Rhodium(iii)-catalyzed successive C(sp2)-H and C(sp2)-C(sp2) bond activation of aryl oximes: synthetic and mechanistic studies

Merging selective C-H cleavage with C-C cleavage in a tandem reaction has been a practical strategy that permits skeletal diversification from simple raw materials. Herein, we describe a rhodium(iii)-catalyzed redox-neutral reaction of aryl oximes and internal alkynes to generate novel N-(2-cyanoaryl) indanone imines. The deconstruction of aryl oximes delivers nitrile-containing molecules with good yields, regioselectivities and atom economy, with the generation of water as a sole by-product. The experimental and theoretical studies afford mechanistic insights into this transformation. Selective nitrogen-directed C(sp(2))-H cyclization and subsequent acetonitrile-enabled spiro-cyclization realize the effective C-C activation under mild conditions. The work achieves an attractive integration of C-H activation with C-C activation in oxime transformation.