A versatile rhodium-catalyzed/copper-mediated C–H/C–C activation and cascade annulation reaction was described to form 2-arylindole derivatives. Highly selective C–C bond cleavage of γ-substituted tert-propargyl alcohols occurred, together with pyridine-directed ortho C­(sp2)–H bond activation, affording a series of 2-arylindoles with yields up to 90%. Subsequent derivations were smoothly conducted to access polyfunctionalized 2-arylindoles, illustrating the potential applications of this method.

A rhodium-catalyzed Suzuki–Miyaura coupling reaction via C­(O)-C bond activation to form 2-benzoylpyridine N-oxide derivatives is reported. Both the C­(O)–C­(sp2) and C­(O)–C­(sp3) bond could be activated during the reaction with yields up to 92%. The N-oxide moiety could be employed as a traceless directing group, leading to free pyridine ketones.

Amidation of nitrile with N,N-dimethylformamide (DMF) was catalyzed by Cu2O with 1,10-phenanthroline as a ligand under an oxygen atmosphere. A variety of N,N-dimethyl benzamides were obtained in yields up to 84%.

The use of ketones as electrophiles to couple with arylboronic acid derivatives via CÀ C bond activation has become a significant progress in the area of Suzuki-Miyaura coupling (SMC) reaction, in which a permanent or temporary directing group is often required to promote the activation of the unstrained CÀ C bond via oxidative addition. Herein, we disclosed the first example of directing group free formal SMC reaction of simple ketones with arylboronates via Rhcatalyzed unstrained CÀ C bond activation. A wide range of simple ketones, including aryl alkyl ketones, diaryl ketones and aryl perfluoroalkyl ketones, can serve as electrophiles to participate in the SMC reaction with aryl or perfluoroalkyl as the leaving group. The key to the success of this reaction is by means of nucleophilic addition/β-carbon elimination sequence that can activate the unstrained ketone carbonyl CÀ C bond without the assistance of directing group.

A chelation-assisted palladium-catalyzed CC bond cleavage of α, β-unsaturated ketone to form alkenyl nitrile in the presence of nitrile is disclosed on the basis of a formal group-exchange reaction formulated as C1C2 + C3 → C1C3 + C2, differing from normal alkene oxidative cleavage and metathesis type. The isolated key active Pd­(II) complex as well as deuterium-labeled experiment revealed the necessity of the chelation group, and a plausible catalytic pathway was proposed.