13565-44-1Relevant academic research and scientific papers
DBU-Catalyzed Rearrangement of Secondary Propargylic Alcohols: An Efficient and Cost-Effective Route to Chalcone Derivatives
De, Rimpa,Savarimuthu, Antony,Ballav, Tamal,Singh, Pijush,Nanda, Jayanta,Hasija, Avantika,Chopra, Deepak,Bera, Mrinal K.
supporting information, p. 1587 - 1592 (2020/08/28)
A 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed rearrangement of diarylated secondary propargylic alcohols to give α,β-unsaturated carbonyl compounds has been developed. The typical 1,3-transposition of oxy functionality, characteristic of Mayer-Schuster rearrangements, is not observed in this case. A broad substrate scope, functional-group tolerance, operational simplicity, complete atom economy, and excellent yields are among the prominent features of the reaction. Additionally, the photophysical properties and crystal-structure-packing behavior of selected compounds were investigated and found to be of interest.
Iodine-catalyzed α,β-dehydrogenation of ketones and aldehydes generating conjugated enones and enals
Cao, Yuanjie,Chen, Tieqiao,Huang, Tianzeng,Liu, Long
, p. 8697 - 8701 (2020/06/08)
A transition metal-free α,β-dehydrogenation of ketones and aldehydes was developed. This reaction was conducted in a facile I2/KI/DMSO system to produce the corresponding unsaturated compounds in good to high yields. The gram-scale experiment also indicated the potential synthetic value of this new reaction in organic synthesis. In the reaction, DMSO acted as both solvent and mild oxidant.
One-Pot Catalytic Enantioselective Synthesis of 2-Pyrazolines
Thomson, Connor J.,Barber, David M.,Dixon, Darren J.
supporting information, p. 2469 - 2473 (2019/02/01)
A scalable, one-pot, enantioselective catalytic synthesis of 2-pyrazolines from beta-substituted enones and hydrazines is described. Pivoting on a two-stage catalytic Michael addition/condensation strategy, the use of an aldehyde to generate a suitable hydrazone derivative of the hydrazine was found to be key for curtailing background reactivity and tuning the catalyst-controlled enantioselectivity. The new synthetic method is easy to perform, uses a new and readily prepared cinchona-derived bifunctional catalyst, is broad in scope, and tolerates a range of functionalities with high enantioselectivity (up to >99:1 e.r.). The significant scalability of this methodology was demonstrated with the synthesis of more than 80 grams of a pyrazoline product with 89 % catalyst recovery.
Studies of NMR Chemical Shifts of Chalcone Derivatives of Five-membered Monoheterocycles and Determination of Aromaticity Indices
Jeong, Eun Jeong,Lee, In-Sook Han
, p. 668 - 673 (2019/07/12)
A series of the chalcone derivatives of the five-membered monoheterocyclic compounds, (E)-1-aryl-3-heteroarylpropen-1-ones, were prepared by aldol condensation of the corresponding aldehydes of thiophene, pyrrole, and furan with m- and p-substituted acetophenones. Similar condensation of the acetyl compounds of the heterocycles with m- and p-substituted benzaldehydes gave another series of the chalcone derivatives, (E)-1-heteroaryl-3-arylpropen-1-ones. The 13C chemical shift values (δC) of the chalcone derivatives were determined in order to find if they correlated with the Hammett σ values. A good correlation, especially for the β-C for both series, was found for the 13C chemical shift values (δC) of the chalcone derivatives with the Hammett σ values. The chemical shift values of the β-C of the heterocyclic compounds were plotted against those of the benzene derivatives. The resulting slopes were found to be close to the values of the aromaticity indices.
