Electrochemical phosphorothiolation and 1,4-S → C phospho-Fries rearrangement: controlled access to phosphorothiolated and mercapto-phosphono substituted indolizines†

An unprecedented electrochemically regioselective C–H phosphorothiolation and S- to C-[1,4] phosphoryl migration involving indolizines, elemental sulfur, and H-phosphonates in an undivided cell has been developed. This strategy utilizes elemental sulfur as an odorless sulfur source, providing a new avenue for the formation of C(sp²)–S–P bonds under sustainable conditions. Various phosphorothiolated and mercapto-phosphono substituted indolizines were obtained via controllable electrochemical phosphorothiolation and a 1,4-S → C phospho-Fries rearrangement. Additionally, this is the first example of successive electrochemical phosphorothiolation and a 1,4-S → C phospho-Fries rearrangement.