Piperazine as Leaving Group in A3 Adducts: Fast Access to Alkynyl Indoles

Abstract

International audienceThe A3 coupling between N-ethylpiperazine and electron-rich aromatic aldehydes forms adducts that may be easily used as electrophiles towards electron-rich heterocycles such as indoles. The removal of the piperazine moiety is triggered by the addition of 1,2-dibromoethane. Overall, the reaction provides efficient access to alkynyl indoles and pyrroles