25522-79-6Relevant academic research and scientific papers
A convenient synthesis of α-functional alkyl vinyl ketones
Ben Ayed,Amri
, p. 3813 - 3819 (1995)
Reaction of 2-functional alkyl-1,3-ketones with 30% aqueous formaldehyde using aqueous 6-10M potassium carbonate solution as base, afforded α-functional alkyl vinyl ketones in good yields.
Asymmetric Catalytic Epoxidation of Terminal Enones for the Synthesis of Triazole Antifungal Agents
Feng, Xiaoming,He, Qianwen,Liu, Xiaohua,Zhang, Dong,Zhang, Fengcai
supporting information, p. 6961 - 6966 (2021/09/11)
An enantioselective epoxidation of α-substituted vinyl ketones was realized to construct the key epoxide intermediates for the synthesis of various triazole antifungal agents. The reaction proceeded efficiently in high yields with good enantioselectivities by employing a chiral N,N′-dioxide/ScIII complex as the chiral catalyst and 35% aq. H2O2 as the oxidant. It enabled the facile transformation for optically active isavuconazole, efinaconazole, and other potential antifungal agents.
Polycyclic Polyprenylated Acylphloroglucinols: An Emerging Class of Non-Peptide-Based MRSA- and VRE-Active Antibiotics
Guttroff, Claudia,Baykal, Aslihan,Wang, Huanhuan,Popella, Peter,Kraus, Frank,Biber, Nicole,Krauss, Sophia,G?tz, Friedrich,Plietker, Bernd
supporting information, p. 15852 - 15856 (2017/11/23)
In the past 20 years, peptide-based antibiotics, such as vancomycin, teicoplanin, and daptomycin, have often been considered as second-line antibiotics. However, in recent years, an increasing number of reports on vancomycin resistance in pathogens appear
Bioreduction of α-Acetoxymethyl Enones: Proposal for an SN2′ Mechanism Catalyzed by Enereductase
Paula, Bruno R. S.,Zampieri, Davila,Rodrigues, J. Augusto R.,Moran, Paulo J. S.
, p. 3555 - 3571 (2016/11/25)
(Z)-3-Acetoxymethyl-4-R-3-buten-2-ones (R=aryl, alkyl) and (Z)-3-methyl-4-R-3-buten-2-ones (R=aryl) were synthesized and submitted to reduction by the yeast Saccharomyces cerevisiae producing the (R)- and (S)-4-R-3-methybutan-2-ones, respectively. This stereochemistry control strategy was applied in the syntheses of (R)- and (S)-Tropional with moderate to high enantiomeric excesses. Other (Z)-3-acyloxymethyl-4-phenyl-3-buten-2-ones showed similar behavior to the (Z)-3-acetoxymethyl counterpart, and the acylated Morita–Baylis–Hillman adduct 1-acetoxy-2-methylene-1-phenylbutan-3-one produced a mixture of products, with and without the acetoxy group, via three different reaction pathways. In addition to experiments employing whole cells, those in which isolated enereductases were used suggested that the main pathway through which the loss of the acetoxy group occurs during the biocatalytic cascade is an SN2′-type reaction, rather than formal hydrogen addition followed by acetic acid elimination. Finally, related ethyl enones were reduced enantioselectively by the yeast Candida albicans, producing both (R)- and (S)-reduction products, depending on the presence of the acetoxy group in the starting material. (Figure presented.).
Enantiodivergence in the reduction of α-methyl and α-halomethyl enones by microorganisms
De Paula, Bruno R.S.,Zampieri, Davila S.,Rodrigues, J. Augusto R.,Moran, Paulo J.S.
