Abstract The reaction of sodium or caesium dithiocarboxylates with diphenylthiophosphinic and diphenylselenophosphinic chlorides gives purple thioacyl diphenylthiophosphinoyl 5 and dark green thioacyl diphenylselenophosphinoyl sulfides 6, which are useful thioacylating reagents under mild reaction conditions. Thioacyl diphenylphosphino sulfides 22, which can be obtained by the similar method using diphenylphosphinous chlorides, ...