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Andrew D. Smith - One of the best experts on this subject based on the ideXlab platform.
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isothiourea catalysed enantioselective pyrrolizine synthesis synthetic and computational studies
Organic and Biomolecular Chemistry, 2016Co-Authors: Daniel Graham Stark, Alexandra M. Z. Slawin, James E Taylor, Patrick Williamson, Emma R Gayner, Stefania Francesca Musolino, Ryan W F Kerr, Timothy J C Oriordan, Stuart Macgregor, Andrew D. SmithAbstract:The catalytic enantioselective synthesis of a range of cis-pyrrolizine carboxylate derivatives with outstanding stereocontrol (14 examples, >95 : 5 dr, >98 : 2 er) through an isothiourea-catalyzed Intramolecular Michael Addition-lactonisation and ring-opening approach from the corresponding enone acid is reported. An optimised and straightforward three-step synthetic route to the enone acid starting materials from readily available pyrrole-2-carboxaldehydes is delineated, with benzotetramisole (5 mol%) proving the optimal catalyst for the enantioselective process. Ring-opening of the pyrrolizine dihydropyranone products with either MeOH or a range of amines leads to the desired products in excellent yield and enantioselectivity. Computation has been used to probe the factors leading to high stereocontrol, with the formation of the observed cis-steroisomer predicted to be kinetically and thermodynamically favoured.
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enantioselective synthesis of 2 3 disubstituted trans 2 3 dihydrobenzofurans using a bronsted base thiourea bifunctional catalyst
Organic and Biomolecular Chemistry, 2016Co-Authors: Diego Javier Barrios Antunez, Alexandra M. Z. Slawin, Mark D Greenhalgh, Charlene Fallan, Andrew D. SmithAbstract:The diastereo- and enantioselective synthesis of 2,3-disubstituted trans-2,3-dihydrobenzofuran derivatives (15 examples, up to 96:4 dr, 95:5 er) via Intramolecular Michael Addition has been developed using keto–enone substrates and a bifunctional tertiary amine–thiourea catalyst. This methodology was extended to include non-activated ketone pro-nucleophiles for the synthesis of 2,3-disubstituted indane and 3,4-disubstituted tetrahydrofuran derivatives.
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stereodivergent organocatalytic Intramolecular Michael Addition lactonization for the asymmetric synthesis of substituted dihydrobenzofurans and tetrahydrofurans
Chemistry: A European Journal, 2014Co-Authors: Dorine Belmessieri, Alix De La Houpliere, Ewen D D Calder, James E Taylor, Andrew D. SmithAbstract:A stereodivergent asymmetric Lewis base cata- lyzed Michael Addition/lactonization of enone acids into sub- stituted dihydrobenzofuran and tetrahydrofuran derivatives is reported. Commercially available (S)-()-tetramisole hydro- chloride gives products with high syn diastereoselectivity in excellent enantioselectivity (up to 99:1 d.r.syn/anti ,9 9 % ee syn), whereas using a cinchona alkaloid derived catalyst gives the corresponding anti-diastereoisomers as the major product (up to 10:90 d.r.syn/anti ,9 9 % ee anti).
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organocatalytic functionalization of carboxylic acids isothiourea catalyzed asymmetric intra and intermolecular Michael Addition lactonizations
Journal of the American Chemical Society, 2011Co-Authors: Dorine Belmessieri, Carmen Simal, Louis C. Morrill, Alexandra M. Z. Slawin, Andrew D. SmithAbstract:Tetramisole promotes the catalytic asymmetric Intramolecular Michael Addition−lactonization of a variety of enone acids, giving carbo- and heterocyclic products with high diastereo- and enantiocontrol (up to 99:1 dr, up to 99% ee) that are readily derivatized to afford functionalized indene and dihydrobenzofuran carboxylates. Chiral isothioureas also promote the catalytic asymmetric intermolecular Michael Addition−lactonization of arylacetic acids and α-keto-β,γ-unsaturated esters, giving anti-dihydropyranones with high diastereo- and enantiocontrol (up to 98:2 dr, up to 99% ee).
Chuchi Tang - One of the best experts on this subject based on the ideXlab platform.
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bifunctional primary amine squaramide catalyzed enantioselective Intramolecular Michael Addition of keto enones a convenient process to the stereocontrolled construction of trans dihydrobenzofuran skeletons
ChemInform, 2014Co-Authors: Aidang Lu, Youming Wang, Haibin Song, Zhenghong Zhou, Keling Hu, Chuchi TangAbstract:The scalable, highly diastereo- and enantioselective title reaction proceeds smoothly to yield the trans-dibenzofuran derivatives (II) and (IV).
