Gold-Catalyzed Tandem Reactions of 2-Alkynyl Arylazides and Carboxylic Acids for the Synthesis of 1H-Indol-3-yl Esters

Abstract

1H-Indol-3-yl acetates are very important indole derivatives, which can be found in many bioactive compounds and natural products. In this work, 1H-indol-3-yl acetates were efficiently prepared via α-imino gold carbenes generated by gold-catalyzed reactions of 2-alkynyl arylazides. A very simple and general method for the synthesis of 1H-indol-3-yl acetates was provided after examining the substrates scope.

Recent Progress in the Transition Metal Catalyzed Synthesis of Indoles

“…When R was an alkyl group the yields we cyclopropyl, H and with oxetane, tetrahydrofuran, 2-phenyloxirane, the reactio f unknown side products. Moreover, in the reaction with 4,6-dichloro substituted a -phenyl-1H-indol-3-ylmethanesulfonate was recovered in a 29% yield as a side anism depicted in Scheme 25 was proposed by authors, but without experimental Zhang had reported the gold-catalyzed tandem reactions of 2-alkynylarylazides with carboxylic acids [49]. Continuing his study in the time range of this review, he and his coworkers attempted the same tandem reaction with methane sulfonic acid in dioxane under t-BuXPhosAuNTf 2 , catalysis [50].…”