Gold catalysts have been applied in cascade-type reactions for the synthesis of different nitrogen-based compounds. The reactions likely proceed by a new gold-catalyzed cascade intermolecular α-amidoalkylation/intramolecular carbocyclization cascade process by unifying both the σ- and π-Lewis acid properties of the gold salts. In the first part of this report we show that the σ-Lewis acidity of gold(I) and gold(III) could be exploited to efficiently catalyze the nucleophilic substitution of various alkoxy- and acetoxylactams. The reaction was found to be applicable to a wide range of cyclic N-acyliminium ion precursors and various nucleophiles, including allyltrimethylsilane, silyl enol ethers, arenes, and active methylene derivatives. As a logical progression of this study, a combined hard/soft binary catalytic gold system was then used to implement an unprecedented tandem intermolecular Friedel-Crafts amidoalkylation/intramolecular hydroarylation sequence allowing an expedient access to new, complex, fused polyheterocyclic structures from trivial materials.

The combined use of Tf2NH and L(Au)(+)X(-) as a dual or binary catalytic system clearly improves the efficiency and enlarges the scope of the tandem intermolecular Friedel-Crafts α-amidoalkylation/intramolecular hydroarylation sequence, compared to an "all gold" multicatalysis approach.

Highly substituted pyrido[4,3‐b]indole derivatives were synthesized through a straightforward one‐pot silver‐catalyzed process involving 2‐alkynylindole‐3‐carbaldehyde oximes. The tandem cyclization/nucleophilic addition sequence was optimized and applied to a wide range of nucleophiles, which reacted regioselectively at the pyrido[4,3‐b]indole C4 position. The scope and limitations of the methodology were evaluated and the final compounds were obtained in fair to very good yields. This versatile method proved to be compatible with various chemical functionalities or (hetero)cycles.