Details

Autor(en) / Beteiligte

• Liu, Qiang
• Li, Ya-Nan
• Zhang, Hui-Hui
• Chen, Bin
• Tung, Chen-Ho
• Wu, Li-Zhu

Titel

Reactivity and Mechanistic Insight into Visible-Light-Induced Aerobic Cross-Dehydrogenative Coupling Reaction by Organophotocatalysts

Ist Teil von

• Chemistry : a European journal, 2012-01, Vol.18 (2), p.620-627

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2012

Quelle

Wiley Online Library

Beschreibungen/Notizen

• With visible‐light irradiation, a mild, simple, and efficient metal‐free photocatalytic system for the facile construction of sp3–sp3 CC bonds between tertiary amines and activated CH bonds has been achieved. Spectroscopic study and product analysis demonstrate for the first time that photoinduced electron transfer from N‐aryl tetrahydroisoquinolines to eosin Y bis(tetrabutylammonium salt) (TBA‐eosin Y) takes place to generate TBA‐eosin Y radical anion, which can subsequently react with nucleophiles and molecular oxygen. More strikingly, electron spin resonance (ESR) measurements provide direct evidence for the formation of superoxide radical anions (O2−.) rather than singlet oxygen (1O2) during visible‐light irradiation. This active species is therefore believed to be responsible for the large rate of acceleration of the aerobic photocatalytic reactions. Light work: With visible‐light irradiation (λ>450 nm), a mild, simple and efficient metal‐free photocatalytic system for the facile construction of sp3–sp3 CC bonds between tertiary amines and activated CH bonds has been achieved (see scheme). Electron spin resonance measurements offer direct evidence for the formation of superoxide radical anions (O2−.) during visible‐light irradiation.