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Hans Adolfsson - One of the best experts on this subject based on the ideXlab platform.
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chiral quinuclidine based amine catalysts for the asymmetric one pot three component aza Baylis Hillman Reaction
Tetrahedron Letters, 2003Co-Authors: Daniela Balan, Hans AdolfssonAbstract:Chiral quinuclidine-based amine catalysts for the asymmetric one-pot, three-component aza-Baylis–Hillman Reaction
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Chiral quinuclidine-based amine catalysts for the asymmetric one-pot, three-component aza-Baylis–Hillman Reaction
Tetrahedron Letters, 2003Co-Authors: Daniela Balan, Hans AdolfssonAbstract:Chiral quinuclidine-based amine catalysts for the asymmetric one-pot, three-component aza-Baylis–Hillman Reaction
Palakodety Radha Krishna - One of the best experts on this subject based on the ideXlab platform.
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Asymmetric Baylis-Hillman Reaction : An Enchanting Expedition
Synlett, 2008Co-Authors: Palakodety Radha Krishna, Rachna Sachwani, Purumandla Srinivas ReddyAbstract:The development of new strategies for realizing the asymmetricBaylis-Hillman Reaction remains at the forefront of researchinto this important organic Reaction. This review gives a comprehensiveaccount of the work that has emanated from our group on the asymmetricBaylis-Hillman Reaction. Herein, the use of homochiralelectrophiles, Michael acceptors, and bases and double asymmetricinduction protocols as tools for the asymmetric Baylis-HillmanReaction is discussed. The account also covers the application ofsuch protocols in natural product synthesis. 1 Introduction 2 Asymmetric Baylis-Hillman Reaction: A Personal Account 2.1 Homochiral Electrophiles 2.1.1 Sugar-Derived Aldehydes 2.1.2 Chiral 2,3-Epoxy Aldehydes 2.2 Homochiral Michael Acceptors 2.2.1 TADDOL Acrylates 2.2.2 Sugar-Derived Acrylates 2.2.3 A Sugar-Derived Lactone 2.3 Homochiral Catalysts 2.3.1 N-Methylprolinol as the ChiralCatalyst 2.3.2 Other Chiral Catalysts 2.4 Double Asymmetric Induction 2.5 Applications 2.5.1 α-Methylene-β-hydroxylactones via anIntramolecular Baylis-Hillman Reaction 2.5.2 Synthesis of Syributins 2.5.3 Sequential Baylis-Hillman Reaction and Ring-Closing Metathesisas a Protocol for Sugar-Linked α,β-Unsaturated γ-LactoneLibrary Generation 2.5.4 Synthesis of Non-natural Higher-Carbon Sugars 3 Conclusion
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The Baylis–Hillman Reaction: a strategic tool for the synthesis of higher-carbon sugars☆
Tetrahedron Letters, 2007Co-Authors: Palakodety Radha Krishna, P.v. Narasimha Reddy, Aare Sreeshailam, M. Uday Kiran, B. JagdeeshAbstract:Abstract The Baylis–Hillman Reaction of acyclic sugar-derived aldehydes is invoked as an attractive synthetic strategy for ready access to higher-carbon sugars.
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Steric determinants in diastereocontrol during Baylis–Hillman Reaction of sugar-derived aldehydes
Tetrahedron: Asymmetry, 2005Co-Authors: Palakodety Radha Krishna, A. Manjuvani, V. KannanAbstract:Abstract Diastereoselective Baylis–Hillman Reaction using different sugar-derived aldehydes with various activated olefins afforded chiral multifunctional adducts in good yields. Steric factors that dictate and determine the diastereoselection will be discussed.
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Novel aprotic polar solvents for facile Baylis-Hillman Reaction
Arkivoc, 2004Co-Authors: Palakodety Radha Krishna, A. Manjuvani, Empati Raja SekharAbstract:Novel aprotic polar solvents are selected for use towards a facile Baylis-Hillman Reaction catalyzed by the standard base (DABCO) at room temperature so that less reactive aldehydes and a broad spectrum of activated olefins (including acrylamide) could be coupled under the altered Reaction conditions.
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N-Methylmorpholine and urotropine as useful base catalysts in Baylis-Hillman Reaction
Synthesis, 2004Co-Authors: Palakodety Radha Krishna, Empati Raja Sekhar, V. KannanAbstract:N-Methylmorpholine and urotropine, inexpensive mild bases, have effectively been utilized as catalysts in Baylis-Hillman Reaction to result in good to excellent yields (57-99%) of the products.
Daniela Balan - One of the best experts on this subject based on the ideXlab platform.
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chiral quinuclidine based amine catalysts for the asymmetric one pot three component aza Baylis Hillman Reaction
Tetrahedron Letters, 2003Co-Authors: Daniela Balan, Hans AdolfssonAbstract:Chiral quinuclidine-based amine catalysts for the asymmetric one-pot, three-component aza-Baylis–Hillman Reaction
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Chiral quinuclidine-based amine catalysts for the asymmetric one-pot, three-component aza-Baylis–Hillman Reaction
Tetrahedron Letters, 2003Co-Authors: Daniela Balan, Hans AdolfssonAbstract:Chiral quinuclidine-based amine catalysts for the asymmetric one-pot, three-component aza-Baylis–Hillman Reaction
V. Kannan - One of the best experts on this subject based on the ideXlab platform.
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Steric determinants in diastereocontrol during Baylis–Hillman Reaction of sugar-derived aldehydes
Tetrahedron: Asymmetry, 2005Co-Authors: Palakodety Radha Krishna, A. Manjuvani, V. KannanAbstract:Abstract Diastereoselective Baylis–Hillman Reaction using different sugar-derived aldehydes with various activated olefins afforded chiral multifunctional adducts in good yields. Steric factors that dictate and determine the diastereoselection will be discussed.
