Efficient synthesis of pyrazoles: oxidative C-C/N-N bond-formation cascade.

Neumann JJ, Suri M, Glorius F

Abstract

A novel synthetic strategy for the synthesis of tetrasubstituted pyrazoles is provided. In an efficient CC/NN bond-formation cascade, enamines and nitriles are oxidatively coupled to deliver pyrazoles in good yields (see scheme). The ready availability of the starting materials, the high level of practicability of the reaction and work up, and the avoidance of hydrazine starting materials make the method attractive.