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 iridium‐catalyzed C‐7 alkylation of N‐substituted indoline derivatives with various alkenes has been developed. A variety of 7‐alkylindolines were obtained in moderate to high yields. This protocol relies on the use of the carbonyl group on the nitrogen atom of indoline as a directing group and it is potentially applicable to the large‐scale synthesis of 7‐alkylindoles.magnified image

A cationic Ir(I) complex-catalyzed O-to-N-alkyl migration in 2-alkoxypyridines bearing a secondary alkyl group on the oxygen atom by C-O bond cleavage is described. The present transformation gave various N-alkylpyridones in moderate to good yields. The addition of sodium acetate played a key role in suppressing β-hydrogen elimination.

Intramolecular enantioselective alkylation of N-alkenylindoles proceeded via C À H bond cleavage at the C-2 position in the presence of a cationic iridium catalyst with a diphosphine ligand. Aroyl groups at the C-3 position of the indoles operated as effective directing groups, and chiral 1-substituted-2,3-dihydro-1H-pyrrolo[1,2-a]indoles were obtained in high yield with excellent ee.

An efficient method for C7-position-selective alkenylation of N-substituted indolines with alkenes is reported. Various 7-alkenylindolines were obtained in moderate to excellent yields in air in the presence of catalytic amounts of [Cp*IrCl2]2, AgOTf, and Cu(OAc)2. The protocol relies on the use of a carbonyl or carbamoyl group on the nitrogen atom of indoline as a directing group and is potentially applicable to the synthesis of 7-alkenylindoles and 7-alkylindoles.