Photoredox mediated nickel catalyzed C(sp<sup>3</sup>)–H thiocarbonylation of ethers
作者:Byungjoon Kang、Soon Hyeok Hong
DOI:10.1039/c7sc02516e
日期:——
photoredox/Ni dual catalysis. Thioester group of thiobenzoate is transferred to α-oxy carbon of various cyclic/acyclic ethers, opposite to the commonly expected chemical reactivity involving acyl group transfer via the weaker C(acyl)–S activation. Through mechanistic studies, we proposed that the reaction is initiated by photocatalytic reduction and fragmentation of the thioester into acyl radical and
通过可见光光氧化还原/ Ni双重催化可实现第一个直接的C(sp3)-H硫羰基直接反应。硫代苯甲酸酯的硫酸酯基团转移到各种环状/无环醚的α-氧碳上,这与通常期望的化学反应性相反,后者涉及通过较弱的C(酰基)-S活化来转移酰基。通过机理研究,我们提出该反应是通过光催化还原并将硫酯裂解成酰基和硫醇盐而引发的。镍配合物与硫醇盐结合,并诱导酰基的脱羰基化反应形成芳基,从而从醚的α-氧碳中夺取氢。生成的α-氧基C(sp3)中心自由基反弹至(RS)(CO)Ni络合物,该络合物经历CO迁移插入和还原消除反应,得到所需的硫酯产物。