We evaluated our investigation with a model reaction between 1-azadiene 1a and crotonate-derived sulfur ylide 2a in the presence of Cs2CO3 in dichloromethane at room temperature for 1 h to obtain nitrogen-heterocycles 3a (X-ray crystallographic analysis, CCDC 2145522) in 95% isolated yield (Table , entry 1). Some screening data of the reaction conditions were shown in Table . This reaction could not occur without base participated (entry 2). We changed the base to Et3N, DABCO, K2CO3, but an unsatisfactory result was acquired with the yield of 54%, 32%, 84% separately (entry 3). The different solvents such as MeCN, DMF also were investigated with the yield of 78%, 80% separately. When chose alcohols solvent such as MeOH, less than 5% of the product was obtained (entry 4). We tried to reduce the amount of base to 1.0 eq, but the yield was decreased correspondingly to 48% (entry 5). When the temperature was raised to 60 o C, we found that the raw material 2a began to decompose and the by-products began to increase. So that leads to a decrease in the 25% yield of 3a (entry 6). Reaction conditions: 1a (0.10 mmol, 1.0 eq), 2a (0.12 mmol, 1.2 eq), Cs2CO3 (0.20 mmol, 2.0 eq), DCM (0.5 mL), r.t, 1 h. N.D. = not detected. DMF = N, N'-dimethylforma. b Isolated yield was reported.