The expedient and regioselective metalation of unprotected biphenyl-2-carboxylic, biphenyl-3-carboxylic, and biphenyl-4-carboxylic acids

被引：36
|
作者：
Tilly, D
Samanta, SS
Castanet, AS
De, A
Mortier, J
机构：
[1] Univ Maine, F-72085 Le Mans 9, France
[2] CNRS, Unite Chim Organ Mol & Macromol, UMR 6011, Fac Sci, F-72085 Le Mans 9, France
[3] Indian Assoc Cultivat Sci, Dept Organ Chem, Kolkata 700032, W Bengal, India
来源：
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY | 2006年 / 2006卷 / 01期
关键词：
ortho-lithiation; unprotected benzoic acids; organolithium compounds; Schlosser-Lochmann superbase; 9H-fluoren-9-one;
D O I：
10.1002/ejoc.200500469
中图分类号：
O62 [有机化学];
学科分类号：
070303 ; 081704 ;
摘要：
Unprotected biphenyl-2-carboxylic acid can be cleanly metalated with sec-butyllithium at the position adjacent to the carboxylate and can then be subjected to site-selective electrophilic substitution. The remote C2'-position is attacked by the superbasic mixture of n-butyllithium and potassium tert-butoxide (LICKOR, 3.5 equiv.) in THF or benzene at 20-60 degrees C. The resulting dianion cyclizes to give the fluorenone skeleton. The metalation reactions of biphenyl-3- and -4-carboxylic acids are also described. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006).
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页码：174 / 182
页数：9
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