1120-72-5Relevant articles and documents
Optical Rotatory Dispersion Studies. 134. Absolute Configuration and Circular Dichroism Spectrum of (R)-Cyclopentanone. Demonstration of a Conformational Isotope Effect
Sundararaman, P.,Barth, Guenter,Djerassi, Carl
, p. 5004 - 5007 (1981)
The absolute configuration of (R)-cyclopentanone is established through synthesis using as the key step chiral epoxidation with the Sharpless reagent.Its circular dichroism (CD) spectrum is unusual in that it exhibits a bisignate Cotton effect being negative at 310 and positive at 275 nm.From the interpretation on the variable-temperature CD measurements, the unexpected conclusion is reached that the twist conformation with the deuterium in the quasi-equatorial position is energetically preferred by ca. 10 +/- 2 cal/mol.Evidently, even at room temperature, the contribution toward the spectrum resulting from the conformational isotope effect is of the same or larger amplitude but opposite sign compared to the difference between the partial octant contributions of an α-quasi-equatorial and α-quasi-axial deuterium substituent.
Synthesis of cycloalkanones from dienes and allylamines through C-H and C-C bond activation catalyzed by a rhodium(I) complex
Lee, Dae-Yon,Kim, In-Jung,Jun, Chul-Ho
, p. 3031 - 3033 (2002)
Formaldehyde in disguise: The allylic amine 1 is used as a masked form of formaldehyde in the rhodium-catalyzed cyclization of dienes 2. The reaction provides access to various cycloalkanones 3 through chelation-assisted C-H- and C-C-bond activation.
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Dreiding,Hartman
, p. 1216 (1956)
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Girard,C. et al.
, p. 3329 - 3332 (1974)
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Chemo- and regioselective conversion of epoxides to carbonyl compounds in 5 M lithium perchlorate-diethyl ether medium
Sudha,Malola Narasimhan,Geetha Saraswathy,Sankararaman
, p. 1877 - 1879 (1996)
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Brown,H.C.,Negishi,E.
, p. 5477 - 5478 (1967)
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Huang,S.L. et al.
, p. 297 - 299 (1978)
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The alkylation of silyl enol ethers with SN1-unreactive iodides in the presence of silver trifluoroacetate
Jefford, Charles W.,Sledeski, Adam W.,Lelandais, Patrick,Boukouvalas, John
, p. 1855 - 1858 (1992)
Silyl enol ethers can be effectively alkylated with primary n-alkyl iodides in the presence of silver trifluoro-acetate to give monoalkyl ketones.
Conversion of furfural into cyclopentanone over Ni-Cu bimetallic catalysts
Yang, Yanliang,Du, Zhongtian,Huang, Yizheng,Lu, Fang,Wang, Feng,Gao, Jin,Xu, Jie
, p. 1932 - 1940 (2013)
The conversion of furfural into cyclopentanone over Ni-Cu bimetallic catalysts was studied under hydrogen atmosphere. Furfuryl alcohol, 4-hydroxy-2-cyclopentenone and 2-cyclopentenone were verified as three key intermediates. Rearrangement of the furan ring was independent of hydrogenation, starting from furfuryl alcohol rather than furfural. The opening and closure of the furan ring were closely related to the attack of a H2O molecule on the 5-position of furfuryl alcohol. Prior hydrogenation of the aldehyde group accounted for the different reactivity of furfural and furfuryl alcohol. The high selectivity of cyclopentanone was ascribed to the presence of 2-cyclopentenone.
Synthesis of (1-S) and (1-R) cis 2-methylcyclopentanols through lipase mediated resolution
Reinhold,Rosati
, p. 1187 - 1190 (1994)
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Efficient and selective hydrogenation of biomass-derived furfural to cyclopentanone using Ru catalysts
Fang, Ruiqi,Liu, Hongli,Luque, Rafael,Li, Yingwei
, p. 4183 - 4188 (2015)
The selective hydrogenation of furfural into cyclopentanone is an attractive transformation to advance in the sustainable synthesis of important chemicals from biomass. A supported Ru nanoparticle catalyst on an acidic MOF material (Ru/MIL-101) was designed for the highly active and selective conversion of furfural to cyclopentanone in aqueous media. Complete conversion of furfural with a selectivity higher than 96% was achieved within 2.5 h at 160 °C and 4.0 MPa H2 pressure.
Muchamedova,Kudrjavceva
, (1968)
Overberger et al.
, p. 620 (1963)
Synthesis of Chiral Amines via a Bi-Enzymatic Cascade Using an Ene-Reductase and Amine Dehydrogenase
Fossey-Jouenne, Aurélie,Jongkind, Ewald P. J.,Mayol, Ombeline,Paul, Caroline E.,Vergne-Vaxelaire, Carine,Zaparucha, Anne
, (2021/12/23)
Access to chiral amines with more than one stereocentre remains challenging, although an increasing number of methods are emerging. Here we developed a proof-of-concept bi-enzymatic cascade, consisting of an ene reductase and amine dehydrogenase (AmDH), to afford chiral diastereomerically enriched amines in one pot. The asymmetric reduction of unsaturated ketones and aldehydes by ene reductases from the Old Yellow Enzyme family (OYE) was adapted to reaction conditions for the reductive amination by amine dehydrogenases. By studying the substrate profiles of both reported biocatalysts, thirteen unsaturated carbonyl substrates were assayed against the best duo OYE/AmDH. Low (5 %) to high (97 %) conversion rates were obtained with enantiomeric and diastereomeric excess of up to 99 %. We expect our established bi-enzymatic cascade to allow access to chiral amines with both high enantiomeric and diastereomeric excess from varying alkene substrates depending on the combination of enzymes.
Aqueous chemoenzymatic one-pot enantioselective synthesis of tertiary α-aryl cycloketonesviaPd-catalyzed C-C formation and enzymatic C=C asymmetric hydrogenation
Luan, Pengqian,Liu, Yunting,Li, Yongxing,Chen, Ran,Huang, Chen,Gao, Jing,Hollmann, Frank,Jiang, Yanjun
supporting information, p. 1960 - 1964 (2021/03/26)
An aqueous chemoenzymatic cascade reaction combining Pd-catalyzed C-C formation and enzymatic C=C asymmetric hydrogenation (AH) was developed for enantioselective synthesis of tertiary α-aryl cycloketones in good yields and excellent enantioselectivities. The stereopreference of the enzyme in AH of α-aryl cyclohexenones was studied. An enantiocomplementary enzyme was obtained by site-directed mutation.
Selective α-Methylation of Ketones
Frolov, Andriy I.,Ostapchuk, Eugeniy N.,Pashenko, Alexander E.,Chuchvera, Yaroslav O.,Rusanov, Eduard B.,Volochnyuk, Dmitriy M.,Ryabukhin, Sergey V.
, p. 7333 - 7346 (2021/06/28)
The convenient and scalable preparative approach for the two-step α-methylation of ketones is described. The optimized protocols for regioselective preparation of enaminones with further diastereoselective and functional groups tolerant hydrogenation to α-methylketones are developed. The scope and limitations of the proposed methodology are discussed. The advantages compared to known procedures are demonstrated. The unexpected role of acetone in the hydrogenation is suggested. The evaluation of the method for both early building block synthesis and late-stage CH-functionalization is shown. The elaborate procedures' preparability and scalability are demonstrated by the synthesis of several α-methyl ketones up to 100 g amount.