Electronic Dependence of C−O Reductive Elimination from Palladium (Aryl)neopentoxide Complexes
作者:Ross A. Widenhoefer、Stephen L. Buchwald
DOI:10.1021/ja9806581
日期:1998.7.1
decomposition of 1b−f obeyed first-order kinetics, and the rate of reductive elimination decreased in the order o-NO2 > p-NO2 > p-CHO > p-COPh > o-CN. Conversely, thermal decomposition of the related derivatives [P−P]Pd(Ar)OCH2CMe3 [P−P = Tol-BINAP or BINAP; Ar = p-C6H4Cl (1g), m-C6H4NO2 (1h), m-C6H4CN (1i)] which did not possess a resonance stabilizing group on the palladium-bound aryl group led to no detectable
钯(芳基)新五氧化物络合物的热分解 [P-P]Pd(Ar)OCH2CMe3 [P-P = Tol-BINAP 或 BINAP;Ar = p-C6H4CHO (1b), p-C6H4COPh (1c), p-C6H4NO2 (1d), o-C6H4NO2 (1e), o-C6H4CN (1f)] 在钯结合的芳基上具有适合于离域的取代基负电荷导致芳醚的定量 (≥95%) 形成而没有可检测的 β-氢化物消除。1b-f 的热分解服从一级动力学,还原消除速率按 o-NO2 > p-NO2 > p-CHO > p-COPh > o-CN 的顺序降低。相反,相关衍生物的热分解 [P-P]Pd(Ar)OCH2CMe3 [P-P = Tol-BINAP 或 BINAP;Ar = p-C6H4Cl (1g), m-C6H4NO2 (1h), m-C6H4CN (1i)] 在钯结合的芳基上不具有共振稳定基团,导致无法检测到芳醚的形成。