ChemInform Abstract: HYDROGEN BONDING ABILITIES AND SELF-ASSOCIATION OF SOME POTENTIALLY BIFUNCTIONAL CATALYSTS. PART 2. MERCAPTOAZOLE DERIVATIVES

1977 ◽  
Vol 8 (37) ◽  
pp. no-no
Author(s):  
E. GENTRIC ◽  
J. LAURANSAN ◽  
C. ROUSSEL ◽  
J. METZGER
Keyword(s):  
Hydrogen Bonding ◽  
Bifunctional Catalysts ◽  
Self Association

Molecular Association of Hydrogen Bonding Solutes, o-, m-, and p-Cresol, in Carbon Tetrachloride

1974 ◽  
Vol 52 (4) ◽  
pp. 653-660 ◽  
Author(s):  
Earl M. Woolley ◽  
Dennis S. Rushforth
Keyword(s):  
Hydrogen Bonding ◽  
Carbon Tetrachloride ◽  
Least Squares ◽  
Molecular Association ◽  
Intermolecular Hydrogen Bonding ◽  
Heats Of Dilution ◽  
Self Association

The intermolecular hydrogen-bonding self-association of the three cresols in CCl4 solutions at 25 °C has been investigated by calorimetric means. Calorimetrically determined heats of dilution of each of the cresols in anhydrous CCl4 are interpreted in terms of two different models: (i) dimerization and trimerization self-association reactions, and (ii) dimerization followed by stepwise polymerization self-association reactions. Values of K, ΔH0, and ΔS0 for these reactions are calculated using least-squares and other methods. Results show that o-cresol is clearly less associated in anhydrous CCl4 solution at 25 °C than either m- or p-cresol. Values of K2 and K3 (both based on molar concentrations of solutes) and ΔH20and ΔH30 (kcal) for the reactions [Formula: see text] respectively, are o-cresol: 0.7, 1.3,−3.4,−12.5; m-cresol: 0.8, 5.0,−5.0,−13.6; p-cresol: 0.35, 6.5,−5.5,−13.4. Values of K2 and Ks (both based on molar concentrations of solutes) and ΔH20 and ΔHs0 (kcal) for the reactions [Formula: see text] (all n > 2 with same Ks and ΔHS0), respectively, are o-cresol: 0.7, 1.6, −4.2, −4.5; m-cresol: 1.2, 4.0, −5.0, −4.3; p-cresol: 1.0, 7.0, −3.3, −3.5.

scholarly journals Synthesis and self-association of dibenzothiophene derivatives for simulation of hydrogen bonding interaction in asphaltenes

2015 ◽  
Vol 12 (3) ◽  
pp. 501-508
Author(s):  
Ying-Hui Bian ◽  
Shao-Tang Xu ◽  
Le-Chun Song ◽  
Yu-Lu Zhou ◽  
Li-Jun Zhu ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonding Interaction ◽  
Bonding Interaction ◽  
Self Association

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.

Novel ferrocene-based bifunctional amine–thioureas for asymmetric Michael addition of acetylacetone to nitroolefins

2015 ◽  
Vol 13 (17) ◽  
pp. 5054-5060 ◽  
Author(s):  
Xiaochen Ren ◽  
Chunyan He ◽  
Yingle Feng ◽  
Yonghai Chai ◽  
Wei Yao ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Efficient Method ◽  
Michael Addition ◽  
High Yield ◽  
Bifunctional Catalysts ◽  
Michael Adducts ◽  
Asymmetric Michael Addition ◽  
Multiple Hydrogen Bonding

An efficient method was developed to synthesize the ferrocene-based bifunctional amine–thioureas bearing multiple hydrogen-bonding donors. Asymmetric Michael addition of acetylacetone to nitroolefins catalyzed by these novel bifunctional catalysts affords the Michael adducts in high yield and moderate to excellent enantioselectivities.

Sign in / Sign up

Export Citation Format

Share Document