scholarly journals Isocyanide Multicomponent Reactions on Solid Phase: State of the Art and Future Application

2020 ◽  
Vol 21 (23) ◽  
pp. 9160
Author(s):  
Naděžda Cankařová ◽  
Viktor Krchňák
Keyword(s):  
Small Molecules ◽  
Multicomponent Reactions ◽  
Organic Molecules ◽  
Phase State ◽  
State Of The Art ◽  
Solid Phase ◽  
Structural Diversity ◽  
Future Application ◽  
Chemical Transformations ◽  
Chemical Libraries

Drug discovery efforts largely depend on access to structural diversity. Multicomponent reactions allow for time-efficient chemical transformations and provide advanced intermediates with three or four points of diversification for further expansion to a structural variety of organic molecules. This review is aimed at solid-phase syntheses of small molecules involving isocyanide-based multicomponent reactions. The majority of all reported syntheses employ the Ugi four-component reaction. The review also covers the Passerini and Groebke-Blackburn-Bienaymé reactions. To date, the main advantages of the solid-phase approach are the ability to prepare chemical libraries intended for biological screening and elimination of the isocyanide odor. However, the potential of multicomponent reactions has not been fully exploited. The unexplored avenues of these reactions, including chiral frameworks, DNA-encoded libraries, eco-friendly synthesis, and chiral auxiliary reactions, are briefly outlined.

An Overview on Steroids and Microwave Energy in Multi-Component Reactions towards the Synthesis of Novel Hybrid Molecules

2020 ◽  
Vol 17 (8) ◽  
pp. 594-609
Author(s):  
Preetismita Borah ◽  
Vhatkar Dattatraya Shivling ◽  
Bimal Krishna Banik ◽  
Biswa Mohan Sahoo
Keyword(s):  
Energy Consumption ◽  
Multicomponent Reactions ◽  
Biological Activities ◽  
Vital Role ◽  
Microwave Energy ◽  
Biosynthetic Pathways ◽  
Chemical Transformations ◽  
Carbon Carbon Bond ◽  
Hybrid Molecules ◽  
Time Required

In recent years, hybrid systems are gaining considerable attention owing to their various biological applications in drug development. Generally, hybrid molecules are constructed from different molecular entities to generate a new functional molecule with improved biological activities. There already exist a large number of naturally occurring hybrid molecules based on both non-steroid and steroid frameworks synthesized by nature through mixed biosynthetic pathways such as, a) integration of the different biosynthetic pathways or b) Carbon- Carbon bond formation between different components derived through different biosynthetic pathways. Multicomponent reactions are a great way to generate efficient libraries of hybrid compounds with high diversity. Throughout the scientific history, the most common factors developing technologies are less energy consumption and avoiding the use of hazardous reagents. In this case, microwave energy plays a vital role in chemical transformations since it involves two very essential criteria of synthesis, minimizing energy consumption required for heating and time required for the reaction. This review summarizes the use of microwave energy in the synthesis of steroidal and non-steroidal hybrid molecules and the use of multicomponent reactions.

scholarly journals Formation of a Low-Density Liquid Phase during the Dissociation of Gas Hydrates in Confined Environments

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 590
Author(s):  
Lihua Wan ◽  
Xiaoya Zang ◽  
Juan Fu ◽  
Xuebing Zhou ◽  
Jingsheng Lu ◽  
...  
Keyword(s):  
Natural Gas ◽  
Methane Hydrate ◽  
Phase State ◽  
Solid Phase ◽  
Potential Method ◽  
Methane Hydrates ◽  
Low Density ◽  
Hydrate Dissociation ◽  
State Of Water ◽  
Confined Environment

The large amounts of natural gas in a dense solid phase stored in the confined environment of porous materials have become a new, potential method for storing and transporting natural gas. However, there is no experimental evidence to accurately determine the phase state of water during nanoscale gas hydrate dissociation. The results on the dissociation behavior of methane hydrates confined in a nanosilica gel and the contained water phase state during hydrate dissociation at temperatures below the ice point and under atmospheric pressure are presented. Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD) were used to trace the dissociation of confined methane hydrate synthesized from pore water confined inside the nanosilica gel. The characterization of the confined methane hydrate was also analyzed by PXRD. It was found that the confined methane hydrates dissociated into ultra viscous low-density liquid water (LDL) and methane gas. The results showed that the mechanism of confined methane hydrate dissociation at temperatures below the ice point depended on the phase state of water during hydrate dissociation.

