Shu Kobayashi

Bio: Shu Kobayashi is an academic researcher from University of Tokyo. The author has contributed to research in topics: Aldol reaction & Enol. The author has an hindex of 18, co-authored 70 publications receiving 890 citations.

The efficient catalytic asymmetric aldol-type reaction

Abstract: A wide variety of aldehydes including aromatic, aliphatic and α,β-unsaturated aldehydes react with silyl enol ether of S-ethyl propanethioate in propionitrile to afford the corresponding aldol-type adducts with high relative and absolute stereochemical control by use of chiral diamine coordinated tin(II) triflate as a catalyst.

Catalytic Asymmetric Aldol Reaction of Silyl Enol Ethers with Aldehydes by the Use of Chiral Diamine Coordinated Tin(II) Triflate

Abstract: Highly enantioselective aldol reaction of silyl enol ethers with aldehydes is performed by the use of a catalytic amount of chiral diamine coordinated tin(II) triflate according to a slow addition procedure.

An efficient method for the preparation of threo cross-aldols from silyl enol ethers and aldehydes using trityl perchlorate as a catalyst

Abstract: Threo cross-aldol products are predominantly formed in good yields by treating tert-butyldimethylsilyl enol ethers with aldehydes in the presence of a catalytic amount of trityl perchlorate.

Trityl salts as efficient catalysts in the aldol reaction

Abstract: In the presence of a catalytic amount of trityl salts, such as TrOTf, TrSbCl6, TrPF6, TrSnCl5, etc., silyl enol ethers react with aldehydes to give the corresponding aldols in good yields. The preferential formations of erythro or threo aldols become possible by the suitable choice of the counter anions of these trityl salts and the substituents on silicon of the enolates.

Trityl perchlorate as an efficient catalyst in the aldol-type reaction

Abstract: In the presence of a catalytic amount of trityl perchlorate, silyl enol ethers and ketene silyl acetals react with acetals and methyl orthoformate to give the corresponding aldol-type addition products in good yields.

Domino Reactions in Organic Synthesis

Abstract: Introduction Cationic domino reactions Anionic domino reactions Radical domino reactions Pericyclic domino reactions Photochemically induced domino processes Transition metal catalysis Domino reactions initiated by oxidation or reduction Enzymes in domino reactions Multicomponent reactions Special techniques in domino reactions

Amino Acid Catalyzed Direct Asymmetric Aldol Reactions: A Bioorganic Approach to Catalytic Asymmetric Carbon-Carbon Bond-Forming Reactions

Abstract: Direct asymmetric catalytic aldol reactions have been successfully performed using aldehydes and unmodified ketones together with commercially available chiral cyclic secondary amines as catalysts Structure-based catalyst screening identified l-proline and 5,5-dimethyl thiazolidinium-4-carboxylate (DMTC) as the most powerful amino acid catalysts for the reaction of both acyclic and cyclic ketones as aldol donors with aromatic and aliphatic aldehydes to afford the corresponding aldol products with high regio-, diastereo-, and enantioselectivities Reactions employing hydroxyacetone as an aldol donor provide anti-1,2-diols as the major product with ee values up to >99% The reactions are assumed to proceed via a metal-free Zimmerman−Traxler-type transition state and involve an enamine intermediate The observed stereochemistry of the products is in accordance with the proposed transition state Further supporting evidence is provided by the lack of nonlinear effects The reactions tolerate a small amount o

Rare-earth metal triflates in organic synthesis

Abstract: 2.1.8. Michael Reaction 2245 2.1.9. Others 2247 2.2. Cyclization Reactions 2248 2.2.1. Carbon Diels−Alder Reactions 2248 2.2.2. Aza-Diels−Alder Reactions 2252 2.2.3. Other Hetero-Diels−Alder Reactions 2255 2.2.4. Ionic Diels−Alder Reaction 2256 2.2.5. 1,3-Dipolar Cycloadditions 2256 2.2.6. Other Cycloaddition Reactions 2258 2.2.7. Prins-type Cyclization 2259 2.3. Friedel−Crafts Acylation and Alkylation 2259 2.4. Baylis−Hillman Reaction 2263 2.5. Radical Addition 2264 2.6. Heterocycle Synthesis 2267 2.7. Diazocarbonyl Insertion 2270 3. C−X (X ) N, O, P, Etc.) Bond Formation 2271 3.1. Aromatic Nitration and Sulfonylation 2271 3.2. Michael Reaction 2272 3.3. Glycosylation 2273 3.4. Aziridination 2275 3.5. Diazocarbonyl Insertion 2276 3.6. Ring-Opening Reactions 2277 3.7. Other C−X Bond Formations 2280 4. Oxidation and Reduction 2280 4.1. Oxidation 2280 4.2. Reduction 2281 5. Rearrangement 2283 6. Protection and Deprotection 2285 6.1. Protection 2285 6.2. Deprotection 2288 7. Polymerization 2291 8. Miscellaneous Reactions 2291 9. Lanthanide(II) Triflates in Organic Synthesis 2295 10. Conclusion 2295 11. Acknowledgment 2295 12. References 2295

Nitrogen-containing ligands for asymmetric homogeneous and heterogeneous catalysis.

Abstract: II.2.1. Homogeneous Systems 2166 II.2.2. Heterogeneous Systems 2168 II.3. Hydride Transfer Reduction 2169 II.3.1. Homogeneous Systems 2169 II.3.2. Heterogeneous Systems 2171 II.4. Hydrosilylation 2172 III. C−O Bond Formation 2173 III.1. Epoxidation of Unfunctionalized Olefins 2173 III.1.1. Homogeneous Catalysis 2173 III.1.2. Heterogeneous System 2176 III.2. Dihydroxylation of Olefins 2178 III.2.1. Homogeneous Systems 2178 III.2.2. Heterogeneous System 2178 III.3. Ring Opening of Meso Epoxides 2180 III.4. Kinetic Resolution 2180 III.4.1. Terminal Epoxides 2180 III.4.2. Secondary Alcohols 2181 IV. C−H Bond Oxidation 2181 IV.1. Allylic and Benzylic Oxidation 2181 IV.2. Baeyer−Villiger-type Reaction 2181 IV.3. Wacker-type Cyclization 2182 V. S−O Bond Formation 2182 VI. C−N Bond Formation 2183 VI.1. Hydroboration/Amination 2183 VI.2. Enolate Amination 2183 VI.3. Aza-Claisen Rearrangement 2183 VI.4. Azide Synthesis 2184 VI.5. Aminohydroxylation 2184 VI.6. Aziridine Synthesis 2184 VI.7. C−N Bond Formation via S−N Bond Formation 2185