130543-50-9Relevant academic research and scientific papers
Photoredox-Coupled F-Nucleophilic Addition: Allylation of gem-Difluoroalkenes
Liu, Haidong,Ge, Liang,Wang, Ding-Xing,Chen, Nan,Feng, Chao
, p. 3918 - 3922 (2019/02/19)
A novel strategy for the expedient construction of CF3-embeded tertiary/quarternary carbon centers was developed by taking advantage of photoredox catalysis. Thanks to a key step of single-electron oxidation, electron-rich gem-difluoroalkenes, which otherwise are essentially reluctant towards F-nucleoplilic addition, now readily participate in this fluoroallylation reaction. Furthermore, this strategy provides an elegant example for the generation, as well as functionalization, of α-CF3-substituted benzylic radical intermediates using cheap and readily available starting materials.
Photoredox-Catalyzed Cyclopropanation of 1,1-Disubstituted Alkenes via Radical-Polar Crossover Process
Luo, Wenping,Yang, Yi,Fang, Yewen,Zhang, Xinxin,Jin, Xiaoping,Zhao, Guicai,Zhang, Li,Li, Yan,Zhou, Wanli,Xia, Tingting,Chen, Bin
, p. 4215 - 4221 (2019/08/16)
The photoredox-neutral catalyzed cyclopropanation of 1,1-disubstituted alkenes via radical addition-anionic cyclization cascade has been successfully developed. Another new protocol based on photocatalytic allylation and cyclopropanation cascade was also described between allylic halide and halomethyl radical. In addition to the successful use of bis-catecholato silicates as the alkyl radical precursors, the acyl and alkyl radicals derived from 1,4-dihydropyridines were also engaged in this radical-polar crossover process. The competing experiments displayed that the 3-exo-tet mode of cyclization preferred over 4-exo and 5-exo cyclization modes, allowing for the selective 3-exo-tet cyclization. The superior nucleofuge character of bromide over chloride and tosylate has been demonstrated in the reaction of bromomethyl radical with homoallylic (pseudo)halides. This new protocol is characterized by its redox-neutral process, broad substrate scope, mild conditions, and good functional-group compatibility. (Figure presented.).
Donor–Acceptor Complex Enables Alkoxyl Radical Generation for Metal-Free C(sp3)–C(sp3) Cleavage and Allylation/Alkenylation
Zhang, Jing,Li, Yang,Xu, Ruoyu,Chen, Yiyun
, p. 12619 - 12623 (2017/09/11)
The alkoxyl radical is an essential and prevalent reactive intermediate for chemical and biological studies. Here we report the first donor–acceptor complex-enabled alkoxyl radical generation under metal-free reaction conditions induced by visible light. Hantzsch ester forms the key donor–acceptor complex with N-alkoxyl derivatives, which is elucidated by a series of spectrometry and mechanistic experiments. Selective C(sp3)-C(sp3) bond cleavage and allylation/alkenylation is demonstrated for the first time using this photocatalyst-free approach with linear primary, secondary, and tertiary alkoxyl radicals.
Palladium-Catalyzed Direct Intramolecular C-N Bond Formation: Access to Multisubstituted Dihydropyrroles
Jiang, Bing,Meng, Fei-Fan,Liang, Qiu-Ju,Xu, Yun-He,Loh, Teck-Peng
, p. 914 - 917 (2017/02/26)
A palladium-catalyzed intramolecular amination of alkenes with retention of olefin functionalization was achieved under mild reaction conditions. In the presence of palladium catalyst, the tosyl-protected amine can directly couple with a double bond to provide versatile dihydropyrrole derivatives in moderate to excellent yields.
Generation of Alkoxyl Radicals by Photoredox Catalysis Enables Selective C(sp3)-H Functionalization under Mild Reaction Conditions
Zhang, Jing,Li, Yang,Zhang, Fuyuan,Hu, Chenchen,Chen, Yiyun
, p. 1872 - 1875 (2016/02/03)
Reported herein is the first visible-light-induced formation of alkoxyl radicals from N-alkoxyphthalimides, and the Hantzsch ester as the reductant is crucial for the reaction. The selective hydrogen atom abstraction by the alkoxyl radical enables C(sp3)-H allylation and alkenylation reactions under mild reaction conditions at room temperature. Broad substrate variations, including a structurally complexed steroid, undergo the C(sp3)-H functionalization reaction effectively with high regio- and chemoselectivity.
An expedient and practical approach to functionalized 3-aza-, 3-oxa-, and 3-thiabicyclo[33.1]nonane systems
Ishchenko, Aleksandr Yu.,Yanik, Stanislav,Rusanov, Eduard B.,Komarov, Igor V.,Kirby, Anthony J.
, p. 367 - 376 (2015/02/19)
The synthesis of a number of heterobicyclo[3.3.1]nonane derivatives possessing carbonyl, amino, or carboxyl groups is reported. The synthetic scheme is concise and practical, based on optimized reaction conditions for each step and an orthogonal protection group strategy. Procedures for the key synthetic steps (double annulation of α-bromomethyl acrylates to enamines and a Caglioti reaction) were improved significantly. This makes the compounds attractive for medicinal chemistry as potential chemically diverse 3D-scaffolds applicable in drug design.
An expedient and practical approach to functionalized 3-aza-, 3-oxa-, and 3-thiabicyclo[33.1]nonane systems
Ishchenko, Aleksandr Yu.,Yanik, Stanislav,Rusanov, Eduard B.,Komarov, Igor V.,Kirby, Anthony J.
, (2015/01/16)
The synthesis of a number of heterobicyclo[3.3.1]nonane derivatives possessing carbonyl, amino, or carboxyl groups is reported. The synthetic scheme is concise and practical, based on optimized reaction conditions for each step and an orthogonal protectio
"Flexiball" toolkit: A modular approach to self-assembling capsules
O'Leary,Szabo,Svenstrup,Schalley,Luetzen,Schaefer,Rebek Jr.
, p. 11519 - 11533 (2007/10/03)
We report the synthesis and characterization of new, self-assembling molecular capsules. The modular strategy makes use of glycoluril building blocks available in multigram amounts combined with aromatic spacer elements. The lengthy syntheses encountered with earlier generations of capsules are avoided, and several capsules of nanometer dimensions are now accessible. Single bond attachments between spacers and glycoluril modules result in monomers as dimeric capsules that are less rigid than their earlier counterparts. The host-guest properties of the homo- and heterodimeric capsules were studied using a combination of NMR and ESI-mass spectrometry. They show a less pronounced selectivity for guests of different sizes, and their increased flexibility prevents self-assembly when no rigidifying elements are present on the central spacer unit. Some of the new capsules bear inwardly directed, secondary amide N-H protons. These can be further functionalized, as shown by their methylation to give tertiary analogues. The structures hold broader implications for the placement of functional groups on concave molecular surfaces.
