Synthesis of di/trifluoromethyl bis(1,2,4-triazoline)spiranes and 1,2,4-triazoles via 1,3-dipolar cycloaddition of nitrilimines and carbodiimides†

An efficient strategy for constructing di/trifluoromethyl bis(1,2,4-triazoline)spiranes and 1,2,4-triazoles via 1,3-dipolar cycloaddition reaction of nitrilimines and carbodiimides was developed. Various N-aryl di/trifluoromethyl acetohydrazonoyl bromides are well tolerated in the reaction, providing the target products in good regioselectivity and yields. This method features simple operation, high efficiency and mild reaction conditions for the rapid synthesis of complex fluoroalkylated nitrogen-rich spirocyclic compounds.