Carbon–Carbon Bond Forming Reactions of Vinyl Cations: A Personal Perspective

Abstract

Vinyl cations were first proposed as reactive intermediates nearly eighty years ago by Jacobs, and their properties were closely studied in the second half of the twentieth century by Stang, Olah, Caple, Grob, Hanack, and others. Recent developments in the catalytic generation and reactions of vinyl cations with unactivated C(sp3) −H bonds prompted us to assemble a field guide based on our previous experiences that is geared for synthetic chemists who are looking to construct C−C bonds via vinyl cation C−H insertion or Friedel-Crafts addition. In particular, this article focuses on silylium- and lithium-initiated C−C bond forming reactions of vinyl cations generated from vinyl triflates and ultimately aims to provide the reader with context and accelerate their selection of optimal reaction conditions and starting materials.