Gold-catalyzed reaction of alkynes with diazonium salts under photoirradiation revisited: New alkoxyarylation variant leading to enol ethers

Since earlier work on the use of arenediazonium tetrafluoroborates under gold-photoredox co-catalyzed activation of alkynes has been developed using Ar3PAuCl salts, we focused on modifying the gold precatalyst. The use of the gold complex [Ph3PAuNTf2] allowed for a direct alkoxyarylation of alkynes to form enol ethers in a stereoselective manner, instead of the previously obtained ketones. The synthetic utility of these enol ethers was demonstrated with the controlled preparation of deuterated ketones and fluorinated ketals. Additionally, the mechanism of this alkoxyarylation variant has been explored with density functional theory (DFT) calculations. (C) 2020 Elsevier Inc. All rights reserved.