Versatile P-N and P-O bond-forming reactions by an umpolung approach using air- and moisture-stable hydroxymethylphosphine sulfides were developed. Phosphine sulfides containing multiple hydroxymethyl groups could undergo sequential transformations combining P-N and P-O as well as P-C bond formations, providing a novel protocol for the synthesis of a variety of organophosphorus(V) compounds with P-N and P-O bonds.