“…The optimization of reaction condition was carried out with respect to different Lewis acids, reaction temperatures and solvents. First, we screened different Lewis acids in 1,2-dichloroethane as solvent for nitro-Mannich reaction imine 1a at 80 °C (Table 1, entries 1, [11][12][13][14][15][16][17]. In the current transformation, the results showed that CoCl 2 and AgOTf , in contrast to the reaction timing, were competent catalysts to give good yields (Table 1, entries 1 & 13), whereas other Lewis acids (AgNO 3 , PdCl 2 , PdCl 2 (PPh 3 ) 2 ) were somewhat inferior (Table 1, entries14-16).…”