文摘
Herein we report the synthesis and reactivity of several organometallic Nip>IIIp> complexes stabilized by a modified tetradentate pyridinophane ligand containing one phenyl group. A room temperature stable dicationic Nip>IIIp>鈥揹isolvento complex was also isolated, and the presence of two available cis coordination sites in this complex offers an opportunity to probe the C-heteroatom bond formation reactivity of high-valent Ni centers. Interestingly, the Nip>IIIp>-dihydroxide and Nip>IIIp>-dimethoxide species can be synthesized, and they undergo aryl methoxylation and hydroxylation that is favored by addition of oxidant, which also limits the 尾-hydride elimination side reaction. Overall, these results provide strong evidence for the involvement of high-valent organometallic Ni species, possibly both Nip>IIIp> and Nip>IVp> species, in oxidatively induced C-heteroatom bond formation reactions.