TBPB-promoted metal-free synthesis of thiophosphinate/phosphonothioate by direct P-S bond coupling

An efficient method for the direct coupling of thiol/thiophenol with H-phosphine oxides or H-phosphinate esters is reported. Without using any metallic catalyst, the direct sulfur-phosphorus bond coupling reaction was promoted using tert-butyl peroxybenzoate in the presence of KI at room temperature. Consequently, thiophosphinate/phosphonothioate was produced in moderate to excellent yields.