Carbene and Acid Cooperative Catalytic Reactions of Aldehydes and <i>o</i>-Hydroxybenzhydryl Amines for Highly Enantioselective Access to Dihydrocoumarins
作者:Xingkuan Chen、Runjiang Song、Yingguo Liu、Chong Yih Ooi、Zhichao Jin、Tingshun Zhu、Hongling Wang、Lin Hao、Yonggui Robin Chi
DOI:10.1021/acs.orglett.7b02883
日期:2017.11.3
A highly enantioselective method for quick access to dihydrocoumarins is reported. The reaction involves a cooperative catalytic process with carbene and in situ generated Brønsted acid as the catalysts. α-Chloro aldehyde and readily available and stable o-hydroxybenzhydryl amine substrates were used to generate reactive azolium ester enolate and ortho-quinone methide (o-QM) intermediates, respectively
报道了一种快速对映二氢香豆素的高度对映选择性的方法。该反应涉及使用卡宾和原位生成的布朗斯台德酸作为催化剂的协同催化过程。使用α-氯醛和易于获得且稳定的邻羟基苯甲胺底物分别生成反应性的氮鎓烯醇酯烯醇盐和邻醌甲基化物(o- QM)中间体,以形成具有极高非对映选择性和对映选择性的二氢香豆素。催化反应产物可以容易地转化为有价值的药物和生物活性分子。