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Pyridines

Aldrich ChemFiles 2006, 6.6, 9.

Aldrich ChemFiles 2006, 6.6, 9.

Pyridines have been of interest to scientists across a number of disciplines. The pyridine moiety is presented in countless molecules with applications as varied as catalysis, drug design, molecular recognition, and natural product synthesis.

Recently, Blackaby and co-workers reacted a series of different pyridines with a common imidazo[1,2-a]pyrimidine core to create functionally selective GABAA ligands (Scheme 16).1 Another report described the use of 2-chloropyridines in the regioselective preparation of pyridin-2-yl ureas (Scheme 17).2

Scheme 16

Scheme 17

Schlosser has recently reported a method to reverse the selectivity of nucleophilic substitution on 2,4-substituted di-, tri-, and tetrahalopyridines by introducing a trialkylsilyl group in the 3- or 5-position. The bulky silyl group sterically blocks the 4-position, forcing substitution at the 2- or 6-position (Scheme 18).3

Scheme 18

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Materials

     

References

  1. Blackaby, W. P. et al. Bioorg. Med. Chem. Lett. 2006, 16, 1175.
  2. Abad, A. et al. Synthesis 2005, 915.
  3. (a) Schlosser, M. et al. J. Org. Chem. 2005, 70, 2494. (b) Schlosser, M. et al. Org. Lett. 2005, 7, 127.

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