Mechanistic Perspectives in the Regioselective Indole Addition to Unsymmetrical Silyloxyallyl Cations

Caitlin G. Bresnahan, Louisiana State University
Kiara A. Taylor-Edinbyrd, Louisiana State University
Alexander H. Cleveland, Louisiana State University
Joshua A. Malone, Louisiana State University
Nitin S. Dange, Louisiana State University
Anne Milet, Universite Grenoble Alpes
Revati Kumar, Louisiana State University
Rendy Kartika, Louisiana State University

Abstract

© 2019 American Chemical Society. 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.