Table 3.

Scope of Pyridine Building Blocks, Drug-Like Fragments, and Complex Bioactive Molecules^a,b

^aTypical salt-forming conditions: azine (1.0 equiv), Tf₂O (1.0 equiv), PPh₃ (1.1 equiv), DBU (1.1 equiv) CH₂Cl₂ or EtOAc, −78 °C to rt.

^bIsolated yields of products as single regioisomers (unless stated) are shown with yields of phosphonium salts in parentheses.

^cThe reaction was conducted at 50 °C.

^dA 3.5:1 mixture of 2u and 2,4-dicyclobutylpyridine was observed in the crude ¹H NMR spectrum.