An ovel rhodium-catalyzed highly selective N 2alkylation of benzotriazoles with diazoc ompounds/enynones is achieved,p roviding N 2 -alkylated benzotriazoles in good to excellent yields and with excellent N 2 selectivities.Importantly, different to traditional carbene insertion into XÀH( X= N, O etc) bonds,D FT calculations disclose that this selective N 2alkylation probably proceeds through aformal 1,3-rather than 1,2-H shift to give the final products.

An ovel rhodium-catalyzed dearomatization of Osubstituted pyridines to access N-substituted 2-pyridones has been developed. Acomputational study suggests amechanism involving the formation of ap yridinium ylide followed by an unprecedented 1,4-acyl migratory rearrangement from OtoC. Furthermore,t he chiral dirhodium complexes serve as the catalyst for the asymmetric transformation with excellent enantioselective control. DFT calculations indicate the chirality is transferred from axial chirality to the central stereogenic centre.T he stronger p-p interaction and CH-p interaction account for the high enantioselectivity.Scheme 1. Previous reports and our new strategy.