Photochemical Generation and the Reactivity of <i>o</i>-Naphthoquinone Methides in Aqueous Solutions
作者:Selvanathan Arumugam、Vladimir V. Popik
DOI:10.1021/ja9031924
日期:2009.8.26
efficient (Phi(254) = 0.17 and 0.20) dehydration and the formation of isomeric naphthoquinone methides, 2,3-naphthoquinone-3-methide (1) and 1,2-naphthoquinone-1-methide (2), respectively. In aqueous solution, naphthoquinone methides 1 and 2 undergo rapid hydration to regenerate starting materials (tau(H2O) (1) = 7.4 ms and tau(H2O) (2) = 4.5 ms at 25 degrees C). The hydration reaction is strongly
辐照 3-羟基-2-萘甲醇 (3a) 和 2-羟基-1-萘甲醇 (4a) 导致高效(Phi(254) = 0.17 和 0.20)脱水并形成异构萘醌甲基化物,2,3-萘醌-3-methide (1) 和 1,2-naphthoquinone-1-methide (2),分别。在水溶液中,萘醌甲基化物 1 和 2 经历快速水合以再生起始材料(tau(H2O) (1) = 7.4 ms 和 tau(H2O) (2) = 4.5 ms 在 25 摄氏度)。水合反应由氢氧根离子强烈催化,但仅在 pH < 1 时才显示出酸催化作用。反应性中间体 1 和 2 可以被其他亲核试剂拦截,例如叠氮离子 (k(N3)(1) = 2.0 x 10( 4) M(-1) s(-1) 和 k(N3)(2) = 3.0 x 10(4) M(-1) s(-1)) 或硫醇 (k(SH)(1) = 2.2 x 10(5) M(-1)