Direct Synthesis of Dibenzophospholes from Biaryls by Double C-P Bond Formation via Phosphenium Dication Equivalents.

We have developed a new strategy for the generation of phosphenium dication equivalents from readily available phosphinic acids and Tf2O. The in situ-generated dication equivalents can be readily coupled with simple (hetero)biaryls to form the corresponding dibenzophospholes directly. This protocol can also be applied to the concise synthesis of six- and seven-membered phosphacycles as well as the largely π-extended heteroacene derivatives, which are of great interest in the field of organic functional materials.