primary bromides, or acid chlorides provides the corresponding thioethers or thioesters in high yields. Likewise, N-phenyltetrazole thioethers/esters are made from a readily available N-borylthionotetrazole. The formation of the boryl sulfide and its onward nucleophilic substitution can be telescoped down to a one-pot reaction whose components are an NHC-borane (NHC-BH3), a disulfide, and an electrophile.
An efficient copper-catalyzed one-pot synthesis of diaryl thioethers by coupling of arylboronic acids with potassium ethyl xanthogenate under mild conditions
Wang, Liang,Zhou, Wei-You,Chen, Sheng-Chun,He, Ming-Yang,Chen, Qun
experimental part, p. 3041 - 3045 (2012/03/11)
A simple and environmentally benign one-pot synthesis of diaryl thioethers by coupling of arylboronic acids with potassium ethyl xanthogenate through a double arylation process has been developed. The aryl thiols were generated in situ, and the reactions proceeded smoothly to give the corresponding products in good to excellent yields under very mild conditions. Georg Thieme Verlag Stuttgart · New York.
Origin of the Stereoselectivity in (Ethoxycarbonyl)-, Cyano-, and Phenyl-Substituted (Arylsulfinyl)methyl Radicals
Renaud, Philippe,Bourquard, Thierry,Carrupt, Pierre-Alain,Gerster, Michèle
, p. 1048 - 1063 (2007/10/03)
An explanation for the very high diastereoselectivity observed for the reactions of carbonyl-substituted (arylsulfmyl)methyl radicals is presented, based on experimental results and semiempirical calculations. The influence of dipole-dipole interactions, allylic 1,3-strain(A1,3 strain), allylic 1,2-strain (A1,3 strain), and coulombic interactions is discussed based on stereoselectivities observed with (alkoxycarbonyl)-, cyano-, and aryl-substituted (arylsulfinyl)methyl radicals. In the second part, the effect of solvents and Lewis acids on the stereoselectivity of. reactions of (arylsulfmyl)- and (alkylsulfinyl)benzyl radicals has been examined.
Potentiation of the cytotoxicity of chloroethylnitrosourea by O6-arylmethylguanines
Kohda,Terashima,Koyama,Watanabe,Mineura
, p. 424 - 430 (2007/10/03)
It was reported recently that monomeric O6-benzylguanine (1) acts as an alternative substrate for a DNA repair enzyme, O6-alkylguanine-DNA alkyltransferase (AGT), and that therefore pretreatment of cells with 1 induces depletion of AGT resulting in an enhanced cytotoxic response to alkylating antitumor agents. In order to study the interaction of O6-benzylguanine derivatives with AGT and to obtain greater AGT depletion, me synthesized the following O6-arylmethylguanine derivatives and related compounds: O6-(4-, 3- and 2-fluorobenzyl)guanines (2, 3, 4), O6-(4-,3- and 2-trifluoromethylbenzyl)guanines (5, 6, 7), O6-(4-, 3- and 2-pyridylmethyl)guanines (8, 9, 10), O6-(2- and 1-naphthylmethyl)guanines (11, 12), O6-biphenylmethylguanine (13), S and Se analogues of O6-benzylguanine (14, 15) and O6-phenylguanine (16). Ten of these are new compounds. All these compounds were tested for their potentiation of N'-[(4-amino-2-methyl-5-pyrimidinyl)methyl] (ACNU) cytotoxicity using HeLa S3 and C6-1 cells. Compounds 2, 3, 5, 8, 9, 11 and 13 were active, as was 1. Compounds 7 and 12, with a substituent at the a position of the benzyl group, and compound 10, the a-nitrogen analogue of 1, were almost completely devoid of potentiating activity. These results suggest that the a-position of the O6-benzyl group plays an important role in the interaction of O6-benzylguanines with AGT. Of the other compounds, 4 and 6 exhibited very weak activity and 14, 15 and 16 were inactive. Possible reasons for these differences in activity are discussed in relation to the biomimetic dealkylation rates of O6-benzylguanine derivatives and the chemical characteristics of their substituents.
