28353-03-9Relevant articles and documents
The Formation of C-C or C-N Bonds via the Copper-Catalyzed Coupling of Alkylsilyl Peroxides and Organosilicon Compounds: A Route to Perfluoroalkylation
Xu, Weiping,Liu, Yan,Kato, Terumasa,Maruoka, Keiji
, p. 1809 - 1813 (2021)
The copper-catalyzed selective cleavage of alkylsilyl peroxides and the subsequent formation of carbon-carbon or carbon-nitrogen bonds with organosilicon compounds are described. The reaction proceeds under mild conditions and exhibits a broad substrate scope with respect to both cyclic and acyclic alkylsilyl peroxides in combination with carbon and nitrogen sources. In particular, this approach enables the facile radical perfluoroalkylation using commercially available perfluoroalkyltrimethylsilanes. Our mechanistic studies suggest that the reaction should proceed via a free-radical process.
Vinyl Azides as Radical Acceptors in the Vitamin B12-Catalyzed Synthesis of Unsymmetrical Ketones
Dworakowski, Krzysztof R.,Pisarek, Sabina,Hassan, Sidra,Gryko, Dorota
supporting information, p. 9068 - 9072 (2021/11/30)
Vinyl azides are very reactive species and as such are useful building blocks, in particular, in the synthesis of N-heterocycles. They can also serve as precursors of ketones. These form in reactions of vinyl azides with nucleophiles or radicals. We have found, however, that under light irradiation vitamin B12 catalyzes the reaction of vinyl azides with electrophiles to afford unsymmetrical carbonyl compounds in decent yields. Mechanistic studies revealed that alkyl radicals are key intermediates in this transformation.
In-situ-generation of alkylsilyl peroxides from alkyl hydroperoxides and their subsequent copper-catalyzed functionalization with organosilicon compounds
Xu, Weiping,Zhong, Wenfeng,Yang, Qin,Kato, Terumasa,Liu, Yan,Maruoka, Keiji
, (2021/06/16)
Alkylsilyl peroxides were generated in situ from the corresponding alkyl hydroperoxides using organosilicon compounds of the type Me3SiX (X = CN, N3, and halogens) and an amine base. Subsequent in situ copper-catalyzed homolytic cleavage of the alkylsilyl peroxides afforded alkyl radicals, which were then trapped with X (X = CN, N3, and halogens) to furnish products with new carbon-carbon, carbon-nitrogen, or carbon-halogen bonds in good to high yields.
Visible-light-promoted site-specific and diverse functionalization of a c(sp3)-c(sp3) bond adjacent to an arene
Fang, Fang,Liu, Zhong-Quan,Sun, Minzhi,Wang, Nengyong,Wang, Yaxin,You, Huichao,Zhao, Jianyou
, p. 6603 - 6612 (2020/07/27)
We report here a strategy for inert C-C bond functionalization. Site-specific cleavage and functionalization of a saturated C(sp3)-C(sp3) bond via a visible-light-induced radical process have been achieved. The general features of this reaction are as follows. (1) Both linear and cyclic C(sp3)-C(sp3) bonds with a vicinal arene can be specifically functionalized. (2) One carbon is converted into a ketone, and another can be tunably converted into nitrile, peroxide, or halide. (3) The typical conditions include 1.0 mol % of Ru(bpy)3Cl2, 1.0 or 5.0 equiv of Zhdankin reagent, white CFL (24 W), open flask, and room temperature. These reactions offer powerful tools to modify carbon skeletons that are intractable by conventional methods. Good selectivity and functional group tolerance, together with mild and open air conditions, make these transformations valuable and attractive.
Syntheses of Pyrroles, Pyridines, and Ketonitriles via Catalytic Carbopalladation of Dinitriles
Qi, Linjun,Li, Renhao,Yao, Xinrong,Zhen, Qianqian,Ye, Pengqing,Shao, Yinlin,Chen, Jiuxi
, p. 1097 - 1108 (2020/01/22)
The first example of the Pd-catalyzed addition of organoboron reagents to dinitriles, as an efficient means of preparing 2,5-diarylpyrroles and 2,6-diarylpyridines, has been discussed here. Furthermore, the highly selective carbopalladation of dinitriles with organoboron reagents to give long-chain ketonitriles has been developed as well. Based on the broad scope of substrates, excellent functional group tolerance, and use of commercially available substrates, the Pd-catalyzed addition reaction of arylboronic acid and dinitriles is expected to be significant in future synthetic procedures.
