Precise Control of Regioselective N¹ and N²-Alkylation of Benzotriazoles with α-Diazoacetates by Metalloporphyrin

Regioselective N-alkylation of benzotriazole is highly important to prepare biological materials. Herein, a series of A2B2-typed porphyrin and metalloporphyrin compounds were prepared. Catalytic results disclosed that Ir(III) pentafluorophenyl-substituted porphyrin promoted selective N2-alkylation of benzotriazole, and meanwhile, Fe(III) pyridine-substituted porphyrin accelerated N1-alkylation of benzotriazole. The metalloporphyrin could be used as a linker and inserted into a two-dimensional metal–organic framework; the resultant composite behaved as a heterogeneous catalyst, which could be recycled and reused for at least 6 times without any decrease of activity. This work demonstrates that the introduction of appropriate functional groups into metalloporphyrin at the meso-position is an effective strategy to regulate the reactivity and selectivity of N-substitution of benzotriazoles.