Electrochemical Direct Thiolation of Lactams with Mercaptans: An Efficient Access to N-Acylsulfenamides

An efficient and eco-friendly electrochemical methodology for the oxidative cross coupling hydrogen evolution (CCHE) reactions of lactams with thiols is presented. Various electron deficient N-acylsulfenamides are smoothly produced in modest to excellent yields without using any external oxidant. Elementary mechanistic insight supports a possible free radical process and hydrogen is the only side product. This approach provides a safe, convenient, and economical preparation of synthetically important N-thiophthalimides on a gram scale.

Automated summary

An efficient and eco-friendly electrochemical methodology was developed for the oxidative cross coupling hydrogen evolution reactions of lactams with thiols, yielding electron deficient N-acylsulfenamides in modest to excellent yields without the need for external oxidants. The mechanism involves a possible free radical process, with hydrogen being the only byproduct. This approach enables the safe, convenient, and economical gram scale preparation of synthetically important N-thiophthalimides.