Visible-Light-Mediated TiO2-Catalyzed Aerobic Dehydrogenation of N-Heterocycles in Batch and Flow
- Authors
- mincheol, Park
- Issue Date
- 2023-07
- Publisher
- AMER CHEMICAL SOC
- Citation
- 논문 JOURNAL OF ORGANIC CHEMISTRY, v.88, no.15, pp.10682-10692
- Journal Title
- JOURNAL OF ORGANIC CHEMISTRY
- Volume
- 88
- Number
- 15
- Start Page
- 10682
- End Page
- 10692
- ISSN
- 0022-3263
- Abstract
- We report a simple and environmentally friendly methodfor synthesizingN-containing heterocycles via a visible-light-mediated aerobic dehydrogenationreaction. Using a nontoxic, stable, and inexpensive titanium dioxidecatalyst, a variety of substituted quinoline, indole, quinoxaline,and 3,4-dihydroisoquinoline derivatives could be synthesized usingthe green oxidant molecular oxygen. Improved reactivity and scalabilityof this reaction were demonstrated by adapting the photochemical multiphasicreaction to a continuous flow system. To gain insight into the mechanism,we also conducted several mechanistic studies, including absorptionanalysis, light on-off testing, and NMR analysis. Especially,oxygen is reduced to hydrogen peroxide, and dimethyl sulfoxide isa critical scavenger of the oxidant byproduct for ensuring high yields.
