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Published on: July 28, 2022
Regioselective C2-arylation of imidazo[4,5-b]pyridines
Jonathan Macdonald1, Victoria Oldfield, Vassilios Bavetsias
1Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, Sutton, Surrey SM2 5NG, UK.
Abstract:
We show that N3-MEM-protected imidazo[4,5-b]pyridines undergo efficient C2-functionalisation via direct C-H arylation. Twenty-two substituted imidazo[4,5-b]pyridines are prepared and iterative, selective elaboration of functionalised imidazo[4,5-b]pyridines gives 2,7- and 2,6-disubstituted derivatives in good yields from common intermediates. Mechanistic observations are consistent with a concerted-metallation-deprotonation mechanism facilitated by coordination of copper(I)iodide to the imidazo[4,5-b]pyridine.
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