Although the pioneering example of ortho metalation involving cleavage of C-H bonds was achieved using a nickel complex (Kleiman, J. P.; Dubeck, M. J. Am. Chem. Soc. 1963, 85, 1544), no examples of catalysis using nickel complexes have been reported. In this work, the Ni-catalyzed transformation of ortho C-H bonds utilizing chelation assistance, such as oxidative cycloaddition of aromatic amides with alkynes, has been achieved.

A new type of carbonylation of the ortho C-H bonds in aromatic amides 1, in which the pyridin-2-ylmethylamino moiety functions as a bidentate directing group, can be achieved. The presence of ethylene as a hydrogen acceptor and also of H(2)O, probably for the generation of an active catalytic species, is required. A wide variety of functional groups, including methoxy, amino, ester, ketone, cyano, chloro, and even bromo substituents, can be substituted for aromatic amides. The complex 9 was isolated by the stoichiometric reaction of 1b and Ru(3)(CO)(12), in which 1b binds to one Ru atom in the expected N,N fashion and the carbonyl oxygen binds to the other Ru atom as an O donor.

Oxidative coupling between C(sp(2))-H bonds and C(sp(3))-H bonds is achieved by the Ni(II)-catalyzed reaction of benzamides containing an 8-aminoquinoline moiety as the directing group with toluene derivatives in the presence of heptafluoroisopropyl iodide as the oxidant. The method has a broad scope and shows high functional group compatibility. Toluene derivatives can be used as the coupling partner in an unreactive solvent.

The rhodium(I)-catalyzed reaction of alkynes with 2-bromophenylboronic acids in the presence of paraformaldehyde resulted in a CO gas-free carbonylative cyclization, yielding indenone derivatives. [RhCl(BINAP)](2) and [RhCl(cod)](2) were responsible for the decarbonylation of formaldehyde and the subsequent carbonylation of alkynes with 2-haloboronic acids, respectively, leading to efficient whole carbonylation. Sterically bulky and electron-withdrawing groups on unsymmetrically substituted alkynes favored the alpha-position of indenones.