Efficient generation of highly functionalized fused oxazepine frameworks based on a CAN-catalyzed four-component tetrahydropyridine synthesis/ring-closing metathesis sequence.

1-Allyl(propargyl)-6-allyl(propargyl)oxy-1,4,5,6-tetrahydropyridines, obtained through a CAN-catalyzed four-component reaction, were transformed into highly functionalized pyrido[2,1-b][1,3]oxazepines by ring-closing metathesis (RCM) and ring-closing enyne metathesis (RCEYM) processes, which constitute the first examples of the preparation of 1,3-oxazepine systems using metathesis reactions.