Visible light-induced palladium-catalyzed ring opening β-H elimination and addition of cyclobutanone oxime esters
Xing, Wei-Long,Shang, Rui,Wang, Guang-Zu,Fu, Yao
supporting information, p. 14291 - 14294 (2019/12/02)
A palladium catalyst under visible light irradiation activates cyclobutanone oxime ester through single electron transfer to induce radical ring opening to generate hybrid cyanoalkyl Pd(i) radical species. Hybrid cyanoalkyl Pd(i) radical species can undergo either β-H elimination to deliver (E)-4-arylbut-3-enenitrile or undergo radical addition with silyl enol ether and enamide to generate δ-cyano ketones. A dual ligand system composed of two phosphine ligands is essential for the high reactivity.
Radical cyanomethylation via vinyl azide cascade-fragmentation
Donald, James R.,Berrell, Sophie L.
, p. 5832 - 5836 (2019/06/17)
Herein, a novel methodology for radical cyanomethylation is described. The process is initiated by radical addition to the vinyl azide reagent 3-azido-2-methylbut-3-en-2-ol which triggers a cascade-fragmentation mechanism driven by the loss of dinitrogen and the stabilised 2-hydroxypropyl radical, ultimately effecting cyanomethylation. Cyanomethyl groups can be efficiently introduced into a range of substrates via trapping of α-carbonyl, heterobenzylic, alkyl, sulfonyl and aryl radicals, generated from a variety of functional groups under both photoredox catalysis and non-catalytic conditions. The value of this approach is exemplified by the late-stage cyanomethylation of pharmaceuticals.
Photoinduced C—C Bond Cleavage and Oxidation of Cycloketoxime Esters
Zhao, Binlin,Tan, Hui,Chen, Cheng,Jiao, Ning,Shi, Zhuangzhi
, p. 995 - 999 (2018/09/25)
A novel structural reorganization of cycloketoxime esters beyond the traditional Beckmann rearrangement process has been established to build cyano-containing ketones in the presence of photocatalyst. This novel transformation is remarkable with selective C—C bond cleavage and an oxidation process enabled by DMSO used as the solvent, oxidant, and oxygen source avoiding acid, base and toxic cyanide salts as the cyano source. Further applications in late-stage modification of complex and chiral molecules have also been reported.
A photoredox catalyzed iminyl radical-triggered C-C bond cleavage/addition/Kornblum oxidation cascade of oxime esters and styrenes: synthesis of ketonitriles
He, Bin-Qing,Yu, Xiao-Ye,Wang, Peng-Zi,Chen, Jia-Rong,Xiao, Wen-Jing
supporting information, p. 12262 - 12265 (2018/11/21)
A photoredox-catalyzed iminyl radical-triggered C-C bond cleavage/addition/Kornblum oxidation cascade of cycloketone oxime esters and styrenes in DMSO is described. This three-component, one-pot procedure features mild conditions, a broad substrate scope, and high functional group tolerance, providing an efficient approach to access diversely functionalized ketonitriles.
A Visible-Light-Driven Iminyl Radical-Mediated C?C Single Bond Cleavage/Radical Addition Cascade of Oxime Esters
Yu, Xiao-Ye,Chen, Jia-Rong,Wang, Peng-Zi,Yang, Meng-Nan,Liang, Dong,Xiao, Wen-Jing
supporting information, p. 738 - 743 (2017/12/26)
A room-temperature, visible-light-driven N-centered iminyl radical-mediated and redox-neutral C?C single bond cleavage/radical addition cascade reaction of oxime esters and unsaturated systems has been accomplished. The strategy tolerates a wide range of O-acyl oximes and unsaturated systems, such as alkenes, silyl enol ethers, alkynes, and isonitrile, enabling highly selective formation of various chemical bonds. This method thus provides an efficient approach to various diversely substituted cyano-containing alkenes, ketones, carbocycles, and heterocycles.
