Thermal and photoinduced reduction of some benzyl bromides by an NAD(P)H model: the effect of electron withdrawing groups on mechanism and reactivity
作者:Hongyi Wang、Danmei Dai、Youcheng Liu、Qingxiang Guo
DOI:10.1016/s0040-4039(02)01825-7
日期:2002.10
1-benzyl-1,4-dihydronicotinamide (BNAH). Two different mechanisms were found, i.e. one-step hydride transfer (polar pathway) and multi-step sequence initiated by single electron transfer (SET pathway). The effect of electron-withdrawing groups on the reactivity of the substrates were discussed in terms of Hammett substituent constants, 13C NMR chemical shift values and cyclic voltammetric redox potentials
一系列化合物中,ö -bromomethylbenzylidene甲基-丙二腈(1),二甲基Ô溴甲基benzylidenemalonate(2)和甲基α氰基Ö -bromomethylcinnamate(3)一种由NAD在黑暗中和在照射下被减少(P)H模型,1-苄基-1,4-二氢烟酰胺(BNAH)。发现了两种不同的机理,即一步法氢化物转移(极性途径)和由单电子转移引发的多步序列(SET途径)。根据哈米特取代基常数,13 C NMR化学位移值和循环伏安氧化还原电势及其相关性,讨论了吸电子基团对底物反应性的影响。