Long??Range Effects in the Metalation/Boronation of Functionalized 1, 4??Dihalobenzenes

…, J Serwatowski, A Zaczek

Index: Lulinski, Sergiusz; Serwatowski, Janusz; Zaczek, Anna European Journal of Organic Chemistry, 2006 , # 22 p. 5167 - 5173

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Citation Number: 5

Abstract

Abstract The lithiation/boronation of 1, 4-dihalobenzenes (Hal= F, Cl, Br) bearing various functional groups in the 2-position was investigated using lithium diisopropylamide (LDA) as the metalating agent and trialkyl borate B (OR) 3 (R= Et, iPr) as the electrophile. It was demonstrated that sufficient steric hindrance precludes effective ortho-lithiation at the 3- position. In such cases, a strong meta-directing effect of an oxygen-or sulfur-based ...