Sc(OTf) 3 -Mediated One-Pot Synthesis of 3,4-Disubstituted 1 H -Pyrazoles and 3,5-Disubstituted Pyridines from Hydrazine or Ammonia with Epoxides.

Here, we report the synthesis of 3,4-disubstituted 1 H -pyrazoles and 3,5-disubstituted pyridines from the reaction of epoxides with hydrazine and ammonia, respectively. Both reactions utilize Sc(OTf) 3 as a Lewis acid. The pyrazole synthesis utilizes N -bromosuccinimide to convert the intermediate pyrazolines to the pyrazoles, whereas the pyridine synthesis utilizes FeCl 3 as a cocatalyst.