effective. For methylarenes there was no over-oxidation to the carboxylic acid contrary to what was observed for nitric acid as oxidant. The conversion to the aldehyde/ketone could be increased by the addition of water to the reaction mixture. As evidenced by IR and (15)N NMR spectroscopy, initially the nitrate salt reacted with H(5)PV(2)Mo(10)O(40) to yield a N(V)O(2)(+)[H(4)PV(2)Mo(10)O(40)] intermediate
在 Keggin 型
钼基杂多酸 H(3+)(x)()PV(x)()Mo(12) 存在下,烷基
芳烃在
乙酸中被
硝酸盐催化和选择性氧化为相应的
乙酸苄酯和羰基产物)(-)(x)()O(40) (x = 0-2)。H(5)PV(2)Mo(10)O(40) 特别有效。对于甲基
芳烃,与
硝酸作为氧化剂所观察到的情况相反,
羧酸没有过度氧化。向反应混合物中加入
水可以提高醛/酮的转化率。IR 和 (15)N NMR 光谱证明,最初
硝酸盐与 H(5)PV(2)Mo(10)O(40) 反应生成 N(V)O(2)(+)[H (4)PV(2)Mo(10)O(40)]中间体。在电子转移反应中,提出的 N(V)O(2)(+)[H(4)PV(2)Mo(10)O(40)] 络合物与烷基
芳烃底物反应,产生基于自由基阳离子的供体-受体中间体, N(IV)O(2)[H(4)PV(2)Mo(10)O(40)]-ArCH(2)R(+)(