scholarly journals Enantioselective Michael Addition of Aldehydes to Maleimides Organocatalyzed by a Chiral Primary Amine-Salicylamide

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3299 ◽  
Author(s):  
Alejandro Torregrosa-Chinillach ◽  
Adrien Moragues ◽  
Haritz Pérez-Furundarena ◽  
Rafael Chinchilla ◽  
Enrique Gómez-Bengoa ◽  
...  
Keyword(s):  
Michael Addition ◽  
Primary Amine ◽  
Room Temperature ◽  
Theoretical Calculations ◽  
Conjugate Addition ◽  
High Yields

A primary amine-salicylamide derived from chiral trans-cyclohexane-1,2-diamine was used as an organocatalyst for the enantioselective conjugate addition of aldehydes, mainly α,α-disubstituted to N-substituted maleimides. The reaction was performed in toluene as a solvent at room temperature. The corresponding enantioenriched adducts were obtained with high yields and enantioselectivities up to 94%. Theoretical calculations were used to justify the stereoinduction.

scholarly journals Organocatalytic Asymmetric Conjugate Addition of Aldehydes to Maleimides and Nitroalkenes in Deep Eutectic Solvents

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4058 ◽  
Author(s):  
Alejandro Torregrosa-Chinillach ◽  
Alba Sánchez-Laó ◽  
Elisa Santagostino ◽  
Rafael Chinchilla
Keyword(s):  
Primary Amine ◽  
Room Temperature ◽  
Deep Eutectic Solvents ◽  
Conjugate Addition ◽  
Reaction Media

A chiral primary amine-salicylamide is used as an organocatalyst for the enantioselective conjugate addition of α,α-disubstituted aldehydes to maleimides and nitroalkenes. The reactions are performed in deep eutectic solvents as reaction media at room temperature, leading to the corresponding adducts with enantioselectivities up to 88% (for maleimides) and 80% (for nitroalkenes). Catalyst and solvent can be recovered and reused.

Michael Addition of Aryl Thiols to 3-(2,2,2-Trifluoroethylidene)Oxindoles under Catalyst-Free Conditions: The Rapid Synthesis of Sulfur-Containing Oxindole Derivatives

2018 ◽  
Vol 42 (4) ◽  
pp. 210-214
Author(s):  
Bo Chen ◽  
Jiaheng Lei ◽  
Junling Zhao
Keyword(s):  
Michael Addition ◽  
Room Temperature ◽  
Rapid Synthesis ◽  
Efficient Catalyst ◽  
Mild Conditions ◽  
Catalyst Free ◽  
Wide Range ◽  
High Yields ◽  
The Michael Addition ◽  
Sulfur Containing

A mild and efficient catalyst-free method for the rapid synthesis at room temperature of 3-thiomethylated oxindole derivatives has been achieved via the Michael addition of aryl thiols to ring and 1-substituted 3-(2,2,2-trifluoroethylidene)oxindoles in dichloromethane. The method was applicable to a wide range of thiols and variously substituted 3-(2,2,2-trifluoroethylidene)oxindoles under mild conditions as demonstrated by the synthesis in high yields with good diastereoselectivities of 30 3-thiomethylated oxindoles bearing a trifluoromethyl group.

scholarly journals Highly Diastereoselective Cascade [5+1] Double Michael Reaction, a Route for The Synthesis of Spiro Thio-Oxindoles

2021 ◽  
Author(s):  
Firouz Matloubi Moghaddam ◽  
Vahid Saberi ◽  
Ashkan Karimi
Keyword(s):  
Room Temperature ◽  
Michael Reaction ◽  
Theoretical Calculations ◽  
Docking Studies ◽  
Binding Affinities ◽  
Diastereoselective Synthesis ◽  
Reaction Products ◽  
High Yields ◽  
Stereo Selectivity ◽  
Green Conditions

Abstract The first diastereoselective synthesis of spiro-thiooxindole is reported via Michael reaction between thiooxindoles and divinyl ketones. The reaction was conducted without any catalyst or additive under green conditions, i.e., ethanol as the solvent and room temperature. This study showed the art of governing regioselectivity in which novel spiro frameworks were generated in high yields. In addition to simple and column chromatography-free purification, the high diastereoselectivity makes this protocol very robust. The regio- and stereo- selectivity of the reaction has been discussed in light of the theoretical calculations, and molecular docking has been performed on the reaction products. Our method presents the first synthesis of cis-spiro thiooxindoles, which can be used to generate cis-spiro oxindoles. According to our docking studies, the latter demonstrates higher binding affinities towards the LdUMPS than corresponding trans-spiro oxindoles and may be utilized to develop new hit compounds for leishmaniasis treatment.

