Visible-light-induced aerobic C3-H fluoroalkoxylation of quinoxalin-2(1 H )-ones with fluoroalkyl alcohols.

A novel and efficient method of visible-light-induced C3-H fluoroalkoxylation of quinoxalin-2(1 H )-ones with fluoroalkyl alcohols is developed. This approach uses readily available fluoroalkyl alcohols as fluoroalkoxylation reagents and displays a wide substrate scope, providing the fluoroalkoxylated products in moderate to good yields. Compared with the previous method, such a transformation uses oxygen as an oxidant, which avoids the utilization of plenty of PhI(TFA) 2 . In addition, this strategy also gives a practical tool for the rapid synthesis of histamine-4 receptor antagonist and new N-containing bidentate ligands. A radical mechanism was suggested according to the results of control experiments.