Additive-free, N-chlorosuccinimide-promoted electrophilic phosphorothiolation/cyclization of alkynes with P(O)SH compounds to access heterocyclic phosphorothiolated molecules

Abstract

A simple and practical strategy for the synthesis of phosphorothiolated heterocyclic compounds from easily prepared alkynes and P(O)SH compounds has been developed. With the assistance of NCS, the nucleophilic P(O)SH could be converted to the electrophilic phosphoranesulfenyl chloride in situ, which then induced the regioselective phosphorothiolation/cyclization under metal- and additive-free conditions. This protocol allows the rapid construction of diverse phosphorothiolated benzofurans, benzothiophenes, and isocoumarins with good yields, which opens up an avenue for the introduction of the phosphorothioate group into biologically interesting heterocyclic scaffolds.