Enabled by its enhanced electrophilicity and attenuated nucleophilicity, an N,N'-diamidocarbene (DAC) was found to promote the B-H bond activation of various BH3 complexes and the B-B bond of bis(pinacolato)diboron, constituting the first such examples for an isolable carbene. The resultant DAC-BH3 adducts datively coordinated to Lewis bases (i.e., dimethyl sulfide, trimethylamine, or pyridine) and facilitated the hydroboration of various olefins under mild conditions and in the absence of exogenous initiators.