A cationic iridium-catalyzed C2-alkylation of N-substituted indole derivatives with various alkenes has been developed, which selectively gives linear or branched 2-alkylindoles in high to excellent selectivity. This protocol relies on the use of the carbonyl group on the nitrogen atom of indole as a directing group: a linear product was predominant when an acetyl group was used as a directing group, and a branched product was predominant with a benzoyl group.

A cationic Ir(I)-tolBINAP complex catalyzed an enantioselective C-C bond formation initiated by secondary sp(3) C-H bond cleavage adjacent to a nitrogen atom. The reaction of 2-(alkylamino)pyridines with various alkenes gave chiral amines in good yields with high enantiomeric excesses.

Over the past few years, iridium complexes have been widely used in the direct functionalization of unactivated bonds. In the presence of iridium catalysts, inactive C–H and N–H bonds have been transformed into C–C and N–C bonds in dehydrative alkylation using alcohols, allylation using allyl carbonates, and alkylation using alkenes. Enantioselective variants of some reactions have also been reported.

Azole derivatives were synthesized by iron-catalyzed oxidative reactions of azoles and ethers in good to excellent yields. A wide variety of azoles and ethers were selectively transformed into the corresponding oxidative coupling products under neutral reaction conditions.

A novel Pummerer-type reaction was developed via o-chloranil-mediated C-H bond oxidation. The reaction provides a simple and efficient method to construct sulfide derivatives. A Knoevenagel-type reaction was also achieved via multiple C-H bonds activation under neutral reaction conditions.