Table 2. Scope of the Zn(II)-Catalyzed [3 + 2] Cycloaddition Reaction of 2,3-Substituted Indoles (1) and Linear Azoalkenes (2)^a,b.

^aReaction conditions: 1 (0.6 mmol), 2 (0.4 mmol), ZnCl₂ (0.04 mmol, 10 mol %), DCM (2.0 mL), 25 °C.

^bIsolated yields.