A Highly Active Suzuki Catalyst for the Synthesis of Sterically Hindered Biaryls:  Novel Ligand Coordination

A catalyst system for the preparation of biaryls containing four ortho substituents via Suzuki coupling is described. The combination of a catalytic quantity of Pd2(dba)3 with either an electron-rich biarylphosphine or DPEPhos is effective using a wide range of substrates. The X-ray crystal structure of (dba)Pd(2-(9-phenanthryl)phenyl-dicyclohexylphosphine), in which the Pd is coordinated to the 9,10-double bond of the phenanthryl group, is also reported.