Enantioselective Conjugate Addition‐Protonation of 5
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‐Oxazol‐4‐ones and 5‐Methylene 1,3‐Oxazolidine‐2,4‐diones: 2,2'‐Biphenol‐Induced Diastereoselectivity Switch
作者:Bohua Lu、Shuang Xin、Bo Zhu、Junbiao Chang
DOI:10.1002/cjoc.201900111
日期:2019.7
asymmetric conjugate addition‐protonation and diastereoselective switch between 5H‐oxazol‐4‐ones and 5‐methylene 1,3‐oxazolidine‐2,4‐diones was established. An array of chiral conjugate addition‐protonation products bearing 1,3‐O‐heterotertiary‐O‐heteroquarternary nonadjacent stereocenters were obtained in excellent yields, moderate to good diastereoselectivities, and excellent enantioselectivities (up to
建立了在5 H-恶唑-4-酮和5-亚甲基1,3-恶唑烷-2,4-二酮之间进行催化不对称共轭加质子化和非对映选择性转换的合成策略。手性共轭加成质子化轴承产品的阵列1,3- ö -heterotertiary- ö -heteroquarternary不相邻的立体中心以优良产率获得,中度至良好非对映选择性,和优异的对映选择性(高达97%的收率,11:1个DR和98%ee)。2,2'-双酚的诱导可通过环加成中间体有效地促进相应非对映异构体的产生。