, p. 973 - 981 (2013/09/23)
Enones (Z)-3-methyl-(Z)-3-chloromethyl- and (Z)-3-bromomethyl-4-R-3-buten- 2-one (R = n-pentyl, phenyl, 2′- and 4′-chlorophenyl, 3′- and 4′-nitrophenyl, 4′-methoxyphenyl) were synthesized and subjected to reduction by the microorganisms Saccharomyces cerevisiae andGeotrichum candidum. Whereas the bioreduction of 3-methy-4-R-3-buten-2-ones afforded the corresponding (S)-4-R-3-methybutan-2-ones, the bioreduction of 3-chloromethyl- and 3-bromomethyl-4-R-3-buten-2-ones afforded the corresponding (R)-4-R-3-methybutan-2-ones.
Rhodium(III)-catalyzed synthesis of pyridines from α,β- unsaturated ketoximes and internal alkynes
Too, Pei Chui,Noji, Toshiharu,Lim, Ying Jie,Li, Xingwei,Chiba, Shunsuke
supporting information; experimental part, p. 2789 - 2794 (2012/01/11)
A method for the synthesis of highly substituted pyri-dines from ,-unsaturated oximes and internal alkynes has been developed using [Cp*RhCl2]2-CsOPiv as the catalyst system. The present transformation is carried out by a redox-neutral sequence of vinylic C-H rhodation, alkyne insertion, and C-N bond formation of the putative vinyl rhodium intermediate with the oxime nitrogen, where the N-O bond of oxime derivatives could work as an internal oxidant to maintain the catalytic cycle. Georg Thieme Verlag Stuttgart · New York.
Efficient α-methylenation of carbonyl compounds in ionic liquids at room temperature
Vale, Juliana A.,Zanchetta, Daniel F.,Moran, Paulo J. S.,Rodrigues, J. Augusto R.
experimental part, p. 75 - 78 (2009/05/30)
The application of several 1-butyl-3-methylimidazolium (BMIM) salt ionic liquids as solvent in the α-methylenation of carbonyl compounds at room temperature is reported. The ionic liquid [BMIM][NTf2] gave a clean reaction in a short time and good yields of several α-methylene carbonyl compounds. This ionic liquid was reused without affecting the reaction rates or yields over seven runs. Georg Thieme Verlag Stuttgart.
Highly enantioselective synthesis of optically active ketones by iridium-catalyzed asymmetric hydrogenation
Lu, Sheng-Mei,Bolm, Carsten
supporting information; experimental part, p. 8920 - 8923 (2009/05/30)
(Chemical Equation Presented) Close to perfect enantioselectivity (up to 99% ee, see scheme) is found for the formation of α-substituted ketones by the asymmetric hydrogenation of enones with an iridium-phosphinooxazoline catalyst. In an operationally simple process, both linear and cyclic substrates react well and afford the desired products in high yields. A wide variety of substituents are tolerated, thus making the method synthetically appealing.
An efficient synthesis of α-branched enones
Kummer, David A.,Brenneman, Jehrod B.,Martin, Stephen F.
, p. 1431 - 1433 (2007/10/03)
A new method for preparing α-branched enones from carboxylic acid derivatives is reported. The procedure commenced by the reaction of N,O-dimethylamides with a masked acyl anion equivalent, followed by the addition of (trimethylsilyl-methyl)cerium dichloride to give intermediates that undergo Lewis acid mediated olefination to produce enol ethers that are then hydrolyzed to afford simple α-branched enones in high overall yields.
Preparation and regioselective SN2′ reaction of novel gem-difluorinated vinyloxiranes with RLi
Ueki, Hisanori,Chiba, Takashi,Yamazaki, Takashi,Kitazume, Tomoya
, p. 7616 - 7627 (2007/10/03)
A series of hitherto unknown 3,4-epoxy-1,1-difluorobutenes were prepared from the readily accessible α,β-epoxy ketones and these compounds were found to undergo regioselective SN2′ reactions with hard RLi nucleophiles occurring at the highly positively charged terminal fluorine-possessing sp2 carbon atom in quite sharp contrast to the cases of the corresponding nonfluorinated vinyloxiranes which only attained a low level of regioselectivity. Addition of HMPA substantially improved the products' olefinic stereoselectivity. Theoretical calculations were used to qualitatively explore the nature of selectivity in these reactions.
