“In situ immobilization” of a multicomponent chiral catalyst (MCC) via non-covalent interactions for heterogeneous asymmetric hydrogenation reactions

2020 ◽  
Vol 7 (2) ◽  
pp. 345-349
Author(s):  
Er-Jun Hao ◽  
Gong-Xin Li ◽  
Zhen-Zhen Lv ◽  
Fu-Sheng Li ◽  
Yu-Qing Chen ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Asymmetric Hydrogenation ◽  
Stacking Interactions ◽  
In Situ Immobilization ◽  
Chiral Catalyst ◽  
Hydrogenation Reactions ◽  
Non Covalent Interactions ◽  
Dehydroamino Acid ◽  
Covalent Interactions

Novel hybrid catalysts that resulted from the anchoring of pyrene-tagged Rh(i) complexes onto graphene materials via π–π stacking interactions show excellent catalytic activity towards the hydrogenation of dehydroamino acid.

Catalytic asymmetric hydrogenation reaction by in situ formed ultra-fine metal nanoparticles in live thermophilic hydrogen-producing bacteria

Nanoscale ◽  
2021 ◽  
Author(s):  
Wei Bing ◽  
Faming Wang ◽  
Yuhuan Sun ◽  
Jinsong Ren ◽  
Xiaogang Qu
Keyword(s):  
Metal Nanoparticles ◽  
Catalytic Hydrogenation ◽  
Asymmetric Hydrogenation ◽  
Environmentally Friendly ◽  
Hydrogenation Reaction ◽  
Highly Efficient ◽  
Hydrogenation Reactions ◽  
Live Bacteria ◽  
Catalytic Asymmetric Hydrogenation

An environmentally friendly biomimetic strategy has been presented and validated for the catalytic hydrogenation reaction in live bacteria. In situ formed ultra-fine metal nanoparticles can realize highly efficient asymmetric hydrogenation reactions.

scholarly journals Phosphorus Kβ X-Ray emission spectroscopy detects non-covalent interactions of phosphate biomolecules in situ

2021 ◽  
Author(s):  
Zachary Mathe ◽  
Olivia McCubbin Stepanic ◽  
Sergey Peredkov ◽  
Serena DeBeer
Keyword(s):  
Nucleic Acids ◽  
Emission Spectroscopy ◽  
Adenine Nucleotides ◽  
X Ray ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Phosphate Groups

Phosphorus is ubiquitous in biochemistry, found in the phosphate groups of nucleic acids and the energy-transferring system of adenine nucleotides (e.g. ATP). Kβ X-ray emission spectroscopy (XES) at phosphorus has...

Asymmetric hydrogenation in nanoreactors with encapsulated Rh-MonoPhos catalyst

2015 ◽  
Vol 17 (3) ◽  
pp. 1702-1709 ◽  
Author(s):  
Mingmei Zhong ◽  
Xiaoming Zhang ◽  
Yaopeng Zhao ◽  
Can Li ◽  
Qihua Yang
Keyword(s):  
Catalytic Activity ◽  
Asymmetric Hydrogenation ◽  
Hydrogenation Reactions ◽  
Multicomponent Catalyst

Encapsulated multicomponent catalyst, Rh-MonoPhos, in nanoreactors showed excellent catalytic activity in the asymmetric hydrogenation reactions.

Enantioselective Catalytic Methods for the Elaboration of Chiral Tetrahydro-β-carbolines and Related Scaffolds

Synthesis ◽  
2017 ◽  
Vol 49 (12) ◽  
pp. 2605-2620 ◽  
Author(s):  
Nicolas Glinsky-Olivier ◽  
Xavier Guinchard
Keyword(s):  
Kinetic Resolution ◽  
Asymmetric Reduction ◽  
Asymmetric Hydrogenation ◽  
Transfer Hydrogenation ◽  
Chiral Molecules ◽  
Chiral Phosphoric Acid ◽  
Hydrogenation Reactions ◽  
Synthetic Intermediates ◽  
Catalyzed Reactions

Tetrahydro-β-carbolines are important synthetic intermediates in the total synthesis of natural products and of compounds exhibiting strong bioactivities. Over the last decades, catalytic methods using chiral catalysts have been described for their synthesis. This review covers catalytic and enantioselective methods to access chiral tetrahydro-β-carbolines and their applications in the elaboration of complex chiral molecules.1 Introduction2 Asymmetric Reduction of Dihydro-β-carbolines2.1 Asymmetric Transfer Hydrogenation Reactions2.2 Asymmetric Hydrogenation Reactions2.3 Biocatalyzed Reduction of Dihydro-β-carbolines3 Organocatalyzed Pictet–Spengler Reactions3.1 Chiral Thiourea-Catalyzed Reactions3.2 Chiral Phosphoric Acid Catalyzed Reactions4 Pictet–Spengler Reactions of In Situ Generated Cyclic Iminiums5 Organocatalyzed Functionalization of Dihydro-β-carboliniums6 Organocatalyzed Alkylation of Tetrahydro-β-carbolines7 Biocatalyzed Dynamic Kinetic Resolution of Tetrahydro-β-carbolines8 Conclusion and Perspectives

scholarly journals A co-opted ISG15-USP18 binding mechanism normally reserved for deISGylation controls type I IFN signalling