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bifunctional primary amine squaramide catalyzed enantioselective Intramolecular Michael Addition of keto enones a convenient process to the stereocontrolled construction of trans dihydrobenzofuran skeletons
European Journal of Organic Chemistry, 2013Co-Authors: Aidang Lu, Youming Wang, Haibin Song, Zhenghong Zhou, Keling Hu, Chuchi TangAbstract:A highly diasterero- and enantioselective Intramolecular Michael Addition of keto-enones has been realized. By using the (R,R)-1,2-diphenylethane-1,2-diamine-based bifunctional primary amine-squaramide catalyst, the reaction proceeded smoothly to generate the corresponding trans-2,3-disubstituted dihydrobenzofuran derivatives in excellent yields with good to excellent diastereo- and enantioselectivities (up to 97:3 dr, up to >99 % ee).
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enantioselective synthesis of trans dihydrobenzofurans via primary amine thiourea organocatalyzed Intramolecular Michael Addition
ChemInform, 2012Co-Authors: Youming Wang, Haibin Song, Zhenghong Zhou, Jianxin Fang, Chuchi TangAbstract:An efficient and highly enantioselective method to prepare trans-dihydrobenzofurans and trans-dihydronaphthofurans is reported.
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enantioselective synthesis of trans dihydrobenzofurans via primary amine thiourea organocatalyzed Intramolecular Michael Addition
Journal of Organic Chemistry, 2012Co-Authors: Youming Wang, Haibin Song, Zhenghong Zhou, Jianxin Fang, Chuchi TangAbstract:A primary amine-thiourea organocatalyzed Intramolecular Michael Addition access was developed for the synthesis of trans-dihydrobenzofurans. Under the catalysis of an (R,R)-1,2-diphenylethylamine derived primary amine-thiourea bearing a glucosyl scaffold, the corresponding trans-dihydrobenzofurans were obtained in high yields with excellent level of enantioselectivities (94 to >99% ee). Moreover, an in situ isomerization occurring at high temperature gave good to excellent trans/cis ratios as well (trans/cis: 84/16-96/4).
Youming Wang - One of the best experts on this subject based on the ideXlab platform.
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bifunctional primary amine squaramide catalyzed enantioselective Intramolecular Michael Addition of keto enones a convenient process to the stereocontrolled construction of trans dihydrobenzofuran skeletons
ChemInform, 2014Co-Authors: Aidang Lu, Youming Wang, Haibin Song, Zhenghong Zhou, Keling Hu, Chuchi TangAbstract:The scalable, highly diastereo- and enantioselective title reaction proceeds smoothly to yield the trans-dibenzofuran derivatives (II) and (IV).
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bifunctional primary amine squaramide catalyzed enantioselective Intramolecular Michael Addition of keto enones a convenient process to the stereocontrolled construction of trans dihydrobenzofuran skeletons
European Journal of Organic Chemistry, 2013Co-Authors: Aidang Lu, Youming Wang, Haibin Song, Zhenghong Zhou, Keling Hu, Chuchi TangAbstract:A highly diasterero- and enantioselective Intramolecular Michael Addition of keto-enones has been realized. By using the (R,R)-1,2-diphenylethane-1,2-diamine-based bifunctional primary amine-squaramide catalyst, the reaction proceeded smoothly to generate the corresponding trans-2,3-disubstituted dihydrobenzofuran derivatives in excellent yields with good to excellent diastereo- and enantioselectivities (up to 97:3 dr, up to >99 % ee).
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enantioselective synthesis of trans dihydrobenzofurans via primary amine thiourea organocatalyzed Intramolecular Michael Addition
ChemInform, 2012Co-Authors: Youming Wang, Haibin Song, Zhenghong Zhou, Jianxin Fang, Chuchi TangAbstract:An efficient and highly enantioselective method to prepare trans-dihydrobenzofurans and trans-dihydronaphthofurans is reported.
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enantioselective synthesis of trans dihydrobenzofurans via primary amine thiourea organocatalyzed Intramolecular Michael Addition
Journal of Organic Chemistry, 2012Co-Authors: Youming Wang, Haibin Song, Zhenghong Zhou, Jianxin Fang, Chuchi TangAbstract:A primary amine-thiourea organocatalyzed Intramolecular Michael Addition access was developed for the synthesis of trans-dihydrobenzofurans. Under the catalysis of an (R,R)-1,2-diphenylethylamine derived primary amine-thiourea bearing a glucosyl scaffold, the corresponding trans-dihydrobenzofurans were obtained in high yields with excellent level of enantioselectivities (94 to >99% ee). Moreover, an in situ isomerization occurring at high temperature gave good to excellent trans/cis ratios as well (trans/cis: 84/16-96/4).
Zhenghong Zhou - One of the best experts on this subject based on the ideXlab platform.
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bifunctional primary amine squaramide catalyzed enantioselective Intramolecular Michael Addition of keto enones a convenient process to the stereocontrolled construction of trans dihydrobenzofuran skeletons
ChemInform, 2014Co-Authors: Aidang Lu, Youming Wang, Haibin Song, Zhenghong Zhou, Keling Hu, Chuchi TangAbstract:The scalable, highly diastereo- and enantioselective title reaction proceeds smoothly to yield the trans-dibenzofuran derivatives (II) and (IV).
