Arene-metal complex in organic synthesis: directed regioselective lithiation of (. pi.-substituted benzene) chromium tricarbonyl complexes

M Uemura, N Nishikawa, K Take…

Index: Uemura, Motokazu; Nishikawa, Naomi; Take, Kazuhiko; Ohnishi, Masato; Hirotsu, Ken; et al. Journal of Organic Chemistry, 1983 , vol. 48, # 14 p. 2349 - 2356

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Citation Number: 46

Abstract

(3-Methoxybenzyl alcoho1) chromium tricarbonyl complex (8) and (2-substituted 7-methoxy- 1-tetralo1) chromium complexes 14-17 are selectively lithiated at the 4-position and 6- position, respectively, by treatment with n-BuLilTMEDA. The regioselectivity of this lithiation is improved with increasing bulk of the butyllithium reagent employed. Since the direct lithiation of the corresponding chromium-free arenes normally proceeds at the 2-and 8- ...