Phosphidoboratabenzene–rhodium(i) complexes as precatalysts for the hydrogenation of alkenes at room temperature and atmospheric pressure

Abstract

The di-tert-butylphosphido-boratabenzene ligand (DTBB) reacts with [(C₂H₄)₂RhCl]₂ yielding the dimeric species [(C₂H₄)Rh(DTBB)]₂ (1). This species was fully characterized by multinuclear NMR and X-ray crystallography. Complex 1 readily dissociates ethylene in solution and upon exposure to 1 atm of H₂ is capable of carrying out the hydrogenation of ethylene. The characterization of two Rh–H species by multinuclear NMR spectroscopy is provided. The reactivity of 1 towards the catalytic hydrogenation of alkenes and alkynes at room temperature and 1 atm of H₂ is reported and compared to the activity of Wilkinson's catalyst under the same reaction conditions.