32443-55-3Relevant academic research and scientific papers
Organocatalyzed [2+2] Cycloaddition Reactions between Quinone Imine Ketals and Allenoates
Liu, Teng,He, Chixian,Wang, Fan,Shen, Xiang,Li, Yongqin,Lang, Man,Li, Guijun,Huang, Chao,Cheng, Feixiang
, p. 518 - 526 (2020/10/12)
A new cycloaddition reaction of quinone imine ketals (QIKs), which could be utilized to the construction of functionalized azaspirocyclics under mild conditions, is described. This transformation involved a [2+2] cycloaddition reaction between QIKs and allenoates catalyzed by DABCO, and then treatment with 1 N HCl in one-pot. The strategy could provide a practical route to access azetidine-fused spirohexadienones in good to excellent yields and with high E -selectivity.
Synthesis of vinylic sulfones in aqueous media
Goh, Jeffrey,Maraswami, Manikantha,Loh, Teck-Peng
supporting information, p. 1060 - 1065 (2021/02/16)
A green method for the sulfination of allenic carbonyl compounds to access a wide variety of vinylic sulfones is developed. This reaction works in aqueous media under very mild conditions. This reaction is atom economic. A wide variety of vinylic sulfones could be obtained in moderate to excellent yields with wide functional group tolerance. The efficiency of this method is demonstrated in some reactions where the desired products can be isolated by filtration.
DMAP Mediated Efficient Construction of Functionalized Chromenes through One-Pot Reaction of para-Quinone Methides with Allenoates
Song, Zefeng,Jia, Yuping,Zhang, Daizhou,Wang, De
, p. 1942 - 1948 (2021/04/05)
A novel DMAP-mediated Rauhut-Currier/oxa-Michael addition cascade reaction of hydroxylphenyl-substituted para-quinone methide with allenoate was reported for the first time. A series of functionalized chromenes were successfully obtained with moderate to
Visible-Light-Assisted Gold-Catalyzed Fluoroarylation of Allenoates
Feng, Chao,Tang, Hai-Jun,Zhang, Xinggui,Zhang, Yu-Feng
, p. 5242 - 5247 (2020/02/28)
A strategically novel synthetic method for the fluoroarylation of allenic ester was developed that enables the expedient construction of a host of β-fluoroalkyl-containing cinnamate derivatives. The reaction proceeds through visible-light-promoted gold redox catalysis, occurs smoothly under very mild reaction conditions, accommodates a large variety of functional groups, and more importantly allows the incorporation of fluorine and aryl groups with excellent regio- and stereoselectivity. The concomitant activation mode for both the allene motif and the hydrogen fluoride is key for the success of the reaction.
Phosphine-catalyzed dearomative [3+2] annulation of 3-nitroindoles and allenoates
Liu, Kui,Wang, Gang,Cheng, Shao-Jie,Jiang, Wen-Feng,He, Cheng,Ye, Zhi-Shi
, p. 1885 - 1890 (2019/06/21)
The efficient phosphine-catalyzed dearomative [3+2] annulation of 3-nitroindoles with allenoates has been successfully developed, providing a facile access to cyclopenta[b]indolines with good to excellent yields and high diastereoselectivities. This strategy features mild reaction conditions, high functional group tolerance, and scalability. Additionally, the 2-nitrobenzofuran and 2-nitrobenzothiophene were good dearomative [3+2] annulation partners.
A Tunable Route to Prepare α,β-Unsaturated Esters and α,β-Unsaturated-γ-Keto Esters through Copper-Catalyzed Coupling of Alkenyl Boronic Acids with Phosphorus Ylides
Bi, Hong-Yan,Liu, Feng-Ping,Liang, Cui,Su, Gui-Fa,Mo, Dong-Liang
, p. 1510 - 1516 (2018/03/05)
A tunable strategy to prepare α,β-unsaturated esters and α,β-unsaturated-γ-keto esters in good to excellent yields was developed through copper-catalyzed oxidative coupling of phosphorus ylides with alkenyl boronic acids under mild conditions. The reaction without water afforded α,β-unsaturated esters, ketones, and amides while α,β-unsaturated-γ-keto esters, 1,4-α,β-unsaturated diketones and α,β-unsaturated-γ-keto amides were obtained when using 5.0 equiv. of water. H2O18 labeling experiments showed that water played an important role in the formation of α,β-unsaturated-γ-keto esters. A plausible formation mechanism for α,β-unsaturated esters and α,β-unsaturated-γ-keto esters was proposed based on mechanistic studies. Phosphonium salts could also be used directly as coupling partners instead of phosphorus ylides. The reaction exhibited a broad substrate scope, good functional group tolerance, good regioselectivity, and diverse coupling products. (Figure presented.).
Nickel-catalyzed, ligand-free, diastereoselective synthesis of 3-methyleneindan-1-ols
Panchal, Heena,Clarke, Christopher,Bell, Charles,Karad, Somnath Narayan,Lewis, William,Lam, Hon Wai
supporting information, p. 12389 - 12392 (2018/11/20)
Nickel-catalyzed, highly diastereoselective annulations between activated allenes and 2-acetylarylboronic acid or 2-formylarylboronic acids are reported. No ligand for nickel is required, and the reactions proceed efficiently at room temperature to give a broad range of substituted 3-methyleneindan-1-ols. Preliminary results of an enantioselective variant are also described.
Asymmetric Oxy-Michael Addition to γ-Hydroxy-α,β-Unsaturated Carbonyls Using Formaldehyde as an Oxygen-Centered Nucleophile
Yoneda, Naoki,Hotta, Ayano,Asano, Keisuke,Matsubara, Seijiro
, p. 6264 - 6266 (2015/02/19)
Formaldehyde was utilized as an oxygen-centered nucleophile in an asymmetric oxy-Michael addition to γ-hydroxy-α,β-unsaturated carbonyl compounds using bifunctional organocatalysts through hemiacetal intermediates. The cyclic acetal product could be further transformed into β-hydroxycarbonyl compounds, useful synthetic intermediates leading to various important target molecules. As such, this method is an example of a novel formal asymmetric hydration of α,β-unsaturated carbonyl compounds.
Asymmetric synthesis of 1,3-oxazolidines via intramolecular aza-michael addition by bifunctional organocatalysts
Fukata, Yukihiro,Asano, Keisuke,Matsubara, Seijiro
, p. 355 - 357 (2013/05/09)
A novel synthetic route to optically active 1,3-oxazolidines via formal [3 + 2] cycloaddition in the presence of cinchonaalkaloid- thiourea-based bifunctional organocatalysts is reported. This protocol gives easy access to a wide range of chiral 1,3- oxazolidines. In addition, the results show that bifunctional organocatalysts can effect the intramolecular aza-Michael addition, leading to the asymmetric synthesis of nitrogencontaining heterocycles.
Procedure-controlled enantioselectivity switch in organocatalytic 2-oxazolidinone synthesis
Fukata, Yukihiro,Asano, Keisuke,Matsubara, Seijiro
supporting information, p. 12160 - 12163 (2013/09/23)
In a novel organocatalytic formal [3 + 2] cycloaddition to afford chiral 2-oxazolidinones, an enantioselectivity switch could be induced by changing the manner of addition of the reactants, even when the reaction components (cinchona-alkaloid-derived aminothiourea catalyst, substrates, and solvent) were the same.
