Synthesis of 1,3-diazaazulene derivatives of colchicinoids and isocolchicinoids via ipso- or tele-substitution-condensation with amidines
作者:Marino Cavazza、Francesco Pietra
DOI:10.1016/s0040-4020(98)00856-4
日期:1998.11
nsation products (e.g. 7) are best obtained from cycloheptatrienone-ring deactivated substrates (e.g. 4), whereas isomeric tele-substitution-condensation products (e.g. 13), are best accessible from cycloheptatrienone-ring activated substrates (e.g. 10). Hydroxylic solvents inhibit tele-substitution-condensation, arguably by undergoing protonation in preference of the intermediate σ adduct.
秋水仙碱和isocolchicinoids与无水苯,得到区域选择性1,3-二氮杂薁类衍生物脒缩合:本位3'-取代缩合产物(例如7),最好从cycloheptatrienone环得到的失活底物(例如4),而异构体远程3'-取代缩合产品(例如13)最好从环庚三烯酮环活化的底物(例如10)获得。羟基溶剂可以抑制远程取代缩合,这可以通过优先于中间σ加合物进行质子化来解决。