Visible Light-Induced Aerobic Epoxidation of α,β-Unsaturated Ketones Mediated by Amidines
Wu, Yufeng,Zhou, Guangli,Meng, Qingwei,Tang, Xiaofei,Liu, Guangzhi,Yin, Hang,Zhao, Jingnan,Yang, Fan,Yu, Zongyi,Luo, Yi
, p. 13051 - 13062 (2018/10/25)
An aerobic photoepoxidation of α,β-unsaturated ketones driven by visible light in the presence of tetramethylguanidine (3b), tetraphenylporphine (H2TPP), and molecular oxygen under mild conditions was revealed. The corresponding α,β-epoxy ketones were obtained in yields of up to 94% in 96 h. The reaction time was shortened to 4.6 h by flow synthesis. The mechanism related to singlet oxygen was supported by experiments and density functional theory (DFT) calculations.
Iron-facilitated oxidative radical decarboxylative cross-coupling between α-oxocarboxylic acids and acrylic acids: An approach to α,β-unsaturated carbonyls
Jiang, Qing,Jia, Jing,Xu, Bin,Zhao, An,Guo, Can-Cheng
, p. 3586 - 3596 (2015/04/22)
The first Fe-facilitated decarboxylative cross-coupling reaction between α-oxocarboxylic acids and acrylic acids in aqueous solution has been developed. This transformation is characterized by its wide substrate scope and good functional group compatibility utilizing inexpensive and easily accessible reagents, thus providing an efficient and expeditious approach to an important class of α,β-unsaturated carbonyls frequently found in bioactive compounds. The synthetic potential of the coupled products is also demonstrated in subsequent functionalization reactions. Preliminary mechanism studies suggest that a free radical pathway is involved in this process: the generation of an acyl radical from α-oxocarboxylic acid via the excision of carbon dioxide followed by the addition of an acyl radical to the α-position of the double bond in acrylic acid then delivers the α,β-unsaturated carbonyl adduct through the extrusion of another carbon dioxide.
Gold(I)-catalyzed decarboxylation of propargyl carbonates: Reactivity reversal of the gold catalyst from π-Lewis acidity to σ-Lewis acidity
Shen, Ruwei,Yang, Jianjun,Zhu, Shugao,Chen, Chao,Wu, Luling
, p. 1259 - 1269 (2015/04/22)
A cationic gold(I)-catalyzed decarboxylative etherification of propargyl carbonates to selectively produce propargyl ethers is reported. In the reaction the gold(I) catalyst shows a distinct σ-Lewis acidity rather than the commonly observed π-Lewis acidity, and thus catalyzes the decarboxylation of a variety of propargyl carbonates to give the corresponding propargyl ethers with high selectivity. This reaction represents a rare example of the tunable reactivity of cationic gold(I) complexes between σ-Lewis acidity and π-Lewis acidity.
Copper-catalyzed oxidative coupling of alkenes with aldehydes: Direct access to α,β-unsaturated ketones
Wang, Jing,Liu, Chao,Yuan, Jiwen,Lei, Aiwen
supporting information, p. 2256 - 2259 (2013/04/10)
Let's get radical: The first copper-catalyzed oxidative coupling of alkenes and aldehydes was developed. Various aldehydes were utilized as substrates to construct α,β-unsaturated ketones. A preliminary mechanistic study indicated that this reaction is likely to proceed through a single-electron transfer. Copyright
Lead Tetraacetate Oxidation of Chalcone Oximes
Sharma, T. C.,Rojindar, S.,Berge, D. D.,Kale, A. V.
, p. 437 (2007/10/02)
Chalcone oximes (Ia-e) are oxidised by lead tetraacetate in dry benzene to afford the parent ketones (IIa-e) and the corresponding isoxazoles (IIIa-e).
Generation of Diastereomeric Cyclopropanes from Benzylidenesulfuranes and Chalcones
Stahl, Ingfried,Schomburg, Sabine,Kalinowski, Hans Otto
, p. 2247 - 2260 (2007/10/02)
The reaction of the benzylidenesulfuranes 2, available by deprotonation of the benzylsulfonium bromides 1, with chalcones 3, which are substituted in the aroyl part, leads to the stereoisomeric cyclopropanes 4 and 5.The stereochemistry of 4 and 5 is elucidated by spectroscopy.A carbenic mechanism of formation of 4 and 5 is excluded experimentally.