Examination of Aggregation Induced Enhanced Emission in a Propeller Shaped Chiral- Nonconjugated Blue Emitter from Restricted Intramolecular Rotation and J Type π⋯π Stacking Interactions

2021 ◽  
Author(s):  
Gul Yakali
Keyword(s):  
Thin Film ◽  
Small Molecules ◽  
Solid Phase ◽  
Stacking Interactions ◽  
Optoelectronic Materials ◽  
Π Stacking ◽  
Intramolecular Rotation

Fluorescent organic small molecules with the property of aggregation induced enhanced emission in the solid phase (crystall or thin film) have great attention for the design of optoelectronic materials. Generally,...

scholarly journals The Chemical Composition of Cometary Nuclei

1972 ◽  
Vol 45 ◽  
pp. 265-270
Author(s):  
L. M. Shul'man
Keyword(s):  
Chemical Composition ◽  
Cosmic Rays ◽  
Organic Molecules ◽  
Solid Phase ◽  
Critical Concentration ◽  
Energy Output ◽  
Time Interval ◽  
Nuclear Surface ◽  
Solar Cosmic Rays ◽  
Cometary Nuclei

The probable parent-molecules of radicals such as C3 and N2+ are discussed, and it is concluded that cometary nuclei may contain complicated organic molecules, such as C3H4, CH2N2, and C4H2. It is suggested that these molecules are formed by radiation synthesis in solid phase. In a time interval of order 107 to 109 yr bombardment from cosmic rays would be expected to transform the chemical composition to a depth of 1 m. Solar cosmic rays do not penetrate as far, and as a result the surface layer of the nucleus can be enriched with unsaturated hydrocarbons. After a critical concentration of this explosive material is reached a further burst of solar cosmic rays can initiate an explosion and thus an outburst in the comet's brightness. This mechanism is the only one advanced to date that can explain the synchronism of the energy output over the whole nuclear surface.

Heat Transfer Characteristics of the Phase Change Material Microcapsule Slurry in Solid Phase State

2011 ◽  
Vol 71-78 ◽  
pp. 1187-1190
Author(s):  
Yan Lai Zhang ◽  
Zhong Hao Rao ◽  
Shuang Feng Wang ◽  
Hong Zhang ◽  
Li Jun Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Rayleigh Number ◽  
Aspect Ratio ◽  
Phase State ◽  
Solid Phase ◽  
Heat Transfer Characteristics ◽  
Rectangular Enclosure ◽  
Transfer Characteristics ◽  
Change Material

This experiment is performed to investigate heat transfer characteristics with the PCM microcapsule slurry in a solid phase state at a horizontal rectangular enclosure heating from below and cooling from top. Some important parameters are taken into account such as the mass concentration of the PCM, the temperature difference between heating plate and cooling plate, Nusselt number Nu, Rayleigh number Ra and the aspect ratio (width/height) of the horizontal rectangular enclosure. Experiment is done under the thermal steady condition in the PCM microcapsule slurry. Heat transfer coefficient is measured under various temperature differences in PCM mass concentrations of 10% and 20%. And relationship with Nusselt number Nu and Rayleigh number Ra is summarized to various heights H or the aspect ratio (width/height) Ar of enclosure.

scholarly journals Correlations between retention volume and molecular size parameters in gel permeation chromatography of small molecules

