First metalation of aryl iodides: directed ortho-lithiation of iodopyridines, halogen-dance, and application to synthesis

…, F Marsais, L Thomas-dit-Dumont…

Index: Rocca, P.; Cochennec, C.; Marsais, F.; Thomas-dit-Dumont, L.; Mallet, M.; et al. Journal of Organic Chemistry, 1993 , vol. 58, # 27 p. 7832 - 7838

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Citation Number: 137

Abstract

Results (I) Metalation of 2-Halo-34odopyridines (Chloro and Fluoro). 2-Fluoro-and 2-chloro- 34odopyridines (1 and 2) were readily prepared from the corresponding 2-halopyridines by a metalation-iodination sequence. 14 Treatment of these iodopyridines 1 and 2 with LDA at- 75" C followed by quenching with electrophiles led to the 3-substituted 2-halo-4- iodopyridines 7a-g and 8a-g in good to high yields (Scheme I, Table I). Identification of ...