Chloroacetate Promotes and Participates in the Oxidative Annulation of Pyridines/Isoquinoline by Using Oxygen as the Oxidant

Abstract

The aerobic oxidative annulation of chalcones, pyridines/isoquinoline and ethyl chloroacetate to indolizines was achieved by cascade reaction. Various functional groups on chalcones were tolerated. And different pyridines derivatives could also be suitable substrates. Ethyl chloroacetate is an essential component in participating of the oxidative annulation process. Overall, this protocol is very practical and efficient by using molecular oxygen as oxidant with high selectivity for the annulation product.

Cyclative MCRs of Azines and Azinium Salts

“…[170][171][172] A novel synthetic route towards indolizines (305 and 306) containing electron-withdrawing groups at both the C-1 and C-3 position was developed by Yue and Liu. [173] The reaction is carried out using commercially available chalcones (301), ethyl chloroacetate (302) and isoquinoline/pyridine (303 and 304) in the presence of air oxygen. It was found that not only a wide range of functional groups on chalcones were tolerated, but functionalized pyridine derivatives also.…”