Intermolecular Gold(I)-Catalyzed Alkyne Carboalkoxylation Reactions for the Multicomponent Assembly of β-Alkoxy Ketones

A new gold(I)-catalyzed multicomponent synthesis of beta-alkoxy ketones from aldehydes, alcohols, and alkynes is described. This atom economical synthesis was achieved through the use of the gold complex (SPhos)AuNTf2 as a catalyst, and allows for the preparation of a diverse array of beta-alkoxy ketone products. Mechanistic studies illustrate that these reactions proceed via gold(I)-catalyzed hydrolysis of the alkyne to an aryl ketone, which then undergoes an aldol reaction with an oxocarbenium ion generated in situ from the aldehyde and alcohol components.