Asymmetric Direct Aldol Reaction in Confined Space: Molecular Conformations of Organocatalyst Affect Chiral Induction

2019 ◽  
Vol 4 (45) ◽  
pp. 13210-13218 ◽  
Author(s):  
Hemanshu A. Patel ◽  
Akash Gutal ◽  
Suban K. Sahoo ◽  
Hemant P. Soni
Keyword(s):  
Aldol Reaction ◽  
Confined Space ◽  
Molecular Conformations ◽  
Chiral Induction ◽  
Direct Aldol Reaction

scholarly journals Simple and fast microwave-assisted ruthenium_catalyzed direct aldol reaction

2012 ◽  
Vol 1 (2) ◽  
pp. 91-94 ◽  
Author(s):  
Elahe Keshavarz ◽  
Khalil Tabatabaeian ◽  
Manouchehr Mamaghani ◽  
Nosrat O. Mahmoodi
Keyword(s):  
Aldol Reaction ◽  
Microwave Assisted ◽  
Direct Aldol Reaction

Organocatalytic Asymmetricsyn-Selective Direct Aldol Reaction in Ionic Liquid

2010 ◽  
Vol 39 (5) ◽  
pp. 490-492 ◽  
Author(s):  
Fui-Fong Yong ◽  
Chai-Yun Poh ◽  
Guan-Leong Chua ◽  
Yong-Chua Teo
Keyword(s):  
Ionic Liquid ◽  
Aldol Reaction ◽  
Direct Aldol Reaction

Alternating chiral selectivity of aldol reactions under the confined space of mesoporous silica

2015 ◽  
Vol 51 (96) ◽  
pp. 17116-17119 ◽  
Author(s):  
Chewei Yeh ◽  
Yan-Ru Sun ◽  
Shing-Jong Huang ◽  
Yeun-Min Tsai ◽  
Soofin Cheng
Keyword(s):  
Mesoporous Silica ◽  
Aldol Reaction ◽  
Recyclable Catalyst ◽  
Aldol Reactions ◽  
Water Medium ◽  
Confined Space ◽  
Asymmetric Aldol ◽  
Co Catalysts ◽  
Asymmetric Aldol Reaction ◽  
Chiral Selectivity

The chiral selectivities were altered and high diastereo- and enantio-selectivities of the products were obtained in water medium without adding acid co-catalysts when a primary–tertiary diamine catalyst was immobilized on mesoporous SBA-15 to form a recyclable catalyst for the direct asymmetric aldol reaction of cyclohexanone with p-nitrobenzaldehyde.

Highly enantioselective asymmetric direct aldol reaction catalyzed by amine-functionalized tridentate sulfinyl ligands

2011 ◽  
Vol 22 (12) ◽  
pp. 1325-1327 ◽  
Author(s):  
Michał Rachwalski ◽  
Stanisław Leśniak ◽  
Piotr Kiełbasiński
Keyword(s):  
Aldol Reaction ◽  
Direct Aldol Reaction ◽  
Amine Functionalized

Asymmetric Direct Aldol Reaction Catalysed byL-Prolinethioamides

2006 ◽  
Vol 2006 (17) ◽  
pp. 3864-3876 ◽  
Author(s):  
Dorota Gryko ◽  
Radosław Lipiński
Keyword(s):  
Aldol Reaction ◽  
Direct Aldol Reaction

Synthesis of 1,2-Diamine Bifunctional Catalysts for the Direct Aldol Reaction Through Probing the Remote Amide Hydrogen

2019 ◽  
Vol 6 (2) ◽  
pp. 171-176
Author(s):  
Rajasekhar Dodda ◽  
Sampak Samanta ◽  
Matthew Su ◽  
John Cong-Gui Zhao
Keyword(s):  
Hydrogen Bonding ◽  
Catalytic Activity ◽  
Aldol Reaction ◽  
Catalytic Efficiency ◽  
Aldol Reactions ◽  
Catalyst Loading ◽  
Bifunctional Catalysts ◽  
Amide Hydrogen ◽  
Highly Efficient ◽  
Direct Aldol Reaction

Background: While proline can catalyze the asymmetric direct aldol reactions, its catalytic activity and catalyst turnover are both low. To improve the catalytic efficiency, many prolinebased organocatalysts have been developed. In this regard, prolinamide-based bifunctional catalysts have been demonstrated by us and others to be highly efficient catalysts for the direct aldol reactions. Results: Using the β-acetamido- and β-tosylamidoprolinamide catalysts, the highly enantio- and diastereoselective direct aldol reactions between enolizable ketones and aldehydes were achieved (up to >99% ee, 98:2 dr). A low catalyst loading of only 2-5 mol % of the β-tosylamidoprolinamide catalyst was needed to obtain the desired aldol products in good to high yields and high stereoselectivities. Methods: By carefully adjusting the hydrogen bonding ability of the remote β-amide hydrogen of the 1,2-diamine-based prolinamide bifunctional catalysts, the catalytic activity and the asymmetric induction of these catalysts were significantly improved for the direct aldol reaction between aldehydes and enolizable ketones. Conclusion: Some highly efficient 1,2-diamine-based bifunctional prolinamide catalysts have been developed through probing the remote β-amide hydrogen for its hydrogen bonding capability. These catalysts are easy to synthesize and high enantioselectivities may be achieved at very low catalyst loadings.

scholarly journals Proline-coated gold nanoparticles as a highly efficient nanocatalyst for the enantioselective direct aldol reaction in water

RSC Advances ◽  
2013 ◽  
Vol 3 (12) ◽  
pp. 3861 ◽  
Author(s):  
Noureddine Khiar ◽  
Raquel Navas ◽  
Eleonora Elhalem ◽  
Victoria Valdivia ◽  
Inmaculada Fernández
Keyword(s):  
Gold Nanoparticles ◽  
Aldol Reaction ◽  
Highly Efficient ◽  
Direct Aldol Reaction ◽  
Reaction In Water
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