Title:Using the Sonogashira Reaction for Preparing a New Fragment Library based on the 3-alkynylimidazo[1,2-a]pyridine Scaffold
Volume: 13
Issue: 7
Author(s): Caroline Castera-Ducros, Hussein El-Kashef, Melanie Piednoel, Vincent Remusat, Jean-Claude Teulade, Pierre Verhaeghe, Pascal Rathelot and Patrice Vanelle
Affiliation:
Keywords:
3-halogenoimidazo[1, 2-a]pyridines, Sonogashira cross-coupling reaction, 3-alkynylimidazoimidazo[1, 2-a]pyridine.
Abstract: Background: The imidazo[1,2-a]pyridine ring has been widely studied by medicinal chemists
and displays great pharmaceutical potential.
Methods: In a view to prepare a library of new molecules including an imidazo[1,2-a]pyridine scaffold,
as original fragments for the conception of novel anti-protozoal compounds, the Sonogashira crosscoupling
reaction between 3-halogenoimidazo [1,2-a]pyridines and phenylacetylene was studied.
Results: From 3-iodoimidazo[1,2-a]pyridine, chosen as an optimal substrate for conducting the reaction
at room temperature in 2 hours, a variety of terminal alkynes was involved into the reaction, leading to a
series of 16 new 3-phenyethynylimidazo [1,2-a]pyridines in satisfying to good yields (50-82%) and 4 additional
derivatives in moderate yields (30-40%).
Conclusion: Such synthetic approach appears efficient for the rapid synthesis of imidazopyridine chemical
libraries. The corresponding derivatives will next be evaluated for their anti-infective properties.
