55991-65-6Relevant academic research and scientific papers
β-Diazocarbonyl Compounds: Synthesis and their Rh(II)-Catalyzed 1,3 C?H Insertions
Jiang, Liyin,Wang, Zhaofeng,Armstrong, Melanie,Suero, Marcos G.
supporting information, p. 6177 - 6184 (2021/02/01)
Herein, we describe the first electrophilic diazomethylation of ketone silyl enol ethers with diazomethyl-substituted hypervalent iodine reagents that gives access to unusual β-diazocarbonyl compounds. The potential of this unexplored class of diazo compounds for the development of new reactions was demonstrated by the discovery of a rare Rh-catalyzed intramolecular 1,3 C?H carbene insertion that led to complex cyclopropanes with excellent stereocontrol.
Versatile and base-free copper-catalyzed α-arylations of aromatic ketones using diaryliodonium salts
Bouquin, Maxime,Jaroschik, Florian,Taillefer, Marc
supporting information, (2021/06/11)
A ligand and base-free copper catalyzed synthetic method for the efficient α-arylation of aromatic ketones is described. In order to avoid strong bases, ketone-derived silyl enol ethers were employed. Their reaction with diaryliodonium salts as aryl source provided the intermolecular C–C coupling displaying good functional group tolerance and requiring low catalyst loading.
Iron-Catalyzed Ring-Opening Reactions of Cyclopropanols with Alkenes and TBHP: Synthesis of 5-Oxo Peroxides
Lou, Chenhao,Wang, Xin,Lv, Leiyang,Li, Zhiping
supporting information, p. 7608 - 7612 (2021/10/02)
The ring opening of cyclopropanols is rarely used in multicomponent reactions. Herein we report the three-component reaction of cyclopropanols with alkenes and tert-butyl hydroperoxide (TBHP) catalyzed by an iron catalyst. This protocol enables the incorporation of both the β-carbonyl fragment and a peroxy unit across the C=C double bond regioselectively, thus allowing an efficient, facile access to 5-oxo peroxides. Modification of the biologically active molecules and various downstream derivatizations of the peroxides are also demonstrated.
Three-Component Coupling of Acyl Fluorides, Silyl Enol Ethers, and Alkynes by P(III)/P(V) Catalysis
Fujimoto, Hayato,Kusano, Momoka,Kodama, Takuya,Tobisu, Mamoru
supporting information, p. 18394 - 18399 (2021/11/22)
We report herein on the phosphine-catalyzed hydrovinylation reaction by three-component coupling of acyl fluorides, silyl enol ethers, and alkynoates. The key to the success of the reaction is the formal transmetalation between pentacoordinate P(V) species (i.e., fluorophosphorane) and a silyl enol ether, which allows for C-C bond formation between the polarity-mismatched sites. The bond formation that cannot be attained even by transition metal catalysis is accomplished by a P(III)/P(V) manifold.
Photoinduced Deaminative Alkylation for the Synthesis of γ-Ketoesters via Electron Donor–Acceptor Complex Formation
Wang, Jia-Xin,Ge, Wei,Xing, Wei-Long,Fu, Ming-Chen
supporting information, p. 18224 - 18231 (2021/12/13)
Visible-light-induced deaminative alkylation of Katritzky salts with silyl enol ethers has been developed. The reaction can proceed efficiently through electron donor–acceptor complex formation, avoiding the use of precious metal complexes or synthetically elaborate organic dyes. A series of functionalized γ-ketoesters was successfully obtained with good functional group tolerance and compatibility under mild and straightforward conditions.
σ-Bond initiated generation of aryl radicals from aryl diazonium salts
Chan, Bun,McErlean, Christopher S. P.,Nashar, Philippe E.,Tatunashvili, Elene
supporting information, p. 1812 - 1819 (2020/03/17)
σ-Bond nucleophiles and molecular oxygen transform aryl diazonium salts into aryl radicals. Experimental and computational studies show that Hantzsch esters transfer hydride to aryl diazonium species, and that oxygen initiates radical fragmentation of the diazene intermediate to produce aryl radicals. The operational simplicity of this addition-fragmentation process for the generation of aryl radicals, by a polar-radical crossover mechanism, has been illustrated in a variety of bond-forming reactions.
