Metal-Free Construction of Multisubstituted Indolizines via Intramolecular Amination of Allylic Alcohols.

An intramolecular amination of allylic alcohols is developed as an efficient and general access to biologically important multisubstituted indolizines and their variants. Two metal-free synthetic platforms including using aqueous hydrochloric acid solution as the solvent and p -toluenesulfonic acid as the catalyst have been established, enabling the divergent synthesis of these valuable compounds in high yields.