Long‐Lived Excited States of Zwitterionic Copper(I) Complexes for Photoinduced Cross‐Dehydrogenative Coupling Reactions |
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| Authors: | Dr. Bin Wang Dr. Deepak Prakash Shelar Xian‐Zhu Han Ting‐Ting Li Dr. Xiangguo Guan Prof. Dr. Wei Lu Dr. Kun Liu Prof. Dr. Yong Chen Prof. Dr. Wen‐Fu Fu Prof. Dr. Chi‐Ming Che |
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| Affiliation: | 1. Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Key Laboratory of Inorganic‐Organic Hybrid Functional Materials Chemistry, Ministry of Education, College of Chemistry, Tianjin Normal University, Tianjin 300387 (China);2. Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China), Fax: (+86)?10‐6255‐4670;3. State Key Laboratory of Synthetic Chemistry, HKU‐CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (China);4. Department of Chemistry, South University of Science and Technology of China, Shenzhen, Guangdong 518055 (China) |
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| Abstract: | Four heteroleptic copper(I) complexes containing phenanthroline and monoanionic nido‐carborane‐diphosphine ligands have been prepared and structurally characterized by various spectroscopic techniques and X‐ray diffraction. These complexes exhibit intense absorptions in the visible range and excited‐state lifetimes on the microsecond scale. Their application in visible‐light‐induced cross‐dehydrogenative coupling reactions was investigated. Preliminary studies showed that one of the four copper(I) complexes is an efficient catalyst for photoinduced oxidative C?H functionalization using oxygen as oxidant. Furthermore, α‐functionalized tertiary amines were obtained in good‐to‐excellent yields by light irradiation (λ>420 nm) of a mixture of our CuI complex, tertiary amines, and a variety of nucleophiles (nitroalkane, acetone, or indoles) under aerobic conditions. Electron paramagnetic resonance measurements provided evidence for the formation of superoxide radical anions (O2??) rather than singlet oxygen (1O2) during these photocatalytic reactions. |
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| Keywords: | carboranes copper cross‐coupling photocatalysis UV/Vis spectroscopy |
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