Transition Metal-and Oxidant-Free Regioselective Synthesis of 3,4,5-Trisubstituted Pyrazoles by Means of [3+2] Cycloaddition Reactions

摘要

A highly efficient regioselective synthesis of 3,4,5-trisubstituted pyrazoles via transition metal-and oxidant-free,three component [3+2] cycloaddition with thiazolidinedione chalcones,benzaldehydes and N-tosylhydrazine is described.The reaction proceeds through C-C and C-N bond formations under mild reaction conditions to produce structurally diverse polysubstituted pyrazoles in moderate to good yields.