Photoredox/copper-catalyzed coupling of terminal alkynes with P(O)SH compounds leading to alkynyl phosphorothioates

Abstract

The direct construction of a C(sp)–S–P(O) moiety from unactivated terminal alkynes remains highly challenging. Alkynyl phosphorothioates are obtained by coupling terminal alkynes and P(O)SH. Using commercially available and inexpensive Ru(bpy)₃Cl₂ and copper as a catalyst, this cross dehydrogenative coupling reaction is first performed under photoirradiation. Direct use of stable P(O)SH and terminal alkynes without the need to prepare unstable S–X and P–X derivatives represents a prominent advantage of this method. More attractively, this operationally simple reaction avoids the use of odorous thiols and poisonous alkynyl bromides.