Synthesis of fluorinated δ-lactams via cycloisomerization of gem-difluoropropargyl amides

gem-Difluoro-1,7-enyne amides are suitable building blocks for the synthesis of difluorodihydropyridinones via a ring-closing metathesis reaction, and of 4,4-difluoro-3-oxoisoquinolines through a ring-closing metathesis-enyne metathesis tandem reaction. These products, in turn, undergo a Diels-Alder reaction to yield heterotricyclic systems in moderate to good yields.