A Bench-Stable Platform [TBA][PS2Cl2] Enables Sequential Assembly of Unsymmetric Tri- and Tetrathiophosphates

Abstract

Unsymmetric tri- and tetrathiophosphates with distinct S-substituents are synthetically challenging. Here, we report a bench-stable P(V)–S platform, tetrabutylammonium dichlorodithiophosphorane ([TBA][PS2Cl2]), prepared by mild redox-neutral halogenation of commercial P4S10 at room temperature. This modular platform enables the selective phosphorothiolation of various thiols, thiophenols, amino acids, short peptides, glycosides, and natural products to construct a broad range of unsymmetric tri- and tetrathiophosphates, which are difficult to synthesize by traditional multistep routes. The products are versatile intermediates for C(sp3)–S, C(sp2)–S, and N–S bond formations, offering a practical toolkit for complex thiophosphate architectures.