2021 ◽  
Author(s):  
Andri Vasou ◽  
Katie Nightingale ◽  
Vladimira Cetkovska ◽  
Connor GG Bamford ◽  
Jelena Andrejeva ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Autoinflammatory Disease ◽  
Type I Interferon ◽  
Negative Regulator ◽  
Regulatory Function ◽  
Type I ◽  
Binding Mechanism ◽  
Tight Control ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Type I interferon (IFN) signalling induces the expression of several hundred IFN-stimulated genes that provide an unfavourable environment for viral replication. To prevent an overexuberant response and autoinflammatory disease, IFN signalling requires tight control. One critical regulator is the ubiquitin-like protein ISG15, evidenced by autoinflammatory disease in patients with inherited ISG15 deficiencies. Current models suggest that ISG15 stabilises USP18, a well-established negative regulator of IFN signalling. USP18 also functions as an ISG15-specific peptidase, however its catalytic activity is dispensable for controlling IFN signalling. Here, we show that the ISG15-dependent stabilisation of USP18 is necessary but not sufficient for regulation of IFN signalling and that USP18 requires non-covalent interactions with ISG15 to enhance its regulatory function. Intriguingly, this trait has been acquired through co-option of a binding mechanism normally reserved for deISGylation, identifying an unexpected new function for ISG15.

scholarly journals The intermolecular interactions in the aminonitromethylbenzenes

2011 ◽  
Vol 9 (1) ◽  
pp. 94-105 ◽  
Author(s):  
Rafal Kruszynski ◽  
Tomasz Sieranski
Keyword(s):  
Hydrogen Bonds ◽  
Lone Pair ◽  
Quantum Mechanical ◽  
Stacking Interactions ◽  
Quantum Mechanical Calculations ◽  
Charge Redistribution ◽  
Intermolecular Hydrogen Bonds ◽  
Non Covalent Interactions ◽  
The One ◽  
Covalent Interactions

AbstractThe intermolecular non-covalent interactions in aminonitromethylbenzenes namely 2-methyl-4-nitroaniline, 4-methyl-3-nitroaniline, 2-methyl-6-nitroaniline, 4-amino-2,6-dinitrotoluene, 2-methyl-5-nitroaniline, 4-methyl-2-nitroaniline, 2,3-dimethyl-6-nitroaniline, 4,5-dimethyl-2-nitroaniline and 2-methyl-3,5-dinitroaniline were studied by quantum mechanical calculations at RHF/311++G(3df,2p) and B3LYP/311++G(3df,2p) level of theory. The calculations prove that solely geometrical study of hydrogen bonding can be very misleading because not all short distances (classified as hydrogen bonds on the basis of interaction geometry) are bonding in character. For studied compounds interaction energy ranges from 0.23 kcal mol−1 to 5.59 kcal mol−1. The creation of intermolecular hydrogen bonds leads to charge redistribution in donors and acceptors. The Natural Bonding Orbitals analysis shows that hydrogen bonds are created by transfer of electron density from the lone pair orbitals of the H-bond acceptor to the antibonding molecular orbitals of the H-bond donor and Rydberg orbitals of the hydrogen atom. The stacking interactions are the interactions of delocalized molecular π-orbitals of the one molecule with delocalized antibonding molecular π-orbitals and the antibonding molecular σ-orbital created between the carbon atoms of the second aromatic ring and vice versa.

scholarly journals The Hydricity and Reactivity Relationship in [ FeFe ]-hydrogenases

2020 ◽  
Author(s):  
Jacob Artz ◽  
David Mulder ◽  
Michael Ratzloff ◽  
John Peters ◽  
Paul King
Keyword(s):  
Catalytic Activity ◽  
Transition Metal ◽  
Thermodynamic Properties ◽  
Chemical Reactivity ◽  
Chemical Compounds ◽  
Transition Metal Catalysts ◽  
Metal Cofactor ◽  
Non Covalent Interactions ◽  
Metal Cofactors ◽  
Covalent Interactions

Abstract Reactivity of transition metal catalysts is controlled by covalent and non-covalent interactions that tune thermodynamic properties including hydricity. Hydricity is critical to catalytic activity and for modulating the reduction or oxidation of chemical compounds. Likewise, enzymes can employ transition metal cofactors and use metal-hydride intermediates tuned by protein frameworks to selectively control reactivity. One example, the [FeFe]-hydrogenases, catalyze reversible H2 activation with H2 oxidation to H+ reduction ratios spanning ~107 in rate, offering a model to determine the extent that hydricity controls reactivity. To address this question, the hydricity of the catalytic H cluster of two [FeFe]-hydrogenases, CpI and CpII, were compared. We show that for CpI, the higher rates of H+ reduction correspond to a more hydridic H cluster, whereas CpII, which strongly favors H2 oxidation, has a less hydridic H cluster. The results demonstrate that enzymes manipulate metal cofactor hydricity to enable an extraordinary range of chemical reactivity.

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