Direct synthesis of 2-arylazulenes by [8+2] cycloaddition of 2: H -cyclohepta [b] furan-2-ones with silyl enol ethers
Shoji, Taku,Sugiyama, Shuhei,Kobayashi, Yoshiaki,Yamazaki, Akari,Ariga, Yukino,Katoh, Ryuzi,Wakui, Hiroki,Yasunami, Masafumi,Ito, Shunji
supporting information, p. 1485 - 1488 (2020/02/13)
We developed a procedure for the direct synthesis of 2-arylazulenes, which were obtained in moderate to excellent yields, by [8+2] cycloaddition of 2H-cyclohepta[b]furan-2-ones with aryl-substituted silyl enol ethers. The structures of some 2-arylazulenes were clarified by single-crystal X-ray analysis. The 2-phenylazulene derivatives obtained by this study showed noticeable fluorescence in acidic media.
Aryl Pyrazoles from Photocatalytic Cycloadditions of Arenediazonium
Cardinale, Luana,Neumeier, Michael,Majek, Michal,Jacobi Von Wangelin, Axel
supporting information, p. 7219 - 7224 (2020/10/02)
A photocatalytic synthesis of 1,5-diaryl pyrazoles from arenediazoniums and arylcyclopropanols is reported. The reaction proceeded under mild conditions (rt, 20 min) with catalytic [Ru(bpy)3]2+ under blue-light irradiation and exhibited compatibility with several functional groups (e.g., I, SF5, SO2NH2, N3, CN) and perfect levels of regiocontrol. Mechanistic studies (luminescence spectroscopy, CV, DFT, radical trapping, quantum yield determination) documented an initial oxidative quenching of the excited photocatalyst and the operation of a radical-chain mechanism.
Palladium-Catalyzed [5 + 2] Annulation of Vinylethylene Carbonates with Barbiturate-Derived Alkenes
Chen, Yuehua,Deng, Hao,Gao, Xing,Guo, Hongchao,Jiang, Feng,Wang, Wei,Wu, Yongjun,Zhu, Dongyu
supporting information, p. 7158 - 7163 (2020/10/02)
A palladium/XantPhos-catalyzed [5 + 2] annulation of VECs with electron-deficient alkenes having an isolated carbon-carbon double bond has been developed to afford spirobarbiturate-tetrahydrooxepines. This study provides an expedient assembly of biologically interesting spirobarbiturate-tetrahydrooxepines. The easy scalability and versatile transformability of the reaction products were also exhibited.
C?O coupling of Malonyl Peroxides with Enol Ethers via [5+2] Cycloaddition: Non-Rubottom Oxidation
Vil', Vera A.,Gorlov, Evgenii S.,Bityukov, Oleg V.,Barsegyan, Yana A.,Romanova, Yulia E.,Merkulova, Valentina M.,Terent'ev, Alexander O.
supporting information, p. 3173 - 3181 (2019/05/15)
Malonyl peroxides act both as oxidants and reagents for C?O coupling in reactions with methyl and silyl enol ethers. In the proposed conditions, the oxidative C?O coupling of malonyl peroxides with enol ethers selectively proceeds, bypassing the traditional Rubottom hydroxylation of enol ethers by peroxides. It was observed that the oxidative [5+2] cycloaddition of malonyl peroxides and enol ethers is the key stage of the discovered process. Oxidative C?O coupling of silyl enol ethers leads to the formation of α-acyloxyketones with a free carboxylic acid group. A specially developed preparative one-pot procedure transforms ketones via silyl enol ethers formation and the following coupling into α-acyloxyketones with yields 35–88%. The acid-catalyzed coupling with methyl enol ethers gives remarkable products while retaining the easily oxidizable enol fragment. Furthermore, these molecules contain a free carboxylic acid group, thus these nontrivial products contain two usually incompatible acid and enol ether groups. (Figure presented.).
