Aromatic Cyanoalkylation through Double C–H Activation Mediated by Ni(III)

Herein we report
an atom- and step-economic aromatic cyanoalkylation
reaction that employs nitriles as building blocks and proceeds through
Csp2–H and Csp3–H bond activation steps mediated by NiIII. In
addition to cyanomethylation with MeCN, regioselective α-cyanoalkylation
was observed with various nitrile substrates to generate secondary
and tertiary nitriles. Importantly, to the best of our knowledge these
are the first examples of C–H bond activation reactions occurring
at a NiIII center, which may exhibit different reactivity
and selectivity profiles than those corresponding to analogous NiII centers. These studies provide guiding principles to design
catalytic C–H activation and functionalization reactions involving
high-valent Ni species.