Gold(I)-Catalyzed Synthesis of Tetrahydrocarbazoles via Cascade [3,3]-Propargylic Rearrangement/[4+2] Cycloaddition of Vinylindoles and Propargylic Esters

A gold(I)-catalyzed cascade [3,3]-propargylic rearrangement and [4+2] cycloaddition reaction of 2-vinylindoles with propargylic esters is reported. The reaction leads to the synthesis of highly substituted tetrahydrocarbazole derivatives in high yields and diasteroselectivities. Furthermore, a preliminary screening for an asymmetric version of this reaction is described.