Organocatalytic, Enantioselective, Intramolecular Oxa-Michael Reaction of Alkoxyboronate: A New Strategy for Enantioenriched 1-Substituted 1,3-Dihydroisobenzofurans
作者:Barnala Ravindra、Braja Gopal Das、Prasanta Ghorai
DOI:10.1021/ol502614n
日期:2014.11.7
An unprecedented strategy for the synthesis of enantioenriched 1-substituted 1,3-dihydroisobenzofurans via an enantioselective oxa-Michael reaction of o-alkoxyboronate containing chalcone (II) has been accomplished employing cinchona alkaloid based squaramide bifunctional organocatalyst in the presence of proton source. The corresponding alkoxyboronate intermediates have been readily prepared in situ
在质子源存在下,使用基于金鸡纳生物碱的方酰胺双功能有机催化剂,通过含有查耳酮 ( II ) 的邻烷氧基硼酸酯的对映选择性 oxa-Michael 反应,实现了合成对映体富集的 1-取代 1,3-二氢异苯并呋喃的前所未有的策略。使用中性硼烷作为氢化物源和作为催化剂对应物的叔胺部分,可以容易地由邻甲酰基查尔酮原位制备相应的烷氧基硼酸酯中间体。