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

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.