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bifunctional primary amine squaramide catalyzed enantioselective Intramolecular Michael Addition of keto enones a convenient process to the stereocontrolled construction of trans dihydrobenzofuran skeletons
European Journal of Organic Chemistry, 2013Co-Authors: Aidang Lu, Youming Wang, Haibin Song, Zhenghong Zhou, Keling Hu, Chuchi TangAbstract:A highly diasterero- and enantioselective Intramolecular Michael Addition of keto-enones has been realized. By using the (R,R)-1,2-diphenylethane-1,2-diamine-based bifunctional primary amine-squaramide catalyst, the reaction proceeded smoothly to generate the corresponding trans-2,3-disubstituted dihydrobenzofuran derivatives in excellent yields with good to excellent diastereo- and enantioselectivities (up to 97:3 dr, up to >99 % ee).
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enantioselective synthesis of trans dihydrobenzofurans via primary amine thiourea organocatalyzed Intramolecular Michael Addition
ChemInform, 2012Co-Authors: Youming Wang, Haibin Song, Zhenghong Zhou, Jianxin Fang, Chuchi TangAbstract:An efficient and highly enantioselective method to prepare trans-dihydrobenzofurans and trans-dihydronaphthofurans is reported.
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enantioselective synthesis of trans dihydrobenzofurans via primary amine thiourea organocatalyzed Intramolecular Michael Addition
Journal of Organic Chemistry, 2012Co-Authors: Youming Wang, Haibin Song, Zhenghong Zhou, Jianxin Fang, Chuchi TangAbstract:A primary amine-thiourea organocatalyzed Intramolecular Michael Addition access was developed for the synthesis of trans-dihydrobenzofurans. Under the catalysis of an (R,R)-1,2-diphenylethylamine derived primary amine-thiourea bearing a glucosyl scaffold, the corresponding trans-dihydrobenzofurans were obtained in high yields with excellent level of enantioselectivities (94 to >99% ee). Moreover, an in situ isomerization occurring at high temperature gave good to excellent trans/cis ratios as well (trans/cis: 84/16-96/4).
Haibin Song - One of the best experts on this subject based on the ideXlab platform.
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bifunctional primary amine squaramide catalyzed enantioselective Intramolecular Michael Addition of keto enones a convenient process to the stereocontrolled construction of trans dihydrobenzofuran skeletons
ChemInform, 2014Co-Authors: Aidang Lu, Youming Wang, Haibin Song, Zhenghong Zhou, Keling Hu, Chuchi TangAbstract:The scalable, highly diastereo- and enantioselective title reaction proceeds smoothly to yield the trans-dibenzofuran derivatives (II) and (IV).
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bifunctional primary amine squaramide catalyzed enantioselective Intramolecular Michael Addition of keto enones a convenient process to the stereocontrolled construction of trans dihydrobenzofuran skeletons
European Journal of Organic Chemistry, 2013Co-Authors: Aidang Lu, Youming Wang, Haibin Song, Zhenghong Zhou, Keling Hu, Chuchi TangAbstract:A highly diasterero- and enantioselective Intramolecular Michael Addition of keto-enones has been realized. By using the (R,R)-1,2-diphenylethane-1,2-diamine-based bifunctional primary amine-squaramide catalyst, the reaction proceeded smoothly to generate the corresponding trans-2,3-disubstituted dihydrobenzofuran derivatives in excellent yields with good to excellent diastereo- and enantioselectivities (up to 97:3 dr, up to >99 % ee).
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enantioselective synthesis of trans dihydrobenzofurans via primary amine thiourea organocatalyzed Intramolecular Michael Addition
ChemInform, 2012Co-Authors: Youming Wang, Haibin Song, Zhenghong Zhou, Jianxin Fang, Chuchi TangAbstract:An efficient and highly enantioselective method to prepare trans-dihydrobenzofurans and trans-dihydronaphthofurans is reported.
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enantioselective synthesis of trans dihydrobenzofurans via primary amine thiourea organocatalyzed Intramolecular Michael Addition
Journal of Organic Chemistry, 2012Co-Authors: Youming Wang, Haibin Song, Zhenghong Zhou, Jianxin Fang, Chuchi TangAbstract:A primary amine-thiourea organocatalyzed Intramolecular Michael Addition access was developed for the synthesis of trans-dihydrobenzofurans. Under the catalysis of an (R,R)-1,2-diphenylethylamine derived primary amine-thiourea bearing a glucosyl scaffold, the corresponding trans-dihydrobenzofurans were obtained in high yields with excellent level of enantioselectivities (94 to >99% ee). Moreover, an in situ isomerization occurring at high temperature gave good to excellent trans/cis ratios as well (trans/cis: 84/16-96/4).