Unexpected one-pot synthesis of new polycyclic coumarin[4,3-c]pyridine derivatives via a tandem hetero-Diels-Alder and 1,3-dipolar cycloaddition reaction
Keywords: 1-Azadienes; Azomethine ylide; Coumarins; 1,3-Dipolar cycloadditions; Hetero-Diels-Alder reactions; Pyridocoumarins;