The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Alessandra Lattanzi - One of the best experts on this subject based on the ideXlab platform.
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amine thiourea catalysed double michael reaction an approach for the asymmetric synthesis of spiro pyrazolone 4 3 Tetrahydrothiophenes
Synthesis, 2017Co-Authors: Sara Meninno, Jacob Overgaard, Alessandra LattanziAbstract:A domino reaction, based on an organocatalysed sulfa-Michael/Michael sequence, is demonstrated as being useful for the asymmetric synthesis of spiro[pyrazolone-4,3′-Tetrahydrothiophenes] bearing three consecutive stereocentres. This new class of spirocyclic compounds has been synthesised in good yield and fairly good diastereo- and enantioselectivity by reacting α,β-unsaturated pyrazolones and tert-butyl (E)-4-mercapto-2-butenoate in the presence of a readily available secondary amine thiourea derived from (R,R)-1,2-diphenylethylenediamine.
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stereoselective amine thiourea catalysed sulfa michael nitroaldol cascade approach to 3 4 5 substituted Tetrahydrothiophenes bearing a quaternary stereocenter
Beilstein Journal of Organic Chemistry, 2016Co-Authors: Sara Meninno, Chiara Volpe, Giorgio Della Sala, Amedeo Capobianco, Alessandra LattanziAbstract:An investigation on the stereoselective cascade sulfa-Michael/aldol reaction of nitroalkenes and commercially available 1,4-dithiane-2,5-diol to 3,4,5-substituted Tetrahydrothiophenes, bearing a quaternary stereocenter, is presented. A secondary amine thiourea derived from (R,R)-1,2-diphenylethylamine was found to be the most effective catalyst when using trans-β-methyl-β-nitrostyrenes affording the heterocyclic products in good yields and moderate stereoselectivities.
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Stereoselective amine-thiourea-catalysed sulfa-Michael/nitroaldol cascade approach to 3,4,5-substituted Tetrahydrothiophenes bearing a quaternary stereocenter
Beilstein-Institut, 2016Co-Authors: Sara Meninno, Chiara Volpe, Giorgio Della Sala, Amedeo Capobianco, Alessandra LattanziAbstract:An investigation on the stereoselective cascade sulfa-Michael/aldol reaction of nitroalkenes and commercially available 1,4-dithiane-2,5-diol to 3,4,5-substituted Tetrahydrothiophenes, bearing a quaternary stereocenter, is presented. A secondary amine thiourea derived from (R,R)-1,2-diphenylethylamine was found to be the most effective catalyst when using trans-β-methyl-β-nitrostyrenes affording the heterocyclic products in good yields and moderate stereoselectivities
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Asymmetric Synthesis of Trisubstituted Tetrahydrothiophenes Bearing a Quaternary Stereocenter via Double Michael Reaction Involving Dynamic Kinetic Resolution
Organic Letters, 2013Co-Authors: Sara Meninno, Gianluca Croce, Alessandra LattanziAbstract:The stereoselective synthesis of highly functionalized Tetrahydrothiophenes bearing three contiguous stereocenters, one of them quaternary, can be achieved by reacting trans-α-cyano-α,β-unsaturated ketones and trans-tert-butyl 4-mercapto-2-butenoate in the presence of a readily available amine thiourea. The products are obtained in high yield, good diastereoselectivity, and excellent enantioselectivity. The overall formation of Tetrahydrothiophenes occurs via a cascade double Michael reaction involving a highly efficient process of dynamic kinetic resolution.
Sara Meninno - One of the best experts on this subject based on the ideXlab platform.
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amine thiourea catalysed double michael reaction an approach for the asymmetric synthesis of spiro pyrazolone 4 3 Tetrahydrothiophenes
Synthesis, 2017Co-Authors: Sara Meninno, Jacob Overgaard, Alessandra LattanziAbstract:A domino reaction, based on an organocatalysed sulfa-Michael/Michael sequence, is demonstrated as being useful for the asymmetric synthesis of spiro[pyrazolone-4,3′-Tetrahydrothiophenes] bearing three consecutive stereocentres. This new class of spirocyclic compounds has been synthesised in good yield and fairly good diastereo- and enantioselectivity by reacting α,β-unsaturated pyrazolones and tert-butyl (E)-4-mercapto-2-butenoate in the presence of a readily available secondary amine thiourea derived from (R,R)-1,2-diphenylethylenediamine.
