A Convenient Wittig-Horner Mediated Synthesis of 3-Vinylsulfide Derivatives of Indoles

Abstract

A simple and robust coupling protocol is reported to provide the previously unknown indole derivatives carrying vinylsulfide motifs attached to C−3 of the heterocycle. The developed strategy involved a Wittig-Horner reaction with different phosphinoxide derivatives. The reaction conditions were optimized and its scope and limitations were assessed. The target compounds, including 3-arylvinylsulfides as well as symmetric and dissymmetric bis-vinylsulfides, were obtained in a straightforward way, as mixtures of geometric isomers, in good to excellent yields.