A system utilizing palladium(II)-PEG has been devised for the intramolecular Heck cyclization of N-vinyl and N-allyl-2-haloanilines. The synthesis of a variety of indoles, including 2,3-diester substituted ones and 3-methyl indoles, has been accomplished using this catalytic system. The N-vinyl starting materials are obtained by the aza-Michael addition of 2-haloanilines with alkynecarboxylate esters
设计了一种利用
钯( II )-P
EG 的系统,用于N-
乙烯基和N-烯丙基-2-卤代
苯胺的分子内 Heck 环化。利用该催化体系完成了多种
吲哚的合成,包括2,3-二酯取代
吲哚和
3-甲基吲哚。 N-
乙烯基起始材料通过2-卤代
苯胺与
炔烃羧酸酯的氮杂-迈克尔加成获得,其在环化后产生酯取代的
吲哚。相反, N-烯丙基-2-卤代
苯胺产生3-甲基化
吲哚作为主要产物。该系统的高活性归功于Pd纳米颗粒的原位生成。