1975 ◽  
Vol 28 (1) ◽  
pp. 189 ◽  
Author(s):  
RA Shanks
Keyword(s):  
Molecular Weight ◽  
Small Molecules ◽  
Organic Molecules ◽  
Retention Volume ◽  
Molecular Size ◽  
Gel Permeation Chromatography ◽  
Molar Volumes ◽  
Small Organic Molecules ◽  
Molecular Dimension ◽  
Gel Permeation

Gel permeation columns of Bio Beads S-X8 have been used to provide separation of oligomers and other small organic molecules. Results show successful separations up to molecular weight c. 600. The retention times of compounds have been correlated with the largest molecular dimension of the molecules and also with molar volumes.

scholarly journals An Amphiphilic Polymer-Supported Strategy Enables Chemical Transformations Under Anhydrous Conditions for DNA-Encoded Library Synthesis

2019 ◽  
Author(s):  
Yves Ruff ◽  
Roberto Martinez ◽  
Xavier Pellé ◽  
Pierre Nimsgern ◽  
Pascale Fille ◽  
...  
Keyword(s):  
Small Molecules ◽  
Organic Solvents ◽  
Cross Coupling ◽  
Amphiphilic Polymer ◽  
Aryl Halides ◽  
Chemical Transformations ◽  
Library Synthesis ◽  
Catch And Release ◽  
Dna Conjugates ◽  
Polymer Supported

Herein, we describe the development of a practical catch-and release methodology utilizing a cationic, amphiphilic PEG-based polymer to perform chemical transformations on immobilized DNA conjugates under anhydrous conditions. We demonstrate the usefulness of our APTAC (<u>a</u>mphiphilic <u>p</u>olymer-facilitated <u>t</u>ransformations under <u>a</u>nhydrous <u>c</u>onditions) approach by performing several challenging transformations on DNA-conjugated small molecules in pure organic solvents: the addition of a carbanion equivalent to a DNA-conjugated ketone in tetrahydrofuran, the synthesis of saturated heterocycles using the tin (Sn) amine protocol (SnAP) in dichloromethane and the dual-catalytic (Ir/Ni) metallaphotoredox decarboxylative cross-coupling of carboxylic acids to DNA-conjugated aryl halides in DMSO. In addition, we demonstrate the feasibility of the latter in multititer-plate format.

scholarly journals RECENTES AVANÇOS NA FUNCIONALIZAÇÃO SELETIVA DE QUINOLINAS

Química Nova ◽  
2021 ◽  
Author(s):  
Dartagnan Ferreira ◽  
Valter Murie ◽  
Thiago Santos ◽  
Paulo Vieira ◽  
Giuliano Clososki
Keyword(s):  
Wide Spectrum ◽  
Structural Diversity ◽  
Biological Properties ◽  
Biologically Active ◽  
Chemical Transformations ◽  
Heterocyclic Molecules ◽  
Point Of Interest ◽  
Selective Functionalization ◽  
Biological Interest ◽  
Approved Drugs

RECENT ADVANCES IN SELECTIVE FUNCTIONALIZATION OF QUINOLINES. Heterocyclic compounds form an important and extensive group of organic substances. Among nitrogenous heterocyclic molecules, quinolines stand out for exhibiting attractive chemical and biological properties. These substances can be used as ligands, sensors, luminescent and agrochemical materials. In addition, quinoline-containing compounds can exhibit a wide spectrum of pharmacological properties, allowing their use in several approved drugs nowadays. Due to its importance, the synthesis of molecules containing this nucleus becomes a point of interest for synthetic chemists. In this way, several methodologies have been recently developed to prepare quinoline derivatives with high structural diversity. Such chemical transformations allow the chemical modification of these rings with high selectivity and tolerance to diverse functional groups and these properties have been conveniently used in the preparation of biologically active molecules containing this unit. Herein, we present a review of the main methodologies employed in the selective functionalization of quinolines in the last twenty years. In this context, a brief introduction addressing general synthetic and medicinal aspects related to the functionalization positions of the quinoline ring is presented. Several methodologies used in the functionalization of this moiety are discussed, as well relevant synthetic applications, both in the preparation and functionalization of substances of biological interest.

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