Molecular Engineering of β-Substituted Oxoporphyrinogens for Hydrogen-Bond Donor Catalysis

2019 ◽  
Author(s):  
Mandeep K. Chahal ◽  
Daniel Payne ◽  
Yoshitaka Matsushita ◽  
Jan Labuta ◽  
Katsuhiko Ariga ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Molecular Engineering ◽  
Hydrogen Bond Donor ◽  
Conjugate Additions ◽  
Bond Forming ◽  
Michael Additions ◽  
New Class ◽  
Hydrogen Bonding Interactions ◽  
Multiple Hydrogen Bond ◽  
Intramolecular Hydrogen

<p>A new class of bifunctional hydrogen-bond donor organocatalyst using oxoporphyrinogens with increased intramolecular hydrogen-bond donor distances is reported. Oxoporphyrinogens are highly non-planar rigid macrocycles containing a multiple hydrogen bond forming binding site. In this work we report the first example of non-planar OxPs as hydrogen-bond donor catalysts. The introduction of β-substituents is key to the catalytic activity and the catalysts are able to catalyze 1,4-conjugate additions and sulfa-Michael additions, as well as, Henry and aza-Henry reactions at low catalyst loadings (≤ 1 mol%) under mild conditions. Preliminary mechanistic studies have been carried out and a possible reaction mechanism has been proposed based on the bi-functional activation of both substrates through hydrogen-bonding interactions.</p>

Molecular Engineering of β-Substituted Oxoporphyrinogens for Hydrogen-Bond Donor Catalysis

2019 ◽  
Author(s):  
Mandeep K. Chahal ◽  
Daniel Payne ◽  
Yoshitaka Matsushita ◽  
Jan Labuta ◽  
Katsuhiko Ariga ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Molecular Engineering ◽  
Hydrogen Bond Donor ◽  
Conjugate Additions ◽  
Bond Forming ◽  
Michael Additions ◽  
New Class ◽  
Hydrogen Bonding Interactions ◽  
Multiple Hydrogen Bond ◽  
Intramolecular Hydrogen

<p>A new class of bifunctional hydrogen-bond donor organocatalyst using oxoporphyrinogens with increased intramolecular hydrogen-bond donor distances is reported. Oxoporphyrinogens are highly non-planar rigid macrocycles containing a multiple hydrogen bond forming binding site. In this work we report the first example of non-planar OxPs as hydrogen-bond donor catalysts. The introduction of β-substituents is key to the catalytic activity and the catalysts are able to catalyze 1,4-conjugate additions and sulfa-Michael additions, as well as, Henry and aza-Henry reactions at low catalyst loadings (≤ 1 mol%) under mild conditions. Preliminary mechanistic studies have been carried out and a possible reaction mechanism has been proposed based on the bi-functional activation of both substrates through hydrogen-bonding interactions.</p>

scholarly journals Facile and Promising Method for Michael Addition of Indole and Pyrrole to Electron-Deficienttrans-β-Nitroolefins Catalyzed by a Hydrogen Bond Donor Catalyst Feist’s Acid and Preliminary Study of Antimicrobial Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Abdullah M. A. Al Majid ◽  
Mohammad Shahidul Islam ◽  
Assem Barakat ◽  
Mohamed H. M. Al-Agamy ◽  
Mu. Naushad
Keyword(s):  
Antimicrobial Activity ◽  
Hydrogen Bond ◽  
Michael Addition ◽  
Hydrogen Bond Donor ◽  
New Class ◽  
Optimum Reaction ◽  
Preliminary Study ◽  
Cooperative Hydrogen Bonding ◽  
The Michael Addition

