Preparation of pyridopyrazines through tandem Pd-catalyzed C–N/C–C coupling reactions of Ugi adducts†
Abstract
A Pd-catalyzed selective tandem cyclization of the Ugi adduct via Buchwald–Hartwig/C–H bond functionalization reactions has been reported. This sequence offers an interesting approach for synthesizing a wide range of pyrido[1,2-a]pyrazine-3,6-dione scaffolds under mild reaction conditions in moderate to excellent yields. The scope and limitations of the protocol are discussed.