Computational and experimental studies on Cu/Au-catalyzed stereoselective synthesis of 1,3-disubstituted allenes

Abstract

Thorough mechanistic investigation unveils details of the allenylation of terminal alkynes (ATA) under Crabbé-like conditions allowing for an enantioselective approach.

Gold‐Catalyzed One‐Pot Synthesis of 1,3‐Disubstituted Allenes from Benzaldehydes and Terminal Alkynes

“…In analogy to the reported Crabbé-like process promoted by zinc iodine [7a] and related processes, [15] we suggest that the formation of the allenes 5 from morpholine 2 and alkyne 3 happens in a multistep process in which, at first, a A 3 coupling reaction takes place and, the formed propargylamine 4 t then reacts further to generate the allene 5 a. It is necessary to stress that the propargylamine has been isolated during the optimization of the reaction conditions, but to prove its participation as a reaction intermediate, propargylamine 4 a was synthesized and, after isolation, submitted to our standard reaction conditions.…”