本报告描述了镍催化脱羰反应的发展,用于从相应的硫酯合成氟烷基硫醚 (R F SR)。容易获得、便宜且稳定的氟代烷基羧酸 (R F CO 2 H) 作为该转化中的氟代烷基 (R F ) 源。化学计量有机金属研究表明,形成R F -S 键的还原消除是催化循环中的一个具有挑战性的步骤。这导致二苯基膦二茂铁被鉴定为该转化的最佳配体。最终,该方法应用于构建多种氟代烷基硫醚 (R F SR),其中 R = 芳基和烷基。
S-, N-, and Se-Difluoromethylation Using Sodium Chlorodifluoroacetate
作者:Vaibhav P. Mehta、Michael F. Greaney
DOI:10.1021/ol402370f
日期:2013.10.4
thiols is reported using chlorodifluoroacetate as the difluoromethylating agent. This cheap reagent undergoes smooth decarboxylation at 95 °C to afforddifluorocarbene, which can be trapped with a variety of aromatic and heteroaromatic thiols. The reaction is also effective for the difluoromethylation of heterocyclic nitrogen compounds and phenylselenol.
Visible light-promoted difluoromethylthiolation of aryldiazonium salts
作者:Wengui Wang、Shuxiang Zhang、Huaiqing Zhao、Shoufeng Wang
DOI:10.1039/c8ob02431f
日期:——
Difluoromethylthiolation of aryldiazoniumsalts under photocatalytic conditions with a shelf-stable, easily prepared and inexpensive reagent, PhSO2SCF2H was described. A variety of difluoromethylthioethers were obtained utilizing aryldiazoniumsalts containing different functional groups. Aryldiazoniumsalts with a heteroarene moiety were tolerated. Fluorescence quenching experiments indicated that
Radical Difluoromethylation of Thiols with (Difluoromethyl)triphenylphosphonium Bromide
作者:Niklas B. Heine、Armido Studer
DOI:10.1021/acs.orglett.7b02109
日期:2017.8.4
A method for facile difluoromethylation of various thiols using (difluoromethyl)triphenylphosphonium bromide under mild reaction conditions is presented. The transformation proceeds in the absence of any transition metal using a bench-stable and readily accessible phosphonium salt. Deuterium labeling experiments and cyclic voltammetry measurements reveal that the difluoromethylation occurs via a S(RN)1-type mechanism. Substrate scope is broad, and various functional groups are tolerated (OH, NH2, amide, ester).
Use of Fluoroform as a Source of Difluorocarbene in the Synthesis of Difluoromethoxy- and Difluorothiomethoxyarenes
作者:Charles S. Thomoson、William R. Dolbier
DOI:10.1021/jo401392f
日期:2013.9.6
Fluoroform, CHF3, a non-ozone-depleting, nontoxic, and inexpensive gas can be used as a difluorocarbene source in a process for the conversion of phenols and thiophenols to their difluoromethoxy and difluorothiomethoxy derivatives. The reactions are carried out at moderate temperatures and atmospheric pressure, using potassium hydroxide as base in a two-phase (water/dioxane or water/acetonitrile) process to provide moderate to good yields of the respective products.