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N-Methylmorpholine and urotropine as useful base catalysts in Baylis-Hillman Reaction
Synthesis, 2004Co-Authors: Palakodety Radha Krishna, Empati Raja Sekhar, V. KannanAbstract:N-Methylmorpholine and urotropine, inexpensive mild bases, have effectively been utilized as catalysts in Baylis-Hillman Reaction to result in good to excellent yields (57-99%) of the products.
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Sulpholane––A new solvent for the Baylis–Hillman Reaction☆
Tetrahedron Letters, 2004Co-Authors: Palakodety Radha Krishna, A. Manjuvani, V. Kannan, G. V. M. SharmaAbstract:Abstract Sulpholane, a commercially available solvent, is used for the first time as a new solvent for the Baylis–Hillman Reaction under ambient conditions; a wide variety of olefins as well as aldehydes participate very efficiently resulting in good to excellent yields of products. Acrylamide also underwent the Baylis–Hillman Reaction with 4-nitrobenzaldehyde under these Reaction conditions.
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N‐Methylprolinol Catalysed Asymmetric Baylis−Hillman Reaction
Advanced Synthesis & Catalysis, 2004Co-Authors: Palakodety Radha Krishna, V. Kannan, P.v. Narasimha ReddyAbstract:N-methylprolinol is used as a chiral base catalyst for the Baylis–Hillman Reaction to obtain the adducts in good yields with moderate to good enantioselectivities in 1,4-dioxane:water (1 : 1, v/v) under ambient conditions.
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Diastereoselective Baylis-Hillman Reaction: Use of Sugar Derived Aldehydes as Chiral Electrophiles
Synlett, 2003Co-Authors: Palakodety Radha Krishna, V. Kannan, Gangavaram V. M. Sharma, M. H. V. Ramana RaoAbstract:The asymmetric Baylis-Hillman Reaction of sugar-derived aldehydes as chiral electrophiles with an activated olefin in dioxane: water (1:1) with 36-86% de and in good yields is described.
Min Shi - One of the best experts on this subject based on the ideXlab platform.
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The Chemistry of the Morita-Baylis-Hillman Reaction
2011Co-Authors: Min Shi, Feijun Wang, Mei-xin Zhao, Yin WeiAbstract:Morita-Baylis-Hillman Reaction Catalytic System for the Morita-Baylis-Hillman Reaction Transformations of Functional Groups in Morita-Baylis-Hillman Adducts Morita-Baylis-Hillman Adducts or Derivatives for the Construction of Cyclic Frameworks The application of Morita-Baylis-Hillman Reaction for the Synthesis of Natural Products
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chiral thiourea phosphine organocatalysts in the asymmetric aza morita Baylis Hillman Reaction
Advanced Synthesis & Catalysis, 2007Co-Authors: Yongling Shi, Min ShiAbstract:A new kind of bifunctional (thio)ureapbosphine catalyst was synthesized and applied to the aza-Morita-Baylis-Hillman Reaction of N-sulfonated imines with methyl vinyl ketone, phenyl vinyl ketone, ethyl vinyl ketone or acrolein. Moderate to excellent ee and yields of the products were obtained under mild Reaction conditions.
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chiral phosphine lewis base catalyzed asymmetric aza Baylis Hillman Reaction of n sulfonated imines with methyl vinyl ketone and phenyl acrylate
Chemical Communications, 2003Co-Authors: Min Shi, Lianhui ChenAbstract:In the aza-Baylis–Hillman Reaction of N-sulfonated imines with methyl vinyl ketone (MVK) promoted by chiral phosphine Lewis base: (R)-2′-diphenylphosphanyl-[1,1′]binaphthalenyl-2-ol (10 mol%), the aza-Baylis–Hillman adducts 1 were obtained in good yields with high ee (70–94% ee) at −30 °C in THF. In CH2Cl2 upon heating at 40 °C, the aza-Baylis–Hillman Reaction of N-sulfonated imines with phenyl acrylate gave the adducts 2 in high yields (60–97%) with moderate ee (52–77%).
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Reexamination of the traditional Baylis-Hillman Reaction
Tetrahedron, 2003Co-Authors: Min Shi, Jian-kang JiangAbstract:Abstract In the Baylis–Hillman Reaction of arylaldehydes with methyl vinyl ketone (MVK), we found that, besides the normal Baylis–Hillman adduct 1 , the diadduct 2 can also be formed at the same time and the yield of 2 can reach to 55% if increasing the amount of methyl vinyl ketone. But for ethyl vinyl ketone (EVK), methyl acrylate or acrylonitrile, only the normal Baylis–Hillman adduct 4 , 7 or 8 was obtained, respectively. The substituent's effects and Lewis base effects were also examined and a plausible Reaction mechanism was proposed for the formation of 2 .
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Lewis Base Effects in the Baylis−Hillman Reaction of Imines with Methyl Vinyl Ketone
European Journal of Organic Chemistry, 2002Co-Authors: Min ShiAbstract:In the Baylis-Hillman Reaction of N-benzylidene-4-methylbenzenesulfonamide with methyl vinyl ketone (MVK), we found that, in the presence of a catlytic amount of DMAP, PPh^3 or DABCO as Lewis base, jthe Baylis-Hillman Reaction can be greatly accelerated to give the normmal Baylis-Hillman adducts 1 in good or jvery jhigh yields. However, with Pbu^3 as a Lewis base, the abnormal Baylis-Hillman adducts 2 and 3 were formed under the same Reaction condition. The effect of the substituents was also examined and a plausible Reaction mechanism proposed.