An unusual transformation of 5-acyl-l,2,4-triazines into 3-pyridy1-1,2,4-triazines via tandem Stille cross-coupling/aza Diels-Alder reaction

摘要

A new route to 3-heteroaryl-l,2,4-triazines possessing a keto substituent at C-5 of the 1,2,4-triazine core using a Stille cross-coupling procedure and their unexpected ring transformation into pyridyltriazines as a result of enolization of an acyl group catalyzed by metal ions, are reported.