In this HOT paper, Blagg and coworkers at the Institute of Cancer Research, Sutton, report an efficient C2-functionalisation via direct C–H arylation for N3-MEM-protected imidazo[4,5-b]pyridines. The imidazo[4,5-b]pyridine heterocycle is a versatile purine isostere and important ring system which has seen a recent growth in medicinal chemistry application of potential therapeutic benefit; for example in protein kinase inhibitors for the treatment of cancer, inflammatory disease and diabetes. This methodology allows easy access to 2,7- and 2,6-disubstituted derivatives from common intermediates in an approach amenable to the divergent synthesis of analogues and which is applicable to rapid medicinal chemistry exploration of this emerging purine isostere.
![Direct C2-H arylation of 6- and 7-substituted imidazo[4,5-b]pyridines](https://blogs.rsc.org/ob/files/2013/03/GA4.gif "Direct arylation of substituted imidazo[4,5-b]pyridines")
Regioselective C2-arylation of imidazo[4,5-b]pyridines
Jonathan Macdonald, Victoria Oldfield, Vassilios Bavetsias and Julian Blagg
DOI: 10.1039/C3OB27477B
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