Alkali Metal Hydridotriphenylborates [(L)M][HBPh₃] (M = Li, Na, K): Chemoselective Catalysts for Carbonyl and CO₂ Hydroboration

Abstract

Light alkali metal hydridotriphenylborates M[HBPh3] (M = Li, Na, K), characterized as tris{2-(dimethylamino)ethyl}amine (L) complexes [(L)M][HBPh3], act as efficient catalysts for the chemoselective hydroboration of a wide range of aldehydes and ketones using pinacolborane HBpin. The lithium derivative showed a remarkably high TOF of ≥17 s(-1). These compounds also catalyze the hydroborative reduction of CO2 to give formoxyborane HCO2Bpin without any over-reduction.