1,3-C–H bond activation on a transient gallium(i)/isocyanate adduct

Abstract

Reaction of NacNacGa with phenylisocyante generates a transient species amenable to unusual 1,3-C–H bond addition of unactivated sp³ C–H and sp² C–H bonds of substrates featuring a hard donor atom. This reaction proceeds for pyridine oxide, dimethylsulfoxide, and dimethylacetamide, but not for pyridine, cyclohexanone, and ethyl acetate. C–H activation was also not observed for reactions with triethylphosphine oxide but, interestingly, in the presence of this compound isocyanate undergoes self-coupling on Ga(I) with a regioselectivity that is different when carried out in the absence of Et₃PO.