comparable with other M-(-H)2-BBN complexes. The use of 1 equiv. of (H-BBN)2 resulted in the full conversion of 10 into 3a and 11. The formation of 11 was confirmed by single crystal X-ray diffraction studies (inset Fig. ). The structure of 11 contains a Zn---B distance of 2.179 Å consistent with a borohydride unit bound to zinc via two bridging hydrogens, with 11 having comparable metrics to NacNacZn-(-H)2-BH2. Complex 11 also can be synthesized from NacNacZnH 1 by addition of 0.5 equivalent of (H-BBN)2. Note, while the boron center in 11 is structurally similar to the active boron electrophile in Wang's borocation- mediated catalytic C-H borylation, complex 11 is neutral and thus is a weak electrophile at boron which is not active in C-H borylation (Table , entry 5). ] and 1 react rapidly at room temperature). This may explain the poor outcomes using [(Et3N)H][B(C6F5)4] in the catalytic borylation compared to that using