Rhodium-Catalyzed Selective Nucleophilic Cyclization/Cross-Coupling of Two ortho -Alkynylanilines Bearing Differential N -Substituents.

Herein, we reported an effective selective nucleophilic cyclization/cross-coupling cascade reaction of N -tosyl ortho -alkynylanilines and N -acyl ortho -alkynylanilines using Rh(COD) 2 BF 4 / t BuXantPhos as a catalyst. The present protocol features excellent chemo- and regioselectivity, high atom-economy, and a broad range of substrates. The mechanism studies indicated that the key to the success of this reaction is the powerful capacity of the rhodium catalyst to recognize the N -substituent group in the selective nucleophilic cyclization and selective alkyne insertion.