Application of N,N-Dimethylethanolamine as a One-Carbon Synthon for the Synthesis of Pyrrolo[1,2-a]quinoxalines, Quinazolin-4-ones, and Benzo[4,5]imidazoquinazolines via [5+1] Annulation

The synthesis of N-heterocycles composes a significant part of synthetic chemistry. In this report, a Cu(II)-catalyzed green and efficient synthesis of pyrrolo[1,2-a]quinoxaline, quinazolin-4-one, and benzo[4,5]imidazoquinazoline derivatives was developed, employing N,N-dimethylethanolamine (DMEA) as a C1 synthon. Green oxidant O-2 is critical in these transformations, facilitating the formation of a key intermediate-a reactive iminium ion. The method conducted under mild conditions is compatible with a diversity of functional groups, providing an appealing alternative to the previously developed protocols.

Automated summary

This report presents a green and efficient synthesis method for the production of N-heterocycles, specifically pyrrolo[1,2-a]quinoxaline, quinazolin-4-one, and benzo[4,5]imidazoquinazoline derivatives. The method utilizes Cu(II) catalyst and N,N-dimethylethanolamine as a C1 synthon, with the critical inclusion of O-2 as a green oxidant. The method is conducted under mild conditions and is compatible with a variety of functional groups, providing an appealing alternative to previously developed protocols.