Simple and efficient synthesis of 2,2-disubstituted-1,1-difluorophosphonates and phosphonothioates.

Generation of dialkyl phosphonyl and thiophosphonyl radicals in the presence of 1,1-difluoroolefins furnishes regioadducts 1, thereby providing the first general synthesis of 2,2-disubstituted-1, 1-difluorophosphonates and -phosphonothioates. Phosphinyl radicals and radicals derived from diarylphosphine oxide are shown to behave in an analogous manner. Addition of the same radicals onto a monosubstituted 1,1-difluoroolefin gives mainly the reverse regioadduct, thus demonstrating the complementarity of the new preparation with the synthetic methods available from the literature.