Nickel-catalyzed chelation-assisted transformations involving ortho C-H bond activation: regioselective oxidative cycloaddition of aromatic amides to alkynes.

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.

Ruthenium-catalyzed carbonylation at ortho C-H bonds in aromatic amides leading to phthalimides: C-H bond activation utilizing a bidentate system.

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.