Fig. 4 |. Pyrimidine to pyridine conversions through deconstruction– reconstruction.

a, Transformations using acetyltrimethylsilane as a nucleophile. b, Pyridine formation using hydrazones or methyl ketones resulting in C5 or C2 substitution. Isolated yields are shown. ^aPyrimidinium salt formation: Tf₂O (1.0 equiv.), aniline (1.0 equiv.), collidine (1.0 equiv.), EtOAc, −78 °C to room temperature. ^bIsolated yields of pyrimidinium salts. Crude vinamidinium salts were used in the recyclization step. ^cIsolated yields of vinamidinium salts either directly from pyrimidines or pyrimidinium salts. LiHMDS, lithium hexamethyldisilazide; LDA, lithium diisopropylamine; THF, tetrahydrofuran.