Domino process in silver-catalyzed reactions of N-arylformimidates and active methylene compounds involving cycloisomerization and 1,3-alkenyl shift.

We have developed an efficient method for the synthesis of 2,3-disubstituted indoles from alkyne iminoethers 1 that employs a domino process involving Ag-catalyzed condensation followed by a tandem Ag-induced cycloisomerization and 1,3-alkenyl shift to Ag-activated carbon. This methodology can be useful in regioselectively constructing 3-alkylated indoles, which are part of the structures of biologically active compounds and important alkaloids.