Formation of Benzynes from 2,6-Dihaloaryllithiums: Mechanistic Basis of the Regioselectivity

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• 作者：Antonio Ramí ; rez ; John Candler ; Crystal G. Bashore ; Michael C. Wirtz ; Jotham W. Coe ; and David B. Collum
• 刊名：Journal of the American Chemical Society
• 出版年：2004
• 出版时间：November 17, 2004
• 年：2004
• 卷：126
• 期：45
• 页码：14700 - 14701
• 全文大小：49K
• 年卷期：v.126,no.45(November 17, 2004)
• ISSN：1520-5126

文摘

The key elimination step for the formation of 3-chloro- and 3-fluorobenzyne from 2-chloro-6-fluorophenyllithium displays a pronounced solvent-dependent regioselectivity. ⁶Li and ¹³C NMR spectroscopic studies on 2-chloro-6-fluorophenyllithium reveal a single monomeric aryllithium, suggested by DFT computational studies to be a trisolvate. Rate studies indicate that the elimination of LiCl and LiF proceeds via trisolvated and disolvated monomers, respectively.