Stereoselective Formation of a Chiral Ether by Intramolecular O–H Insertion Reaction of a Metal Carbenoid Generated from Diazoacetoacetate
作者:Chun Young Im、Tadashi Okuyama、Takashi Sugimura
DOI:10.1002/ejoc.200700759
日期:2008.1
Intermolecular O–H insertion reactions of rhodium carbenoids generated from chiral diazoacetoacetates are less efficient and less stereoselective than the reactions of those generated from the corresponding phenyldiazoacetates. Nevertheless, when the diazoacetoacetate is connected to a phenolic moiety through a 2,4-pentanediol tether, the carbenoid generated shows a high potential in both efficiency
与由相应的苯基重氮乙酸酯产生的反应相比,由手性重氮乙酰乙酸酯产生的铑卡宾的分子间 O-H 插入反应的效率和立体选择性较低。然而,当重氮乙酰乙酸酯通过 2,4-戊二醇系链连接到酚类部分时,生成的类卡宾在分子内 O-H 插入反应中显示出高效率和立体选择性的潜力,可生成高达 88% 的环醚定量收率中的非对映体过量 (de)。de 值取决于系链的结构,但与使用的催化剂无关。在相应烯醇化物的平衡和动力学质子化条件下研究了环醚的异构化。