Regiochemical Flexibility: The Optional Functionalization of 2, 3, 5??Trihalopyridines at the 4??or 6??Position

C Bobbio, M Schlosser

Index: Bobbio, Carla; Schlosser, Manfred European Journal of Organic Chemistry, 2001 , # 23 p. 4533 - 4536

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Citation Number: 11

Abstract

Abstract A deprotonation study was performed using 2, 3, 5-trichloropyridine, 3, 5-dichloro-2- fluoropyridine and 5-chloro-2, 3-difluoropyridine as the substrates. Upon reaction with lithium diisopropylamide (LDA), deprotonation occurred exclusively at the 4-position. Subsequent carboxylation and iodination led to the acids 1 and 4-iodopyridines 2. The exposure of the latter compounds to lithium 2, 2, 6, 6-tetramethylpiperidide (LITMP) ...