Structural and mechanistic studies of the base-induced Sommelet–Hauser rearrangement of N-α-branched benzylic azetidine-2-carboxylic acid-derived ammonium salts
作者:Eiji Tayama、Kazutoshi Watanabe、Sho Sotome
DOI:10.1039/c7ob01391d
日期:——
The base-induced Sommelet–Hauser rearrangement of N-α-branched benzylic azetidine-2-carboxylic acid ester-derived ammonium salts to obtain α-arylazetidine-2-carboxylic acid esters was investigated. The substrates, two diastereomeric salts (1S,2S,1’S)- and (1R,2R,1’S)-2, showed different reactivities. The rearrangement of (1S,2S,1’S)-2a proceeded with a perfect N-to-C chirality transfer to provide (R)-3a
研究了碱诱导的N-α-支化苄基氮杂环丁烷-2-羧酸酯衍生的铵盐的Sommelet-Hauser重排,以获得α-芳基氮杂环丁烷-2-羧酸酯。底物,两种非对映异构盐(1S,2S,1'S)-和(1R,2R,1'S)-2显示不同的反应性。(1S,2S,1'S)-2a的重排进行了从N到C的完美手性转移,从而以74%的收率和99%的ee提供了(R)-3a。但是,在相同条件下(1R,2R,1'S)-2a的重排仅能以15%的收率提供(S)-3a,而ee却低至66%,还有竞争性的[1,2]史蒂文斯重排产物4a。对这种重排进行了结构和机理研究,以弄清确切原因。