Directed lithiation of 4??halopyridines: Chemoselectivity, regioselectivity and application to synthesis

…, F Trécourt, P Bréant, G Quéguiner

文献索引：Marsais, F.; Trecourt, F.; Breant, P.; Queguiner, G. Journal of Heterocyclic Chemistry, 1988 , vol. 25, p. 81 - 87

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被引用次数: 51

摘要

Abstract 4-Chloro and 4-fluoropyridines were ortho-lithiated by n-butyllithium-TMEDA chelate or lithium diiso-propylamide at low temperature. The resulting 3-lithio 4- halopyridines were reacted with electrophiles which led to various 3, 4-disubstituted pyridines. The versatility of this functionalization is enhanced by the 4-halogen reactivity towards nucleophiles such as water, methylate and amines. Some of the 3, 4-disubstituted ...