Addition of novel benzylmagnesium “ate” complexes of BnR₂MgLi type to 2-(thio)pyridones and related compounds

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• 作者：Jacek G. Sośnicki^a ; ^{sosnicki@zut.edu.pl} ; Tomasz Idzik^a ; Aleksandra Borzyszkowska^a ; Emil Wró ; blewski^a ; Gabriela Maciejewska^b ; Łukasz Struk^a
• 关键词：Nucleophilic addition ; Nitrogen heterocycles ; Regioselectivity ; Organomagnesium compounds ; Organolithium compounds
• 刊名：Tetrahedron
• 出版年：2017
• 出版时间：2 February 2017
• 年：2017
• 卷：73
• 期：5
• 页码：481-493
• 全文大小：968 K
• 卷排序：73

文摘

Novel benzylation reagents BnR2MgLi were obtained by mixing benzylmagnesium chloride (BnMgCl) and appropriate organolithium compounds (RLi). As BnR2MgLi complexes are more nucleophilic than the parent Grignard compound they enabled regioselective C6-addition to electrophilic N-substituted 2-(thio)-pyridones and C4-addition to poorly reactive NH 2-(thio)pyridones in high and good yields, respectively. Thus, the application of these new reagents in efficient synthesis of 6-benzyl-3,6-dihydro- and 4-benzyl-3,4-dihydropyridin-2(1H)-ones is described. The prospect of wider application of BnR2MgLi in 1,4-addition to other electrophiles, comprising six-membered α,β-unsaturated systems is also presented.