Scope of heterocycle conjugated vinyl methyl ethers^a.

^aReaction conditions: 5 (0.3 mmol), 2 (0.6 mmol), HSiEt₃ (0.9 mmol) and K₃PO₄ (0.45 mmol) were reacted in toluene (1.5 mL) at 110 °C for 24 h under nitrogen atmosphere. Yields were obtained after purification through column chromatography on silica gel.

^bReact for 48 h.