Tetrahedron

Selective substitution of unprotonated phyridines by alkyl radicals

D Chianelli, L Testaferri, M Tiecco, M Tingoli

Index: Chianelli, D.; Testaferri, L.; Tiecco, M.; Tingoli, M. Tetrahedron, 1982 , vol. 38, # 5 p. 657 - 663

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Citation Number: 8

Abstract

The reactions of dioxanyl and cyclohexyl radicals with 2-and 3-X-pyridines (X= CN, COMe, CO2Me) give a single substitution product deriving by addition at the 5-and 6-positions respectively; with 4-X-pyridines substitution occurs preferentially at the 3-position. If the reactions are carried out with protonated pyridines other positional isomers are obtained. From the synthetic point of view the two procedures are therefore complementary. The ...