Base-Controlled Divergent Synthesis of 5-Cyanobenzoxepines and Benzofuro[2,3-<i>b</i>]pyridines from 2-Bromophenylacetonitriles and Ynones
作者:Lu-Lu Chen、Jing-Wen Zhang、Pei Chen、Shuai Zhang、Wan-Wan Yang、Ji-Ya Fu、Jun-Yan Zhu、Yan-Bo Wang
DOI:10.1021/acs.orglett.9b01700
日期:2019.7.19
2-bromophenylacetonitriles and ynones has been developed. Various functionalized 5-cyanobenzoxepines and benzofuro[2,3-b]pyridines were obtained with a broad substrate scope and high regioselectivity in moderate to excellent yield. Of importance, an unexpected O-rearrangement reaction to access benzofuro[2,3-b]pyridines was observed using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as the base, and the possible mechanism
已经开发出一种有效的碱控制的2-溴苯基乙腈和炔酮的发散环化反应。获得了各种官能化的5-氰基苯并pine庚因和苯并呋喃[2,3- b ]吡啶,它们具有较宽的底物范围和较高的区域选择性,且产率中等至优异。重要的是,使用1,8-二氮杂双环[5.4.0]十一碳-7-烯(DBU)作为碱,观察到了意外的O重排反应,可接近苯并呋喃[2,3- b ]吡啶。由18个O标记的实验支持。另外,研究了克级合成和产物的进一步转化。