Chiral Brønsted Acid-Promoted Enantioselective Desymmetrization in an Intramolecular Schmidt Reaction of Symmetric Azido 1,3-Hexanediones: Asymmetric Synthesis of Azaquaternary Pyrroloazepine Skeletons
作者:Ming Yang、Yu-Ming Zhao、Shu-Yu Zhang、Yong-Qiang Tu、Fu-Min Zhang
DOI:10.1002/asia.201100171
日期:2011.6.6
The enantioselective desymmetrization of 2‐substituted‐2‐azidopropyl 1,3‐hexanediones through an asymmetric intramolecular Schmidt reaction using a chiral Brønsted acid has been developed for the first time. Synthetically interesting pyrroloazepine skeletons with an azaquaternary stereogenic center with up to 59 % ee are accessed effectively (see scheme; R=H, alkyl, or aryl).
首次开发了使用手性布朗斯台德酸通过不对称分子内Schmidt反应对2-取代2-叠氮丙基1,3-己二酮进行对映选择性脱对称。合成有趣的吡咯并ze庚因骨架,其氮杂季铵立体异构中心的ee高达59%(请参阅方案; R = H,烷基或芳基)。