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.