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stereoselective amine thiourea catalysed sulfa michael nitroaldol cascade approach to 3 4 5 substituted Tetrahydrothiophenes bearing a quaternary stereocenter
Beilstein Journal of Organic Chemistry, 2016Co-Authors: Sara Meninno, Chiara Volpe, Giorgio Della Sala, Amedeo Capobianco, Alessandra LattanziAbstract:An investigation on the stereoselective cascade sulfa-Michael/aldol reaction of nitroalkenes and commercially available 1,4-dithiane-2,5-diol to 3,4,5-substituted Tetrahydrothiophenes, bearing a quaternary stereocenter, is presented. A secondary amine thiourea derived from (R,R)-1,2-diphenylethylamine was found to be the most effective catalyst when using trans-β-methyl-β-nitrostyrenes affording the heterocyclic products in good yields and moderate stereoselectivities.
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Stereoselective amine-thiourea-catalysed sulfa-Michael/nitroaldol cascade approach to 3,4,5-substituted Tetrahydrothiophenes bearing a quaternary stereocenter
Beilstein-Institut, 2016Co-Authors: Sara Meninno, Chiara Volpe, Giorgio Della Sala, Amedeo Capobianco, Alessandra LattanziAbstract:An investigation on the stereoselective cascade sulfa-Michael/aldol reaction of nitroalkenes and commercially available 1,4-dithiane-2,5-diol to 3,4,5-substituted Tetrahydrothiophenes, bearing a quaternary stereocenter, is presented. A secondary amine thiourea derived from (R,R)-1,2-diphenylethylamine was found to be the most effective catalyst when using trans-β-methyl-β-nitrostyrenes affording the heterocyclic products in good yields and moderate stereoselectivities
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Asymmetric Synthesis of Trisubstituted Tetrahydrothiophenes Bearing a Quaternary Stereocenter via Double Michael Reaction Involving Dynamic Kinetic Resolution
Organic Letters, 2013Co-Authors: Sara Meninno, Gianluca Croce, Alessandra LattanziAbstract:The stereoselective synthesis of highly functionalized Tetrahydrothiophenes bearing three contiguous stereocenters, one of them quaternary, can be achieved by reacting trans-α-cyano-α,β-unsaturated ketones and trans-tert-butyl 4-mercapto-2-butenoate in the presence of a readily available amine thiourea. The products are obtained in high yield, good diastereoselectivity, and excellent enantioselectivity. The overall formation of Tetrahydrothiophenes occurs via a cascade double Michael reaction involving a highly efficient process of dynamic kinetic resolution.
Dieter Enders - One of the best experts on this subject based on the ideXlab platform.
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diastereoselective synthesis of spiro pyrazolone 4 3 Tetrahydrothiophenes via a sulfa michael aldol domino reaction
Synthesis, 2016Co-Authors: Ugur Kaya, Suruchi Mahajan, Kari Rissanen, Janhendrik Schobel, Arto Valkonen, Dieter EndersAbstract:A new approach for the diastereoselective synthesis of spiro[pyrazolone-4,3′-Tetrahydrothiophenes] was developed. The N,N-diisopropylethylamine-catalyzed reaction of arylidenepyrazolones with in situ generated 2-sulfanylacetaldehyde provides the corresponding spiro-heterocycles via a domino sulfa-Michael/aldol reaction in 42–98% yield and 3:2:1 to 20:1 d.r. under mild reaction conditions.
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asymmetric synthesis of spiro tetrahydrothiophene indan 1 3 diones via a squaramide catalyzed sulfa michael aldol domino reaction
Synthesis, 2016Co-Authors: Suruchi Mahajan, Pankaj Chauhan, Marcus Blumel, Rakesh Puttreddy, Kari Rissanen, Gerhard Raabe, Dieter EndersAbstract:A new asymmetric domino sulfa-Michael/aldol reaction of 2-arylidene-1,3-indandiones with 1,4-dithiane-2,5-diol catalyzed by a sub-mol% loading of a squaramide provides a direct access to tetrahydrothiophene bearing spiro indane-1,3-dione derivatives in excellent yields and good stereoselectivities.
Hailong Yan - One of the best experts on this subject based on the ideXlab platform.
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enantioselective one pot synthesis of β sulfonyl ketones and trisubstituted Tetrahydrothiophenes via β elimination cycloaddition sequence
Chinese Chemical Letters, 2018Co-Authors: Lu Xue, Yidong Liu, Wenling Qin, Hailong YanAbstract:Abstract A mild and efficient enantioselective one-pot synthesis of β-sulfonyl ketones and trisubstituted Tetrahydrothiophenes via introducing 1,4-dithiane-2,5-diol to the simple kinetic resolution of β-sulfonyl ketones has been described herein. The one-pot reaction sequence including kinetic resolution and cascade sulfa-Michael/Aldol reaction proceeded successively to afford corresponding sulfonyl ketones and Tetrahydrothiophenes with high enantioselectivities (85%–98% ee and 84%–95% ee).
