The study commenced with the reaction of o-hydroxy aromatic aldimine 1a and ethenesulfonyl fluoride 2a. Under the catalysis of 20 mol% triethylamine, this tandem reaction proceeded smoothly in acetonitrile at ambient temperature to produce sulfochromeno [4,3-b] pyrrolidine 3a in 57% yield (Table , entry 1). We assumed the acidic HF that generated in the SuFEx step neutralized the base, and quenched the reaction. As anticipated, increasing the amount of triethylamine to 0.5 equivalent, the yield of 3a was dramatically to 89% (Table ). Further increasing triethylamine to 0.8 equivalent led to slightly higher yield (Table 3). However, using 1.0 equivalent base cannot give a higher yield. The Hünig's base catalyzed the reaction in 93% yield ( With the optimal conditions in hand (Table , entry 16), we subsequently examined the scope and generality of the reaction. As shown in Table , a variety of differently substituted β-aryl ethenesulfonyl fluorides underwent the tandem [3+2] cyclization/SuFEx click reaction to produce the corresponding products in high yields (Table ). In addition, different electronic properties and varied positions of the substituents on the β-aryl rings have no obvious influence on the reaction yield (Table , 3a-3o). Both α-naphthyl and β-naphthyl substituted ethenesulfonyl fluoride 2p and 2q were proved to be very good dipolarophiles for the reaction, producing the corresponding products 3p and 3q in 99% and 84% yield, respectively. 2-Thienyl substituted ethenesulfonyl fluoride 2r couple with imine 1a to afford the fused heterocycle in 54% yield (Table , 3r).