通过使用铁催化的CF胺,可以从二芳基胺一锅合成各种5,10-diaryl-5,10-dihydrophenazines(DADHPs)。在催化FeCl 2和化学计量的1,2-二溴乙烷存在下,二芳基酰胺镁的均二聚化,然后进行脱氟分子内环化(双邻位CF胺化),可提供相应的DADHPs,具有完全的区域控制能力。氟对其他卤素的独特高反应性表明,胺化是通过铁促进的S N Ar机理进行的。
COMPOSITIONS AND METHODS OF PROMOTING ORGANIC PHOTOCATALYSIS
申请人:THE REGENTS OF THE UNIVERSITY OF COLORADO, A BODY CORPORATE
公开号:US20180237550A1
公开(公告)日:2018-08-23
The invention provides novel compounds and methods that are useful in promoting reactions that proceed through an oxidative quenching pathway. In certain embodiments, the reactions comprise atom transfer radical polymerization.
Phenazine radicalcations (PhRCs) were used for the first time as efficient metal-free catalysts for the oxidative homo- and cross-coupling of a variety of different amines. A series of functional PhRCs were prepared, characterized with X-ray diffraction, and their radical character was investigated with DFT calculations. They were tested as catalysts under neat conditions with low oxygen pressure
Radical Cations of Phenoxazine and Dihydrophenazine Photoredox Catalysts and Their Role as Deactivators in Organocatalyzed Atom Transfer Radical Polymerization
作者:Daniel A. Corbin、Blaine G. McCarthy、Zach van de Lindt、Garret M. Miyake
DOI:10.1021/acs.macromol.1c00640
日期:2021.5.25
deactivate alkyl radicals. A number of other factors that could influence deactivation in O-ATRP were also probed, such as ion pairing with the radical cations, radical cation oxidation potential, and halide oxidation potential. Ultimately, these studies enabled radical cations to be employed as reagents during O-ATRP to demonstrate improvements in polymerizationcontrol with increasing radical cation concentrations
Ultrafast Observation of a Photoredox Reaction Mechanism: Photoinitiation in Organocatalyzed Atom-Transfer Radical Polymerization
作者:Daisuke Koyama、Harvey J. A. Dale、Andrew J. Orr-Ewing
DOI:10.1021/jacs.7b07829
日期:2018.1.31
ground state, and radical cation are tracked in real time alongside the debrominated radical fragment. Our work challenges previously proposed mechanisms of initiation in O-ATRP and indicates that PET from short-lived excited singlet states can exert control of polymer molecular weight and dispersity by suppressing the steady-state concentration of the reactive debrominated radical. More broadly, we
光氧化还原催化推动了有机化学领域的一场革命,但对真正合成效用的反应的直接机制洞察仍然相对稀缺。在这里,我们报告了双分子有机催化光氧化还原反应的超快时间分辨光谱观察,从催化剂光激发到光诱导电子转移 (PET) 和中间体形成,使用具有亚皮秒时间分辨率的瞬态振动和电子吸收光谱。具体而言,阐明了两种互补的光氧化还原有机催化剂(N,N-二芳基-5,10-二氢吩嗪)在有机催化原子转移自由基聚合(O-ATRP)中引发的光化学动力学。光激发后,在二氯甲烷、甲苯和二甲基甲酰胺中,观察到从两种光催化剂的第一激发单线态到 2-溴丙酸甲酯的解离双分子电子转移。光催化剂激发的供体态、基态和自由基阳离子与脱溴自由基片段一起实时跟踪。我们的工作挑战了先前提出的 O-ATRP 引发机制,并表明来自短寿命激发单线态的 PET 可以通过抑制反应性脱溴自由基的稳态浓度来控制聚合物的分子量和分散性。更广泛地说,我们旨在证明超快吸
Redox‐Induced Modulation of Exchange Interaction in a High‐Spin Ground‐State Diradical/Triradical System
temperature-dependent magnetic susceptibilities reveal that 1.. and 1…+ are in the triplet state, with a weak exchange interaction (J1 /kB = +3.1 K) and quartet ground state with a strong exchange interaction (J2 /kB = +160 K), respectively. The interconversion between the neutral and one-electron oxidized species can be realized through electrochemical reactions. Significantly different absorption bands in the