Late-Stage Diversification of Biarylphosphines through Rhodium(I)-Catalyzed C-H Bond Alkenylation with Internal Alkynes.

We report herein P(III)-directed C-H bond alkenylation of (dialkyl)- and (diaryl)biarylphosphines using internal alkynes. Chloride-free [Rh(OAc)(COD)]2 acts as a better catalyst than commercially available [RhCl(COD)]2. Conditions were developed to control the mono- and difunctionalization depending on the alkyne stoichiometry. One of these novel bisalkenylated (dialkyl)biarylphosphines was employed for the preparation of a palladium(II) complex, and some of these functionalized ligands outperformed their corresponding unfunctionalized phosphines in Pd-catalyzed amidation with sterically hindered aryl chlorides.