An efficient synthesis of N-fused polycyclic and 2,3-disubstituted indoles by copper-catalyzed direct annulation/acyl migration reaction of enaminones is reported. This strategy features cheap and low loading of the catalyst/ligand, readily available starting materials, and good functional group compatibilities. Notably, allyl-containing substrates are also tolerated, which allows the downstream derivatization toward indole alkaloids.

An efficient synthesis of N-fused polycyclic indoles by a palladium-catalyzed annulation/acyl migration cascade reaction is described. The reaction is ligand-free, scalable, and provides access to a diverse range of useful indole scaffolds from readily available starting materials. Supporting mechanistic studies indicate that the reaction likely proceeds via an intramolecular α-arylation mechanism. The synthetic utility of this protocol is demonstrated by a gram-scale reaction and syntheses toward indole alkaloids and a HSP90 inhibitor.

A copper-catalyzed annulation of alkyne-tethered enaminones for the synthesis of 2,3-ring fused pyrroles is reported. The 5-exo-dig cyclization/olefin migration reaction delivers the multisubstituted pyrroles in 59–99% yields with 16 examples. This strategy features easily available starting materials, mild reaction conditions, and a cheap ligand-free copper catalyst. The atom-economic transformation provides a simple access to a variety of synthetic useful pyrroles and their derivatives.

A two-component and metal-free azidotrifluoromethylation of alkenes is realized using readily synthesized trifluoromethanesulfonyl azide (N3SO2CF3) as a bifunctional reagent for both CF3 and N3 groups.

An efficient aminochlorination reaction of stryenes is described using N3SO2CF3 as an amination reagent and FeCl2 as a chloride source. The operationally simple procedure features mild reaction conditions, good functional group compatibility, and high regioselectivity. An example of aminobromination using FeBr2 is also realized. Additionally, a one-pot aminoazidation of styrenes is achieved by adding sodium azide to the reaction. The gram-scale synthesis and downstream derivatization of the products are showcased as well.

An enantioselective palladium-catalyzed annulation of alkyne-tethered malononitriles for the synthesis of 3,4-ring-fused isocoumarins is described. This cascade strategy involves oxypalladation of ortho-alkynylbenzoates and desymmetrizing addition onto one cyano group of the pendant malononitriles, which enables the concurrent construction of two rings and an all-carbon quaternary stereocenter in a single operation.

An enantioselective and catalytic method for the synthesis of bridgehead quaternary carbon containing bicyclo[3.3.1]nonanes is described. The intramolecular desymmetric arylation of α-disubstituted 1,3-diketones was achieved using a chiral Pd/PHOX complex. A variety of bridged cyclic molecules, common skeleton for polyprenylated acylphloroglucinols, were obtained in up to 84% yield with 86% ee.

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