Radical–Radical Cross-Coupling for C–S Bond Formation
作者:Zhiliang Huang、Dongchao Zhang、Xiaotian Qi、Zhiyuan Yan、Mengfan Wang、Haiming Yan、Aiwen Lei
DOI:10.1021/acs.orglett.6b00764
日期:2016.5.20
A new method was demonstrated to overcome the selectivity issue of radical–radical cross-coupling toward the synthesis of asymmetric diaryl thioethers. The preliminary mechanism was revealed by radical-trapping experiments, DFT calculations, and kinetics, etc., indicating that the C–S bond formed through cross-coupling of a thiyl radical and an aryl radical cation. Moreover, the formation of an aryl
A metal- and oxidant-free electrochemical synthesis of aryl sulfides was developed through a C–H sulfidation reaction of arenes and disulfides. Compared with traditional organic synthesis methods, this direct electrochemical approach efficiently generates aryl sulfides under catalyst- and oxidant-free conditions with the superiorities of wide substrate compatibility, mild reaction condition and waster
C–H sulfidation or selenation of arenes by a Pd(II)/Cu(II) catalytic system: Preparation of unsymmetrical sulfides or selenides by C–H functionalization has been disclosed. This protocol could be applied a various of arenes. In the case of using an indolizine and pentafluorobenzene, bis‐sulfidated product were obtained.
A CuI-catalyzed direct access to sulfides from disulfides via C-H bond cleavage of di- or trimethoxybenzene is described. The procedure utilizes O-2 as a clean and cheap oxidant. Direct selenation of the C-H bond also took place under this procedure. Furthermore, the system enables the use of two RS in (RS)(2). Thus, it represents an atom-economical procedure for the synthesis of sulfides and selenides.
Iron-Catalyzed Direct C-H Thiolation of Trimethoxybenzene with Disulfides
An iron-catalyzed thiolation access to sulfides from disulfides via arene C-H bond cleavage of trimethoxybenzene is described. The procedure tolerates methoxyl, fluoro, chloro, bromo, nitro, and heterocyclic groups, using air as the clean and terminal oxidant.