A Practical Approach to Regioselective C3 Selenylation of Indolizines

Indolizine (pyrrolo[1,2-a]pyridine) is an isomer of indole. The diversity of synthetic approaches available for the construction of the indolizine skeleton is unparalleled among heterocycles of comparable size. The direct introduction of selenium into heteroaromatic scaffolds represents an attractive strategy for accessing organoselenium compounds with enhanced biological potential. Herein, we report a CuI-catalyzed, regioselective C3 selenylation of indolizine derivatives using diselenides as the selenium source and m-chloroperbenzoic acid (mCPBA) as the oxidant. The developed methodology provides efficient access to selenium-functionalized indolizines under mild reaction conditions with excellent regioselectivity for the C3 position.