scholarly journals New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

2016 ◽  
Vol 12 ◽  
pp. 2834-2848 ◽  
Author(s):  
Pavel Nagorny ◽  
Zhankui Sun
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Recent Progress ◽  
Halogen Bonds ◽  
Hydrogen Bond Donor ◽  
New Approaches ◽  
Substrate Activation ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Hydrogen Bond Donors

Hydrogen bond donor catalysis represents a rapidly growing subfield of organocatalysis. While traditional hydrogen bond donors containing N–H and O–H moieties have been effectively used for electrophile activation, activation based on other types of non-covalent interactions is less common. This mini review highlights recent progress in developing and exploring new organic catalysts for electrophile activation through the formation of C–H hydrogen bonds and C–X halogen bonds.

scholarly journals Chain stopper engineering for hydrogen bonded supramolecular polymers

2010 ◽  
Vol 6 ◽  
pp. 869-875 ◽  
Author(s):  
Thomas Pinault ◽  
Bruno Andrioletti ◽  
Laurent Bouteiller
Keyword(s):  
Hydrogen Bond ◽  
Molar Mass ◽  
Strong Hydrogen Bond ◽  
Supramolecular Polymers ◽  
Supramolecular Polymer ◽  
Hydrogen Bond Donor ◽  
Linear Chains ◽  
Non Covalent Interactions ◽  
Viscous Solutions ◽  
Covalent Interactions

Supramolecular polymers are linear chains of low molar mass monomers held together by reversible and directional non-covalent interactions, which can form gels or highly viscous solutions if the self-assembled chains are sufficiently long and rigid. The viscosity of these solutions can be controlled by adding monofunctional compounds, which interact with the chain extremities: chain stoppers. We have synthesized new substituted ureas and thioureas and tested them as chain stoppers for a bis-urea based supramolecular polymer. In particular, the bis-thiourea analogue of the bis-urea monomer is shown not to form a supramolecular polymer, but a good chain stopper, because it is a strong hydrogen bond donor and a weak acceptor. Moreover, all substituted ureas tested reduce the viscosity of the supramolecular polymer solutions, but the best chain stopper is obtained when two hydrogen bond acceptors are placed in the same relative position as for the monomer and when no hydrogen bond donor is present.

Competition between hydrogen bonds and halogen bonds: a structural study

2018 ◽  
Vol 42 (13) ◽  
pp. 10539-10547 ◽  
Author(s):  
Janaka C. Gamekkanda ◽  
Abhijeet S. Sinha ◽  
John Desper ◽  
Marijana Đaković ◽  
Christer B. Aakeröy
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Structural Study ◽  
Halogen Bond ◽  
Halogen Bonds ◽  
Hydrogen Bond Donors

O–H hydrogen-bond donors and R–CC–I halogen-bond donors are close competitors for suitable acceptor sites in solid-state assembly.

Non-covalent interactions in molecular systems: thermodynamic evaluation of the hydrogen bond strength in aminoalcohols

2021 ◽  
Author(s):  
Riko Siewert ◽  
Ralf Ludwig ◽  
Sergey P. Verevkin
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Bond Strength ◽  
Functional Groups ◽  
Thermodynamic Evaluation ◽  
Molecular Systems ◽  
Hydrogen Bond Strength ◽  
Non Covalent Interactions ◽  
Intramolecular Hydrogen ◽  
Covalent Interactions

In molecules with two functional groups that form hydrogen bonds, the strength of intramolecular hydrogen bonds does not depend significantly on the structure.

6,9-Dibromo-2a,10b-diphenyl-2a,5,10,10b-tetrahydro-2H,3H-2,3,4a,10a-tetraazabenzo[g]cyclopenta[cd]azulene-1,4-dione monohydrate

2006 ◽  
Vol 62 (5) ◽  
pp. o1754-o1755
Author(s):  
Neng-Fang She ◽  
Sheng-Li Hu ◽  
Hui-Zhen Guo ◽  
An-Xin Wu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Title Compound ◽  
Supramolecular Structure ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Compound C ◽  
Bifurcated Hydrogen Bond

The title compound, C24H18Br2N4O2·H2O, forms a supramolecular structure via N—H...O, O—H...O and C—H...O hydrogen bonds. In the crystal structure, the water molecule serves as a bifurcated hydrogen-bond acceptor and as a hydrogen-bond donor.

