College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang Province 325035, PR China.
Org Lett. 2012 Aug 3;14(15):3850-3. doi: 10.1021/ol301497v. Epub 2012 Jul 23.
DFT/M06 calculations were performed to investigate the mechanism of the Pt-catalyzed intermolecular cyclopropanation of propargyl ester containing diynes with styrene. The results show that the alkynyl Pt-carbenoid formed from proximal activation of the diyne is a more favorable productive intermediate for cyclopropanation, which occurs preferentially at the distal sp-hybridized carbon via an S(N)2'-type olefin addition. Notably, the widely accepted [1,3]-metallotropic shift of such an alkynyl metal carbenoid is found to be energetically demanding.
采用 DFT/M06 计算方法研究了 Pt 催化炔丙酯基二炔与苯乙烯的分子间环丙烷化反应的机理。结果表明，从二炔的近端活化生成的炔基 Pt-卡宾是环丙烷化反应更有利的生成中间体，它优先通过 S(N)2'-型烯烃加成在远端 sp 杂化碳原子上发生反应。值得注意的是，人们普遍认为的这种炔基金属卡宾的[1,3]-金属重排反应在能量上是不利的。
