Terminal Phosphanido Rhodium Complexes Mediating Catalytic P—P and P—C Bond Formation

Complexes with terminal phosphanido (M—PR₂) functionalities are believed to be crucial intermediates in new catalytic processes involving the formation of P—P and P—C bonds. We showcase here the isolation and characterization of mononuclear phosphanide rhodium complexes ([RhTp(H)(PR₂)L]) that result from the oxidative addition of secondary phosphanes, a reaction that was also explored computationally. These compounds are active catalysts for the dehydrocoupling of PHPh₂ to Ph₂P—PPh₂. The hydrophosphination of dimethyl maleate and the unactivated olefin ethylene is also reported. Reliable evidence for the prominent role of mononuclear phosphanido rhodium species in these reactions is also provided.