Selective benzylic C sp3 -H bond activations mediated by a phosphorus-nitrogen PN 3 P-nickel complex.

In contrast to the typical C sp2 -H activation, a PN 3 P-Nickel complex chemoselectively cleaved the benzylic C sp3 -H bond of toluene in the presence of KHMDS, presumably via an in situ generated potassium benzyl intermediate. Under similar conditions, CO underwent deoxygenation to afford the corresponding nickel cyano complex, and ethylbenzene was dehydrogenated to give styrene and a nickel hydride compound. 2,6-Xylyl isocyanide was transformed into an unprecedented indolyl complex, likely by trapping the activated benzyl species with an isocyanide moiety.