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asymmetric synthesis of trisubstituted Tetrahydrothiophenes via in situ generated chiral fluoride catalyzed cascade sulfa michael aldol reaction of 1 4 dithiane 2 5 diol and α β unsaturated ketones
Organic Letters, 2017Co-Authors: Mengying Duan, Yidong Liu, Lu Xue, Shilong Luo, Yu Tan, Wenling Qin, Choong Eui Song, Hailong YanAbstract:A chiral fluoride-catalyzed asymmetric cascade sulfa-Michael/aldol condensation reaction of 1,4-dithiane-2,5-diol and a series of α,β-unsaturated ketones is described to access chiral trisubstituted tetrahydrothiophene derivatives. The target products, including the spiro tetrahydrothiophene derivatives bearing a five-, six-, and seven-membered ring, were highly functionalized and showed high ee value. This established protocol realized a highly enantioselective reaction with a catalytic amount of KF and Song’s chiral oligoEG via in situ generated chiral fluoride to construct useful heterocyclic skeletons with great complexity.
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Asymmetric Synthesis of Trisubstituted Tetrahydrothiophenes via in Situ Generated Chiral Fluoride-Catalyzed Cascade Sulfa-Michael/Aldol Reaction of 1,4-Dithiane-2,5-diol and α,β-Unsaturated Ketones
2017Co-Authors: Mengying Duan, Yidong Liu, Lu Xue, Shilong Luo, Yu Tan, Wenling Qin, Choong Eui Song, Hailong YanAbstract:A chiral fluoride-catalyzed asymmetric cascade sulfa-Michael/aldol condensation reaction of 1,4-dithiane-2,5-diol and a series of α,β-unsaturated ketones is described to access chiral trisubstituted tetrahydrothiophene derivatives. The target products, including the spiro tetrahydrothiophene derivatives bearing a five-, six-, and seven-membered ring, were highly functionalized and showed high ee value. This established protocol realized a highly enantioselective reaction with a catalytic amount of KF and Song’s chiral oligoEG via in situ generated chiral fluoride to construct useful heterocyclic skeletons with great complexity
Junbing Ling - One of the best experts on this subject based on the ideXlab platform.
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organocatalytic cascade sulfa michael aldol reaction of β β disubstituted enones enantioselective synthesis of Tetrahydrothiophenes with a trifluoromethylated quaternary center
Journal of Organic Chemistry, 2013Co-Authors: Junbing Ling, Shuang ZhangAbstract:A bifunctional squaramide-catalyzed sulfa-Michael/aldol cascade reaction initiated by sulfa-Michael addition of mercaptoacetaldehyde to β-aryl-β-trifluoromethylated enones is successfully developed. The functionalized Tetrahydrothiophenes with three continuous stereocenters including a trifluoromethylated quaternary carbon are readily obtained with moderate to good yields and high enantioselectivities.
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Organocatalytic Cascade Sulfa-Michael/Aldol Reaction of β,β‑Disubstituted Enones: Enantioselective Synthesis of Tetrahydrothiophenes with a Trifluoromethylated Quaternary Center
2013Co-Authors: Junbing Ling, Shuang ZhangAbstract:A bifunctional squaramide-catalyzed sulfa-Michael/aldol cascade reaction initiated by sulfa-Michael addition of mercaptoacetaldehyde to β-aryl-β-trifluoromethylated enones is successfully developed. The functionalized Tetrahydrothiophenes with three continuous stereocenters including a trifluoromethylated quaternary carbon are readily obtained with moderate to good yields and high enantioselectivities
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hydrogen bond mediated cascade reaction involving chalcones facile synthesis of enantioenriched trisubstituted Tetrahydrothiophenes
Organic Letters, 2012Co-Authors: Junbing Ling, Hailiang Zhu, Guanyu WangAbstract:A bifunctional squaramide catalyzed sulfa-Michael/aldol cascade reaction between 1,4-dithiane-2,5-diol and chalcones with a low catalyst loading has been developed. Trisubstituted Tetrahydrothiophenes with three contiguous stereogenic centers are obtained in a highly stereocontrolled manner. Additionally, a remarkable temperature effect on reaction efficiency was observed and a synthetically potential gram-synthesis was also conducted.
