As part of a program aimed at generating
new heterocyclic frameworks
for medicinal chemistry exploration, an efficient approach to the
assembly of novel ring-fused pyridopyrimidinones was undertaken. Specifically,
a collection of 11<i>H</i>-pyrido[2,1-<i>b</i>]quinazoline-1,11(2<i>H</i>)-diones and 2,3-dihydropyrido[1,2-<i>a</i>]pyrrolo[3,4-<i>d</i>]pyrimidine-1,10-diones
was generated via a palladium-catalyzed, pyridine-directed, cyclocarbonylation
of 2-pyridyl-linked vinylogous amides and ureas in yields of up to
90%
