作者:Torben Rasmussen、Jakob F. Jensen、Niels Østergaard、David Tanner、Tom Ziegler、Per-Ola Norrby
DOI:10.1002/1521-3765(20020104)8:1<177::aid-chem177>3.0.co;2-h
日期:2002.1.4
addition of the very reactive metallacarbene intermediate in an early transition state to the substrate alkene is concerted but strongly asynchronous, with substantial cationic character on one alkene carbon in the neighborhood of the transition state. Evidence from isotope effects and Hammett studies supports the nature of the transition state. Formation of a metallacyclobutane intermediate by a [2+2] addition
通过实验和计算方法研究了重氮对映选择性铜催化的环丙烷化反应中的选择性决定步骤。处于早期过渡态的反应性很强的金属茂碳烯中间体向底物烯烃的添加是一致的,但强烈不同步,在过渡态附近的一个烯烃碳上具有实质性的阳离子特性。同位素效应和Hammett研究的证据支持过渡态的性质。在动力学上不利于通过添加[2 + 2]形成金属环丁烷中间体。已经鉴定出影响对映体和非对映体选择性的配体-底物相互作用,并且建议在添加过程中烯烃底物的优选取向。