A new synthetic approach to 6,7-disubstituted indolizines has been developed from pyrrole-2-carboxaldehydes and allyl bromides via two successive base-mediated reactions. As three-carbon units for formation of pyridine moiety of indolizines, allyl bromides easily derived from Morita-Baylis-Hillman (MBH) adducts were employed. We found that positioning electron-withdrawing group(s) at the aromatic ring of allyl bromides was a key to successful ring closure to allow access to indolizines with unique substitution style. Structurally relevant imidazo[1,2-a]pyridine and pyrido[1,2-a]indole were assembled by this method as well.
Bibliographical noteFunding Information:
This research was supported in part by Nano·Material Technology Development Program through the National Research Foundation of Korea (NRF) funded by the Korean Ministry of Education, Science and Technology . This work was also supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) ( 2014R1A2A1A11050491 ).
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All Science Journal Classification (ASJC) codes
- Drug Discovery
- Organic Chemistry