| ชื่อเรื่อง | : | Selective bromination of sp3 C-H bonds by organophotoredox catalysis |
| นักวิจัย | : | Kee, Choon Wee , Chan, Ke Min , Wong, Ming Wah , Tan, Choon-Hong |
| คำค้น | : | DRNTU::Science::Chemistry::Organic chemistry |
| หน่วยงาน | : | Nanyang Technological University, Singapore |
| ผู้ร่วมงาน | : | - |
| ปีพิมพ์ | : | 2557 |
| อ้างอิง | : | Kee, C. W., Chan, K. M., Wong, M. W., & Tan, C.-H. (2014). Selective Bromination of sp3 C-H Bonds by Organophotoredox Catalysis . Asian Journal of Organic Chemistry, 3(4), 536-544. , 2193-5807 , http://hdl.handle.net/10220/19712 , http://dx.doi.org/10.1002/ajoc.201300169 |
| ที่มา | : | - |
| ความเชี่ยวชาญ | : | - |
| ความสัมพันธ์ | : | Asian journal of organic chemistry |
| ขอบเขตของเนื้อหา | : | - |
| บทคัดย่อ/คำอธิบาย | : | We report that bromination of aliphatic and benzylic sp3 C[BOND]H bonds can be achieved with visible light photoredox catalysis by using a low loading of Eosin Y disodium salt, an inexpensive organic dye, as a photoredox catalyst. The light source is a low-power household lamp and the reaction can be performed without the need of an inert atmosphere and anhydrous solvent. Easy-to-handle CBr4 is the source of bromine and morpholine is necessary for the reaction. Preliminary experimental and computational studies on the mechanism strongly suggest that an N-morpholino radical is responsible for the C[BOND]H activation step. This led us to propose that this is a radical relay reaction, in which a longer-lived morpholine radical is generated from a CBr3 radical, which is relatively more transient, by a thermodynamically favorable reaction. Additional evidence for the existence of such an N-radical was obtained from radical trapping experiments. The strong preference of this reaction for electron-rich hydrogen atoms, and the high sensitivity to the steric environment around the C[BOND]H bond enables bromination to occur on the relatively stronger C[BOND]H bond (as quantified by bond dissociation enthalpy) on the same molecule. The potential for utilizing this reaction to achieve mild and regioselective bromination of sp3 C[BOND]H bonds in complex molecules is exemplified by the bromination of (+)-sclareolide and acetate-protected estrone. |
| บรรณานุกรม | : |
Kee, Choon Wee , Chan, Ke Min , Wong, Ming Wah , Tan, Choon-Hong . (2557). Selective bromination of sp3 C-H bonds by organophotoredox catalysis.
กรุงเทพมหานคร : Nanyang Technological University, Singapore. Kee, Choon Wee , Chan, Ke Min , Wong, Ming Wah , Tan, Choon-Hong . 2557. "Selective bromination of sp3 C-H bonds by organophotoredox catalysis".
กรุงเทพมหานคร : Nanyang Technological University, Singapore. Kee, Choon Wee , Chan, Ke Min , Wong, Ming Wah , Tan, Choon-Hong . "Selective bromination of sp3 C-H bonds by organophotoredox catalysis."
กรุงเทพมหานคร : Nanyang Technological University, Singapore, 2557. Print. Kee, Choon Wee , Chan, Ke Min , Wong, Ming Wah , Tan, Choon-Hong . Selective bromination of sp3 C-H bonds by organophotoredox catalysis. กรุงเทพมหานคร : Nanyang Technological University, Singapore; 2557.
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