Regioselective and stereoselective cyclizations of cyclohexadienones tethered to active methylene groups
作者:Rodolfo Tello-Aburto、Kyle A. Kalstabakken、Kelly A. Volp、Andrew M. Harned
DOI:10.1039/c1ob06125a
日期:——
of 2,5-cyclohexadienones tethered to activated methylene groups was studied. The substitution around the cyclohexadienone ring serves to regioselectively direct these cyclizations based primarily on electronic effects. In the case of brominated substrates, these reactions proceed to give highly unusual electron-deficient tricyclic cyclopropanes. By using a Cinchona alkaloid-based phase-transfer catalyst
研究了拴在活化亚甲基上的2,5-环己二酮的环化作用。主要基于电子效应,环己二烯酮环周围的取代用于区域选择性地引导这些环化反应。在溴化底物的情况下,这些反应会继续产生异常电子缺乏的三环环丙烷。通过使用基于金鸡纳生物碱的相转移催化剂,前手性环己二酮可以中等立体选择性地脱对称。