2475-90-3Relevant academic research and scientific papers
Photoinduced Copper-Catalyzed Asymmetric C-O Cross-Coupling
Chen, Jun,Liang, Yu-Jie,Wang, Peng-Zi,Li, Guo-Qing,Zhang, Bin,Qian, Hao,Huan, Xiao-Die,Guan, Wei,Xiao, Wen-Jing,Chen, Jia-Rong
supporting information, p. 13382 - 13392 (2021/09/03)
The construction of carbon-heteroatom bonds is one of the most active areas of research in organic chemistry because the function of organic molecules is often derived from the presence of heteroatoms. Although considerable advances have recently been achieved in radical-involved catalytic asymmetric C-N bond formation, there has been little progress in the corresponding C-O bond-forming processes. Here, we describe a photoinduced copper-catalyzed cross-coupling of readily available oxime esters and 1,3-dienes to generate diversely substituted allylic esters with high regio- and enantioselectivity (>75 examples; up to 95% ee). The reaction proceeds at room temperature under excitation by purple light-emitting diodes (LEDs) and features the use of a single, earth-abundant copper-based chiral catalyst as both the photoredox catalyst for radical generation and the source of asymmetric induction in C-O coupling. Combined experimental and density functional theory (DFT) computational studies suggest the formation of π-allylcopper complexes from redox-active oxime esters as bifunctional reagents and 1,3-dienes through a radical-polar crossover process.
Directed Cobalt-Catalyzed anti-Markovnikov Hydroalkylation of Unactivated Alkenes Enabled by "co-H" Catalysis
Yang, Dandan,Huang, Hai,Li, Meng-Hui,Si, Xiao-Ju,Zhang, He,Niu, Jun-Long,Song, Mao-Ping
supporting information, p. 4333 - 4338 (2020/06/04)
The earth-abundant cobalt-catalyzed anti-Markovnikov hydroalkylation of unactivated alkenes with oxime esters was achieved by introducing an 8-aminoquinoline directing group on the alkenes. The catalytic system, consisting of commercially available Co(acac)3 and PhMeSiH2, enables the construction of unfunctionalized C(sp3)-C(sp3) bonds and features exclusive anti-Markovnikov selectivity, good functional group tolerance, and the avoidance of an extra ligand, oxidant, or base. Mechanistic insight into this new catalytic system indicates the involvement of both alkyl radical and cobalt hydride intermediates.
Photoinduced, Copper-Catalyzed Radical Cross-Coupling of Cycloketone Oxime Esters, Alkenes, and Terminal Alkynes
Chen, Jun,He, Bin-Qing,Wang, Peng-Zi,Yu, Xiao-Ye,Zhao, Quan-Qing,Chen, Jia-Rong,Xiao, Wen-Jing
supporting information, p. 4359 - 4364 (2019/06/08)
A photoinduced, copper-catalyzed three-component radical cross-coupling of cycloketone oxime esters, alkenes, and terminal alkynes is described for the first time. Key to the success of this process was the integration of photoinduced iminyl radical-mediated C-C bond cleavage with the conceptual simplicity of copper-catalyzed radical cross-coupling. This protocol provides access to cyanoalkyl-containing propargylic compounds in good yields.
Copper-Catalyzed Intermolecular Heck-Like Coupling of Cyclobutanone Oximes Initiated by Selective C?C Bond Cleavage
Zhao, Binlin,Shi, Zhuangzhi
supporting information, p. 12727 - 12731 (2017/09/08)
The first example of intermolecular olefination of cyclobutanone oximes with alkenes via selective C?C bond cleavage leading to the synthesis of nitriles in the presence of a cheap copper catalyst is reported. The procedure is distinguished by mild and safe reaction conditions that avoid ligand, oxidant, base, or toxic cyanide salt. A wide scope of cyclobutanones and olefin coupling components can be used without compromising efficiency and scalability. The alternative visible-light-driven photoredox process for this coupling reaction was also uncovered.
Discovery of aryloxy tetramethylcyclobutanes as novel androgen receptor antagonists
Guo, Chuangxing,Linton, Angelica,Kephart, Susan,Ornelas, Martha,Pairish, Mason,Gonzalez, Javier,Greasley, Samantha,Nagata, Asako,Burke, Benjamin J.,Edwards, Martin,Hosea, Natilie,Kang, Ping,Hu, Wenyue,Engebretsen, Jon,Briere, David,Shi, Manli,Gukasyan, Hovik,Richardson, Paul,Dack, Kevin,Underwood, Toby,Johnson, Patrick,Morell, Andrew,Felstead, Robert,Kuruma, Hidetoshi,Matsimoto, Hiroaki,Zoubeidi, Amina,Gleave, Martin,Los, Gerrit,Fanjul, Andrea N.
supporting information; experimental part, p. 7693 - 7704 (2011/12/22)
An aryloxy tetramethylcyclobutane was identified as a novel template for androgen receptor (AR) antagonists via cell-based high-throughput screening. Follow-up to the initial "hit" established 5 as a viable lead. Further optimization to achieve full AR antagonism led to the discovery of 26 and 30, both of which demonstrated excellent in vivo tumor growth inhibition upon oral administration in a castration-resistant prostate cancer (CRPC) animal model.
Imines and Derivatives. Part 21. A Study of Structural and Mechanistic Aspects of the Synthesis of Imine, Imine Oxide, and Oxime Derivatives of 2,2,4,4-Tetramethylcyclobutane-1,3-Dione by X-Ray Crystalography and Nuclear Magnetic Resonance and Ultraviolet Spectroscopy
Boyd, A. John,Boyd, Derek R.,Burnett, Michael G.,Malone, John F.,Jennings, W. Brian
, p. 2093 - 2098 (2007/10/02)
The dinitrone derivatives (5a, b) of 2,2,4,4-tetramethylcyclobutane-1,3-dione were synthesised by peroxyacid oxidation of the corresponding di-imines (3a, b).X-ray crystallographic analysis of diimine (3a) and the hydroxyimino nitrone isomers (6a, b) indicate a marked buttressing effect leading to an exclusive preference for the trans geometry in di-imine (3a) and dinitrone (5a).Thermal elimination reactions of the N-But substituted nitrones (5a), (6a), and (8a) to yield oximes and 2-methylpropene have been investigated bu u.v. kinetic studies.The results areconsistent with a concerted mechanism involving a five-membered cyclic transition state.