scholarly journals Chemoselective aza-Michael addition of indoles to 2-aroyl-1,3-diarylenones

2019 ◽  
Vol 44 (1-2) ◽  
pp. 97-103
Author(s):  
Zheng Li ◽  
Aizhen Yang ◽  
Xiaolong Ma ◽  
Zhenrong Liu
Keyword(s):  
Transition Metal ◽  
Michael Addition ◽  
Potassium Hydroxide ◽  
Room Temperature ◽  
Transition Metal Catalysts ◽  
Atom Economy ◽  
Mild Conditions ◽  
High Yields ◽  
Work Up ◽  
Aryl Methyl

A total of 20 examples of 2-[(1 H-indol-1-yl)(aryl)methyl]-1,3-diphenylpropane-1,3-diones were efficiently synthesized by the aza-Michael addition at the N1 position of indoles with 2-aroyl-1,3-diarylenones at room temperature in the presence of potassium hydroxide. The salient features of this protocol are no transition-metal catalysts, mild conditions, high chemoselectivity, high atom economy, high yields, and a simple work-up procedure.

Novel Brønsted Acidic Ionic Liquids Based on Benzimidazolium Cation: Synthesis and Catalyzed Conjugate Addition of Indoles with α,β-unsaturated Ketones

2011 ◽  
Vol 233-235 ◽  
pp. 977-984
Author(s):  
Bin Wang ◽  
Chen Jiang Liu
Keyword(s):  
Ionic Liquids ◽  
Michael Addition ◽  
Addition Reaction ◽  
Conjugate Addition ◽  
Michael Addition Reaction ◽  
Unsaturated Ketones ◽  
Mild Conditions ◽  
Acidic Ionic Liquids ◽  
High Yields ◽  
The Michael Addition

Brønsted acidic ionic liquids based on benzimidazolium cation was synthesized and employed as an efficient catalysts for the Michael addition reaction of indoles to α,β-unsaturated ketones under mild conditions to afford the corresponding conjugate addition products in high yields (90%-98%). The catalyst 1-butyl-3-(3-sulfopropyl)benzimidazolium p-toluenesulfonate ([PSbbim][p-CH3PhSO3]) could be reused at least three times without a noticeably decrease in its activity.

Copper-catalyzed 1,6-conjugate addition of para-quinone methides with diborylmethane

2021 ◽  
Author(s):  
Xin Li ◽  
Guoliang Gao ◽  
Songtao He ◽  
Qiuling Song
Keyword(s):  
Catalytic System ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
High Yields

Presented herein is the first 1,6-conjugate addition of diborylmethane, which is promoted by a simple and inexpensive copper catalytic system. This method features high yields, good selectivities and broad functional...

scholarly journals Nonreciprocal charge transport up to room temperature in bulk Rashba semiconductor α-GeTe

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yan Li ◽  
Yang Li ◽  
Peng Li ◽  
Bin Fang ◽  
Xu Yang ◽  
...  
Keyword(s):  
Charge Transport ◽  
Room Temperature ◽  
Theoretical Calculations ◽  
Ferromagnetic Layer ◽  
Spin Splitting ◽  
New Paradigm ◽  
Rashba Spin ◽  
Rashba Spin Splitting ◽  
Fundamental Insight ◽  
Insight Into

AbstractNonmagnetic Rashba systems with broken inversion symmetry are expected to exhibit nonreciprocal charge transport, a new paradigm of unidirectional magnetoresistance in the absence of ferromagnetic layer. So far, most work on nonreciprocal transport has been solely limited to cryogenic temperatures, which is a major obstacle for exploiting the room-temperature two-terminal devices based on such a nonreciprocal response. Here, we report a nonreciprocal charge transport behavior up to room temperature in semiconductor α-GeTe with coexisting the surface and bulk Rashba states. The combination of the band structure measurements and theoretical calculations strongly suggest that the nonreciprocal response is ascribed to the giant bulk Rashba spin splitting rather than the surface Rashba states. Remarkably, we find that the magnitude of the nonreciprocal response shows an unexpected non-monotonical dependence on temperature. The extended theoretical model based on the second-order spin–orbit coupled magnetotransport enables us to establish the correlation between the nonlinear magnetoresistance and the spin textures in the Rashba system. Our findings offer significant fundamental insight into the physics underlying the nonreciprocity and may pave a route for future rectification devices.

scholarly journals Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
The Other ◽  
Other Hand ◽  
Three Component Reaction ◽  
High Yields

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.

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