Department of Chemistry , Louisiana State University , 232 Choppin Hall , Baton Rouge , Louisiana 70803 , United States.
Département de Chimie Moléculaire, Université Grenoble Alpes, CNRS, UMR 5250 , F-38000 Grenoble , France.
J Org Chem. 2019 Jun 7;84(11):7166-7174. doi: 10.1021/acs.joc.9b00853. Epub 2019 May 16.
Our investigations on the reaction mechanism to account for regioselectivity on the addition of indoles to unsymmetrical silyloxyallyl cations are reported. Using both experimental and computational methods, we confirmed the significance of steric effects from the silyl ether group toward directing the inward approach of indoles, leading to nucleophilic attack at the less substituted electrophilic α'-carbon. The role of residual water toward accelerating the rate of reaction is established through stabilization of the participating silyloxyallyl cation.
我们对吲哚与不对称硅氧基烯丙基阳离子加成的区域选择性反应机制进行了研究。通过实验和计算方法,我们证实了硅醚基团的空间位阻对引导吲哚的内位进攻,导致亲核试剂进攻位阻较小的α'-碳的重要性。通过稳定参与反应的硅氧基烯丙基阳离子,确定了残留水对加速反应速率的作用。