Heterocycles in organic synthesis. Part 18. The replacement of an amino-group by hydrogen via dihydropyridines
Abstract
1-Substituted 2,4,6-triarylpyridinium cations are reduced by sodium borohydride to the corresponding 1,2-dihydropyridines. Whereas the 1-aryl derivatives are thermally stable, 1-benzyl-, 1-allyl-, and 1-heteroarylmethyl-2,4,6-triphenyl-1,2-dihydropyridines afford the corresponding hydrocarbons and triphenylpyridine.