A synthetic method to prepare 1,2,3,5-tetrahydrobenzo[ g]quinolines efficiently that relies on gold(I)-catalyzed cycloisomerization of 5-(ethynylamino)pent-2-yn-1-yl esters at room temperature under atmospheric conditions is described. The proposed reaction mechanism presents a unique instance of an in situ formed allenic ester and gold keteniminium species to undergo a formal [4 + 2] cycloaddition pathway.

A synthetic method that relies on [Au2(-dppm)2]Cl2 (dppm = bis(diphenylphosphanyl)methane) and UVA LED (LED = light emitting diode) light ( = 365 nm) to mediate the -alkynylation of tertiary -silylamines...