Cycloaddition Reactions of Azides and Electron-Deficient Alkenes in Deep Eutectic Solvents: Pyrazolines, Aziridines and Other Surprises

Abstract

The reaction of organic azides and electron-deficient alkenes was investigated in a deep eutectic solvents. A series of highly substituted 2-pyrazolines was successfully isolated and their formation rationalised by DFT calculations. The critical effect of substitution was also explored; even relatively small changes in the cycloaddition partners led to completely different reaction outcomes and triazolines, triazoles or enaminones can be formed as major products depending on the alkene employed. (Figure presented.).