28069-36-5Relevant academic research and scientific papers
Chemoselective biohydrogenation of α,β- and α,β,γ,δ-unsaturated ketones by the marine-derived fungus Penicillium citrinum CBMAI 1186 in a biphasic system
Ferreira, Irlon M.,Meira, Eloá B.,Rosset, Isac G.,Porto, André L.M.
, p. 59 - 65 (2015)
To broaden the range of applicability of a reduction reaction mediated by the marine fungal strain Penicillium citrinum CBMAI 1186 to organic chemical processes, the ability of whole mycelia to grow in biphasic mixtures with organic solvents was tested with acetone, ethyl acetate, n-butanol, dichloromethane, n-hexane and toluene. n-Hexane was the least toxic solvent according to the amount of mycelial mass grown in an artificial sea water medium mixed with each solvent. Therefore, whole hyphae of P. citrinum CBMAI 1186 were used as biocatalysts in the chemoselective biotransformation of the carbon-carbon double bond in α,β-, di-α,β-, and mono-α,β,γ,δ-unsaturated ketones (3a, 3c-f) in a biphasic system of phosphate buffer and n-hexane (9:1). Only the di-α,β,γ,δ-unsaturated ketone (3b) was not biocatalyzed under these conditions. In general, there were good conversions of saturated ketones by the enoate reductase enzymes of P. citrinum CBMAI 1186.
Palladium-catalyzed carbonylative/decarboxylative cross-coupling of α-bromo-ketones with allylic alcohols to γ,δ-unsaturated ketones
Peng, Jin-Bao,Wang, Le-Cheng,Wu, Xiao-Feng
, (2019)
In this communication, a palladium-catalyzed carbonylative/decarboxylative cross-coupling of α-bromo-ketones with allylic alcohols has been developed. With Mo(CO)6 as the CO source, γ,δ-unsaturated ketones were isolated in good yields. The release of CO2 was confirmed as well.
Z-Selective Synthesis of γ,δ-Unsaturated Ketones via Pd-Catalyzed Ring Opening of 2-Alkylenecyclobutanones with Arylboronic Acids
Zhou, Yao,Rao, Changqing,Song, Qiuling
, p. 4000 - 4003 (2016)
Pd-catalyzed 1,2-addition (instead of 1,4-addition) of arylboronic acids to 2-alkylenecyclobutanones followed by β-carbon elimination from the resulting palladium cyclobutanolates to afford γ,δ-unsaturated ketones was developed. The desired γ,δ-unsaturated ketones were obtained in good to excellent yields with Z/E selectivities of up to >99:1 and a broad spectrum of functional group tolerability.
Base-Catalyzed [1, n]-Proton Shifts in Conjugated Polyenyl Alcohols and Ethers
Molleti, Nagaraju,Martinez-Erro, Samuel,Carretero Cerdán, Alba,Sanz-Marco, Amparo,Gomez-Bengoa, Enrique,Martín-Matute, Belén
, p. 9134 - 9139 (2019)
The isomerization of dienyl alcohols and polyenyl alkyl ethers catalyzed by TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene) under metal-free conditions is presented. Two reaction pathways have been observed. For dienyl alcohols, the reaction proceeds by a [1,3]
Method for catalyzing non-tension non-polar carbon-carbon single bond hydrogenolysis of dicarbonyl compound
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Paragraph 0052-0057, (2021/08/06)
The invention belongs to the technical field of chemical engineering, and particularly relates to a method for catalyzing non-tension non-polar carbon-carbon single bond hydrogenolysis of a dicarbonyl compound. According to the method, in a rare earth catalysis system, a secondary alcohol (amine) compound or hydrosilyane is used as a hydrogen source, and non-tension carbon-carbon single bonds of diketone and ketone ester are subjected to hydrogenolysis to form monoketone (ester). The method is a first carbon-carbon bond hydrogenolysis reaction of ketone, and the reaction has the advantages of good atom economy, high position selectivity and chemical selectivity, mild conditions, simplicity and convenience in operation, strong functional group tolerance and the like. Diketone and ketone ester are wide in source, and application is wide when diketone and ketone ester are converted into monoketone (ester).