The importance of cooperative hydrogen-bonding effects has been demonstrated using novel 3-methylenecyclopropane-1,2-dicarboxylic acid (Feist’s acid (FA)) as hydrogen bond donor catalysts for the addition of indole and pyrrole totrans-β-nitrostyrene derivatives. Because of the hydrogen bond donor (HBD) ability, Feist’s acid (FA) has been introduced as a new class of hydrogen bond donor catalysts for the activation of nitroolefin towards nucleophilic substitution reaction. It has effectively catalyzed the Michael addition of indoles and pyrrole toβ-nitroolefins under optimum reaction condition to furnish the corresponding Michael adducts in good to excellent yields (up to 98%). The method is general, atom-economical, convenient, and eco-friendly and could provide excellent yields and regioselectivities. Some newly synthesized compounds were for examinedin vitroantimicrobial activity and their preliminary results are reported.

ChemInform Abstract: Silanediols: A New Class of Hydrogen Bond Donor Catalysts.

ChemInform ◽  
2012 ◽  
Vol 43 (6) ◽  
pp. no-no
Author(s):  
Andrew G. Schafer ◽  
Joshua M. Wieting ◽  
Anita E. Mattson
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bond Donor ◽  
New Class

Enantioselective Construction of Spirooxindole Derivatives through [3+2] Annulation Catalyzed by a Bisthiourea as a Multiple-Hydrogen-Bond Donor

2012 ◽  
Vol 19 (6) ◽  
pp. 1914-1918 ◽  
Author(s):  
Yan Shi ◽  
Aijun Lin ◽  
Haibin Mao ◽  
Zhijie Mao ◽  
Weipeng Li ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bond Donor ◽  
Multiple Hydrogen Bond

scholarly journals An Investigation of Five Component [3+2] Self-Assembled Cage Formation Using amidinium...carboxylate Hydrogen Bonds

2021 ◽  
Author(s):  
Chriso Thomas ◽  
Emer Foyle ◽  
Samuel Walker ◽  
Nicholas White
Keyword(s):  
Hydrogen Bond ◽  
Self Assembly ◽  
Solvent Mixtures ◽  
Hydrogen Bond Donor ◽  
Cage Structure ◽  
Hydrogen Bond Acceptor ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
The Individual ◽  
And Diffusion

The assembly of hydrogen bonded cages using amidinium∙∙∙carboxylate hydrogen bonding interactions was investigated. A new tris-amidinium hydrogen bond donor tecton based on a tetraphenylmethane scaffold was prepared and its self–assembly with the terephthalate anion studied, and a new tricarboxylate hydrogen bond acceptor tecton was synthesized and its assembly with the 1,3-benzenebis(amidinium) hydrogen bond donor explored. In both cases, molecular modelling indicated that the formation of the cages was geometrically feasible and 1H NMR spectroscopic evidence was consistent with interactions between the components in competitive d6- DMSO solvent mixtures. DOSY NMR spectroscopy of both systems indicated that both components diffuse at the same rate as each other, and diffusion coefficients were consistent with cage formation, and with the formation of assemblies significantly larger than the individual components. An X-ray crystal structure showed that one of the assemblies did not have the desired cage structure in the solid state

scholarly journals Crystal structure of trirubidium citrate monohydrate from laboratory X-ray powder diffraction data and DFT comparison

2017 ◽  
Vol 73 (2) ◽  
pp. 227-230 ◽  
Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Three Dimensional ◽  
Powder Diffraction Data ◽  
Hydrogen Bond Donor ◽  
X Ray ◽  
Intramolecular Hydrogen

The crystal structure of the title compound, 3Rb+·C6H5O73−·H2O, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The hydroxy group participates in an intramolecular hydrogen bond to the deprotonated central carboxylate group with graph-set motifS(5). The water molecule acts as a hydrogen-bond donor to both terminal and central carboxylate O atoms. The three independent rubidium cations are seven-, six- and six-coordinate, with bond-valence sums of 0.84, 1.02, and 0.95, respectively. In the extended structure, their polyhedra share edges and corners to form a three-dimensional network. The hydrophobic methylene groups occupy channels along thebaxis.

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