TBAI/H2O-cooperative electrocatalytic decarboxylation coupling-annulation of quinoxalin-2(1H)-ones with N-arylglycines

• Published in: Chinese chemical letters 2023-07, Vol.34 (7), p.108036-116, Article 108036
• Main Authors: Lu, Yu-Han, Zhang, Zhuo-Tao, Wu, Hong-Yu, Zhou, Min-Hang, Song, Hai-Yang, Ji, Hong-Tao, Jiang, Jun, Chen, Jin-Yang, He, Wei-Min
• Format: Article
• Language: English
• Subjects: Aminomethyl radical; Annulation reaction; Electrochemistry; Green chemistry
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2022.108036

The first example of TBAI/H2O cooperative electrocatalytic coupling-annulation of quinoxalin-2(1H)-ones with N-arylglycines was developed. A broad range of tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones were obtained in good to excellent yields with exclusive chemoselectivities and excellent regioselectivities. The H-hydrogen bond served as a key factor for the electrocatalytic production of aminomethyl radical at lower oxidative potential. [Display omitted] . The first example of TBAI/H2O cooperative electrocatalytic coupling-annulation of quinoxalin-2(1H)-ones with N-phenylglycines was developed. The reaction proceeds under chemical oxidant-, additive-, exogenous electrolyte-free and mild conditions with high functional-group tolerance, as demonstrated by the acid-, base- and oxidant-sensitive groups can be well tolerated. Mechanistic studies revealed that the generated H-bond between N-arylglycine and water served as a key factor for yielding α-aminomethyl radical at lower oxidative potential.