Secondary Interactions in Gold(I) Complexes with Thione Ligands, 3. Three Ionic Dimesylamides [1, 2]

2004 ◽  
Vol 59 (11-12) ◽  
pp. 1429-1437 ◽  
Author(s):  
Friedrichsa Friedrichsa ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Layer Structure ◽  
Chain Structure ◽  
Hydrogen Bond Donor ◽  
Weak Hydrogen Bonds ◽  
Ribbon Structure ◽  
A Chain ◽  
Aurophilic Interactions ◽  
Short Contacts

Three structures of the form bis(thione)gold(I) di(methanesulfonyl)amide [thione = imidazolidine- 2-thione, 1; 1-methyl-imidazolidine-2-thione, 2; thiazolidine-2-thione, 3] were determined; all crystallize with one formula unit in the asymmetric unit. Each N-H hydrogen bond donor forms one classical two-centre hydrogen bond with an anion acceptor. Compound 1 thereby forms a complex layer structure with a layer thickness of 10.17 Å ; the packing may be analysed in terms of thinner subunit layers consisting of interlinked, hydrogen-bonded chains and rings. Compound 2 forms a chain structure consisting of a series of “hairpin bends”, a common feature in the gold complexes of 1-alkyl-imidazolidine-2-thiones. Compound 3 forms a corrugated ribbon structure in which the central region consists of parallel S-Au-S axes linked by aurophilic interactions; the anions exercise a “clamping” function by forming hydrogen bonds at the periphery of the ribbons. Further short contacts can be classed as weak hydrogen bonds C-H ··· X, with X = N, O, S or Au.

Selective encapsulation and extraction of hydrogenphosphate by a hydrogen bond donor tripodal receptor

CrystEngComm ◽  
2020 ◽  
Vol 22 (37) ◽  
pp. 6152-6160
Author(s):  
Sandeep Kumar Dey ◽  
Archana ◽  
Sybil Pereira ◽  
Sarvesh S. Harmalkar ◽  
Shashank N. Mhaldar ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Hydrogen Bond Donor ◽  
Tripodal Receptor ◽  
Multiple Hydrogen Bonds

Intramolecular N–H⋯OC hydrogen bonding between the inner amide groups dictates the receptor–anion complementarity in a tripodal receptor towards selective encapsulation of hydrogenphosphate in the outer urea cavity by multiple hydrogen bonds.

Solid-State NMR at the University of Ottawa

2015 ◽  
Vol 93 (5) ◽  
pp. 485-491
Author(s):  
David L. Bryce
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Materials Characterization ◽  
Canadian Society ◽  
Halogen Bonds ◽  
Biomolecular Nmr ◽  
Non Covalent Interactions ◽  
Nmr Crystallography ◽  
The University ◽  
Covalent Interactions

This article describes some highlights of the research which has been carried out in my laboratory at the University of Ottawa over the period covering 2005 to 2014. My research is in the general areas of solid-state NMR, applications of quantum chemistry, and biomolecular NMR. The format will follow that of my 2014 Canadian Society for Chemistry Keith Laidler Award presentation given in Vancouver in June 2014 at the 97th Canadian Chemistry Conference and Exhibition. Following a brief introduction, I will present some of our most interesting and exciting recent advances according to the following six themes: 1. Fundamental solid-state NMR. 2. Materials characterization and NMR crystallography. 3. Pharmaceuticals and polymorphism. 4. Non-covalent interactions: Halogen bonds. 5. Biomolecular NMR. 6. Software development.

Direct Immobilization of Ru-Based Catalysts on Silica: Hydrogen Bonds as Non-Covalent Interactions for Recycling in Metathesis Reactions

ChemCatChem ◽  
2015 ◽  
Vol 7 (16) ◽  
pp. 2493-2500 ◽  
Author(s):  
Houssein Nasrallah ◽  
Diana Dragoe ◽  
Caroline Magnier ◽  
Christophe Crévisy ◽  
Marc Mauduit ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Metathesis Reactions ◽  
Non Covalent Interactions ◽  
Direct Immobilization ◽  
Covalent Interactions
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