Synthesis of (Deoxy)difluoromethylated Phosphines by Reaction of RP(O)H with TMSCF and Their Application in Cu(I) Clusters in Sonogashira Coupling.

RPCFH ligands and their RP(O)CFH precursors were synthesized from RP(O)H with TMSCF by simply modulating the HO concentration via deoxydifluoromethylation and difluoromethylation. The air sensitive RPCFH phosphines can be stabilized in Cu(I) clusters as ligands. Within these Cu(I) clusters, the Sonogashira cross-coupling reaction can proceed fast and efficiently using terminal alkynes and aryl iodides within 15 min at room temperature under air to give a variety of diaryl(alkyl)acetylenes in good yields (49 examples, yields of ≤99%). Six of the internal alkynes present in drug precursors can be obtained using this protocol in good yields. The mechanism is proposed on the basis of control experiments.