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A palladium-catalyzed (3 + 2) annulation of 2-methylbenzoic acid with maleimide using Ac-Leu-OH as a powerful ligand has been reported. Through a site-selective γ-C(sp 3 )-H olefination reaction and a sequential decarboxylative cross-coupling reaction, a five-membered cyclic ring was obtained as the final product. This novel reaction features great site selectivity and reactivity to generate various cyclic products in moderate to good yields.

Palladium-catalyzed sequential C(sp 3 )-H and C(sp 2 )-H bond diolefination reaction of o -toluidine has been realized for the first time using acetyl-protected aminoethyl phenyl thioether ligands. This novel reaction allows for preparation of the conjugated diene structure via an immediate second olefination on the basis of the first C(sp 3 )-H olefination in one pot. Various triflyl-protected anilines and acrylates were used as coupling partners elegantly. Furthermore, the unpurified diolefination products can be easily converted to tetrahydroquinoline derivatives.

In the presence of aldehyde, a facile method was developed to obtain N -sulfonyl amidines under metal- and oxidant-free conditions by the decarboxylative of proline. This transformation features a double C-N bond formation and allows for the green synthesis of the N -sulfonyl amidines on the basis of mild conditions.

The first intermolecular ring-opening hydroacylation of alkylidenecyclopropanes with chelating aldehydes through a rhodium-catalyzed acrylamide-promoted protocol is reported. This highly efficient catalytic system enables the direct synthesis of a diverse range of linear γ,δ-unsaturated ketones. Good functional group compatibility is demonstrated for the completely atom-economical and remarkably selective proximal C-C bond cleavage process. Mechanistic studies reveal that the bidentate coordination of N , N -dimethylmethacrylamide ( L1 ) to the acylrhodium intermediates might facilitate the cyclopropane ring fragmentation and isomerization.