Selective Synthesis of Z-Silyl Enol Ethers via Ni-Catalyzed Remote Functionalization of Ketones
Guven, Sinem,Kundu, Gourab,Rissanen, Kari,Schoenebeck, Franziska,Ward, Jas S.,We?els, Andrea
supporting information, p. 8375 - 8380 (2021/06/27)
We report a remote functionalization strategy, which allows the Z-selective synthesis of silyl enol ethers of (hetero)aromatic and aliphatic ketones via Ni-catalyzed chain walking from a distant olefin site. The positional selectivity is controlled by the directionality of the chain walk and is independent of thermodynamic preferences of the resulting silyl enol ether. Our mechanistic data indicate that a Ni(I) dimer is formed under these conditions, which serves as a catalyst resting state and, upon reaction with an alkyl bromide, is converted to [Ni(II)-H] as an active chain-walking/functionalization catalyst, ultimately generating a stabilized η3-bound Ni(II) enolate as the key selectivity-controlling intermediate.
Diastereoselective and Stereodivergent Synthesis of 2-Cinnamylpyrrolines Enabled by Photoredox-Catalyzed Iminoalkenylation of Alkenes
Shen, Xu,Huang, Congcong,Yuan, Xiang-Ai,Yu, Shouyun
supporting information, p. 9672 - 9679 (2021/03/16)
A photoredox-catalyzed iminoalkenylation of γ-alkenyl O-acyl oximes has been developed. Readily available alkenylboronic acids serve as alkenylation reagents, leading to densely functionalized pyrrolines. Both (E)- and (Z)-cinnamylpyrrolines are accessible depending on the reaction solvent. In dichloromethane, (E)-cinnamylpyrrolines are produced through a photoredox-mediated single-electron-transfer process. In tetrahydrofuran, (Z)-cinnamylpyrrolines are generated by photocatalytic contra-thermodynamic E-to-Z isomerization of (E)-cinnamylpyrrolines though an energy-transfer pathway. Two stereocenters are established with complete diastereoselectivity and only one diastereomer is isolated.
Stereodivergent Nucleophilic Additions to Racemic β-Oxo Acid Derivatives: Fast Addition Outcompetes Stereoconvergence in the Archetypal Configurationally Unstable Electrophile
Crawford, Evan T.,De Jesús Cruz, Pedro,Johnson, Jeffrey S.,Liu, Shubin
supporting information, p. 16264 - 16273 (2021/10/21)
Additions of carbon nucleophiles to racemic α-stereogenic β-oxo acid derivatives that deliver enantiomerically enriched tertiary alcohols are valuable, but uncommon. This article describes stereodivergent Cu-catalyzed borylative cyclizations of racemic β-oxo acid derivatives bearing tethered pro-nucleophilic olefins to deliver highly functionalized cyclopentanols containing four contiguous stereogenic centers. The reported protocol is applicable to a range of β-oxo acid derivatives, and the diastereomeric products are readily isolable by typical chromatographic techniques. α-Stereogenic-β-keto esters are typically thought to have extreme or spontaneous configurational fragility, but mechanistic studies for this system reveal an unusual scenario wherein productive catalysis occurs on the same time scale as background substrate racemization and completely outcompetes on-cycle epimerization, even under the basic conditions of the reaction.
Chemoselective Hydrosilylation of the α,β-Site Double Bond in α,β- And α,β,γ,δ-Unsaturated Ketones Catalyzed by Macrosteric Borane Promoted by Hexafluoro-2-propanol
Zhan, Xiao-Yu,Zhang, Hua,Dong, Yu,Yang, Jian,He, Shuai,Shi, Zhi-Chuan,Tang, Lei,Wang, Ji-Yu
, p. 6578 - 6592 (2020/07/17)
The B(C6F5)3-catalyzed chemoselective hydrosilylation of α,β- and α,β,γ,δ-unsaturated ketones into the corresponding non-symmetric ketones in mild reaction conditions is developed. Nearly 55 substrates including those bearing reducible functional groups such as alkynyl, alkenyl, cyano, and aromatic heterocycles are chemoselectively hydrosilylated in good to excellent yields. Isotope-labeling studies revealed that hexafluoro-2-propanol also served as a hydrogen source in the process.
Radical Aza-Cyclization of α-Imino-oxy Acids for Synthesis of Alkene-Containing N-Heterocycles via Dual Cobaloxime and Photoredox Catalysis
Tu, Jia-Lin,Liu, Jia-Li,Tang, Wan,Su, Ma,Liu, Feng
supporting information, p. 1222 - 1226 (2020/02/15)
Nitrogen-containing heterocycles are prevalent in both naturally and synthetically bioactive molecules. We report herein an unprecedented protocol for radical aza-cyclization of α-imino-oxy acids with pendant alkenes via synergistic photoredox and cobaloxime catalysis. With or without alkenes as the intermolecular cross-coupling partners, the transformation provides a variety of corresponding alkene-containing dihydropyrrole products in satisfactory yields. In the presence of external alkenes, the tandem reaction generates E-selective coupling products with excellent chemo- and stereoselectivity.
