Synthesis of PI, PIII, and PV Compounds Supported by Bis(benzimidazole)Benzene.

A series of phosphorus compounds bearing the 4-tert-butyl-2,6-bis(benzimidazol-2-yl)benzene ligand (BZIMB) were prepared and fully characterized using spectroscopic methods, including X-ray crystallography. Reaction of the PIII compounds with electrophilic reagents led to PV compounds. Reaction with reducing reagents led to PI phosphinidenes. The phosphinidenes react with electrophilic reagents to generate new PIII compounds. In contrast to topologically related compounds featuring labile P─N bonds, the robust P─C bond between the phosphorus center and the ligand prevents dissociation of the phosphorus atom during oxidation and reduction, showing the potential for small molecule activation and opening the door for future catalytic studies.