scholarly journals Chiral Thioureas—Preparation and Significance in Asymmetric Synthesis and Medicinal Chemistry

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 401 ◽  
Author(s):  
Franz Steppeler ◽  
Dominika Iwan ◽  
Elżbieta Wojaczyńska ◽  
Jacek Wojaczyński
Keyword(s):  
Hydrogen Bond ◽  
Drug Development ◽  
Asymmetric Synthesis ◽  
Stereoselective Synthesis ◽  
Strong Hydrogen Bond ◽  
Hydrogen Bond Donor ◽  
Drug Candidates ◽  
Current State ◽  
The Family ◽  
Donor Capability

For almost 20 years, thioureas have been experiencing a renaissance of interest with the emerged development of asymmetric organocatalysts. Due to their relatively high acidity and strong hydrogen bond donor capability, they differ significantly from ureas and offer, appropriately modified, great potential as organocatalysts, chelators, drug candidates, etc. The review focuses on the family of chiral thioureas, presenting an overview of the current state of knowledge on their synthesis and selected applications in stereoselective synthesis and drug development.

scholarly journals Novel amide-functionalized chloramphenicol base bifunctional organocatalysts for enantioselective alcoholysis of meso-cyclic anhydrides

2018 ◽  
Vol 14 ◽  
pp. 309-317 ◽  
Author(s):  
Lingjun Xu ◽  
Shuwen Han ◽  
Linjie Yan ◽  
Haifeng Wang ◽  
Haihui Peng ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Asymmetric Synthesis ◽  
Hydrogen Bond Donor ◽  
Cyclic Anhydrides ◽  
Enantioselective Alcoholysis

A family of novel chloramphenicol base-amide organocatalysts possessing a NH functionality at C-1 position as monodentate hydrogen bond donor were developed and evaluated for enantioselective organocatalytic alcoholysis of meso-cyclic anhydrides. These structural diversified organocatalysts were found to induce high enantioselectivity in alcoholysis of anhydrides and was successfully applied to the asymmetric synthesis of (S)-GABOB.

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.

scholarly journals Towards an understanding of the propensity for crystalline hydrate formation by molecular compounds

IUCrJ ◽  
2016 ◽  
Vol 3 (6) ◽  
pp. 430-439 ◽  
Author(s):  
Alankriti Bajpai ◽  
Hayley S. Scott ◽  
Tony Pham ◽  
Kai-Jie Chen ◽  
Brian Space ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Crystal Packing ◽  
Hydrate Formation ◽  
Crystalline Hydrate ◽  
Strong Hydrogen Bond ◽  
Hydrogen Bond Donor ◽  
Screening Experiments ◽  
Group Form ◽  
Structural Database ◽  
Molecular Compounds

Hydrates are technologically important and ubiquitous yet they remain a poorly understood and understudied class of molecular crystals. In this work, we attempt to rationalize propensity towards hydrate formation through crystallization studies of molecules that lack strong hydrogen-bond donor groups. A Cambridge Structural Database (CSD) survey indicates that the statistical occurrence of hydrates in 124 molecules that contain five- and six-memberedN-heterocyclic aromatic moieties is 18.5%. However, hydrate screening experiments on a library of 11N-heterocyclic aromatic compounds with at least two acceptor moieties and no competing hydrogen-bond donors or acceptors reveals that over 70% of this group form hydrates, suggesting that extrapolation from CSD statistics might, at least in some cases, be deceiving. Slurrying in water and exposure to humidity were found to be the most effective discovery methods. Electrostatic potential maps and/or analysis of the crystal packing in anhydrate structures was used to rationalize why certain molecules did not readily form hydrates.

Redox-Controlled Hydrogen Bonding: Turning a Superbase into a Strong Hydrogen-Bond Donor

2014 ◽  
Vol 20 (20) ◽  
pp. 5914-5925 ◽  
Author(s):  
Ute Wild ◽  
Christiane Neuhäuser ◽  
Sven Wiesner ◽  
Elisabeth Kaifer ◽  
Hubert Wadepohl ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Strong Hydrogen Bond ◽  
Hydrogen Bond Donor

A study of bacterial cellulose confined ionic liquid and deep eutectic solvent gel materials

2020 ◽  
Author(s):  
◽  
Chip Joseph II Smith
Keyword(s):  
Hydrogen Bond ◽  
Bacterial Cellulose ◽  
Carbon Capture ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Strong Hydrogen Bond ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
University Of Missouri ◽  
Analyte Detection

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI--COLUMBIA AT REQUEST OF AUTHOR.] Pollutants have become more prevalent in the air, water, and ground, necessitating the development of technologies that would help, limit, reverse, monitor, measure, and recycle prevalent pollutants. Ionic liquids (ILs), or molten salts that are liquid at or below 100[degrees]C, as well as deep eutectic solvents (DESs), a mixture of a hydrogen bond donor with a strong hydrogen bond acceptor that remains liquid upon cooling, have been popularized as greener alternatives in industry. These liquids tend to have large electrochemical and thermal windows, a very small vapor pressure, and can be fine-tuned for many applications. The liquid state of ILs and DESs makes them quite useful in their application but complicates their handling. Ionogels and eutectogels enable the liquid-like dynamics of these solvents while adding a pseudo-solid like character that makes for ease of handling. Herein, a new group of confined ILs and DESs within a cellulosic matrix called bacterial cellulose iono/eutecto gels are produced that are shown to be applicable to analyte detection and are studied for a better understanding of the dynamics within the gel. These intriguing gels are flexible, transparent, size-tuneable, shape-tuneable, amenable to incorporation of dyes or other functional material, and capable of confining 99 wt.% of a solvent with little leakage from the gel. These materials affect the crystallinity of cellulose little, while the liquid presents a diffusional change that stems from restructuring of the fluid. These gels are capable of detection of ammonia, hydrogen sulfide, and temperature. Given their properties, iono/eutecto gels offer use in applications, such as electrochemical devices, wound healing, drug delivery, and carbon capture/separation membranes.

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