One-Pot Synthesis of Indolizines Using TBHP as the Methylene Source Under Metal-Free Condition

An I-2/tert-butyl hydroperoxide (TBHP)-mediated [2+1+1+1] cycloadditions/oxidative aromatization reactions for the synthesis of indolizines using the one-pot cascade process have been developed. A variety of aryl methyl ketones react with pyridine/isoquinoline and TBHP in the transition-metal-free reaction. This method utilizes readily available starting materials and TBHP acted in this reaction not only as oxidant and radical initiator but also as a methylene source, therefore providing a novel method of atom economy for the synthesis of indolizines.