Subtle differences in reaction conditions facilitated unprecedented photocatalytic reactions of oxadiazolines by energy transfer catalysis. A set of compounds, sulfoximines and benzimidazoles, were ingeniously prepared from oxadiazolines via nitrene intermediates by photocatalytic N−O/C−N bond cleavages. The synthesis of sulfoximines was realized through intermolecular N−S bond formation between nitrene intermediates and sulfoxides, whereas benzimidazoles were obtained via intramolecular aromatic substitution of the nitrene to the tethered aryl substituent.

A nickel-catalyzed reductive coupling of alkynes and amides, followed by base-free transmetalation, proceeded selectively in the presence of an uncommon bidentate primary aminophosphine ligand to access highly functionalized indoles comprising biologically important trifluoromethyl groups and challenging electron-rich alkenyl groups at the 2- and 3-positions, respectively. Indole molecules were installed within natural products or drug molecules under mild conditions, and a trifluoromethylated analogue of a drug molecule (pravadoline) was also synthesized.

A simple photocatalytic method was developed for the synthesis of unsymmetrical 1,2-diamines by the unprecedented reductive coupling of N-benzylidene-[1,1'-biphenyl]-2-amines with an aliphatic amine. The presence of a phenyl substituent in the aniline moiety of the substrate was critical for the reactivity. The reaction proceeded via radical–radical cross-coupling of α-amino radicals generated by proton-coupled single-electron transfer in the presence of an Ir photocatalyst. On the other hand, symmetrical 1,2-diamines were selectively produced from the same starting materials by the judicious choice of the reaction conditions, showcasing the distinct reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines. The developed method can be employed for the synthesis of various bulky vicinal diamines, which are potential ligands in stereoselective synthesis.