Mechanistic insight and reaction development. We began our studies with the reaction of t BuOK with β-silyl benzylic boronates I′ (prepared via silylboration of styrene ) (Fig. ). Our density functional theory (DFT) calculations with M06-2X functional show that the ate complex II′, resulting from the complexation of I′ with t BuOK is thermodynamically stable (ΔG = -16.4 kcal/mol). Its heterolysis into the β-sily benzylic anion and t BuOBpin complex III′ is kinetically feasible (ΔG ‡ = 14.1 kcal/mol), although this step is endergonic by 10.3 kcal/mol (Fig. ). If an additional molecule of t BuOK reacts with the intermediate III′, the formation of carbanion species V′ and [( t BuO)2Bpin] -K + IV′ is thermodynamically favorable (ΔG = -19.7 kcal/mol) through a barrierless process (see Supplementary Fig. for calculated free energy profiles). These computational results suggest that the irreversible cleavage of C-B bond in benzylic organoboronates can be achieved by increasing the amount of alkoxide bases. To verify these mechanistic findings, we conducted some control experiments. According to the 11 B NMR analysis (in THF-d8) presented in Fig. , the signals of boron species depends on the amount of t BuOK. In the presence of 1.2 equivalent of t BuOK, two tetracoordinated boron resonances were detected at δ 6.9 and 4.3 ppm, which were assigned to the "ate" complex II′ and [( t BuO)2Bpin] -K + IV′, respectively, based on previous works and our present DFT calculations (shown in red numbers).