【文章名】The subtle co-catalytic intervention of benzophenone in radical cation mediated cyclization - an improved synthesis of 2-(3',4'-dimethoxyphenyl)indoline.
The subtle co-catalytic intervention of benzophenone in radical cation mediated cyclization - an improved synthesis of 2-(3',4'-dimethoxyphenyl)indoline.
作者
Thomas, Noel Francis;Kee, Chin-Hui;Ariffin, Azhar;Awang, Khalijah;Faizal Weber, Jean-Frederic;Lim, Chuan-Gee;Mukhtar, Mat Ropi;Hadi, A. Hamid A.;
[摘要]：The addn. of benzophenone to a FeCl3/CH2Cl2 mixt. in the presence of 3',4'-dimethoxy-2-acetamidostilbene unexpectedly leads to a dramatic improvement in yield of the indoline from 38% (previously reported) to 75.4%, after careful examn. of a variety of reaction conditions. A catalytic cycle is proposed that involves not only stilbene radical cations but also Fe2+ promoted benzophenone ketyl radical formation which enhances cyclization, suppresses dimerization and accounts for the virtually quant. recovery of the benzophenone.
