The ketene-surrogate coupling: catalytic conversion of aryl iodides into aryl ketenes through ynol ethers

Abstract

tert-Butoxyacetylene is shown to undergo Sonogashira coupling with aryl iodides to yield aryl-substituted tert-butyl ynol ethers. These intermediates participate in a [1,5]-hydride shift, which results in the extrusion of isobutylene and the generation of aryl ketenes. The ketenes are trapped in situ with multiple nucleophiles or undergo electrocyclic ring closure to yield hydroxynaphthalenes and quinolines.

Keywords: arenes; cross-coupling; ketenes; palladium; synthetic methods.