scholarly journals On the Search of a Silver Bullet for the Preparation of Bioinspired Molecular Electrets with Propensity to Transfer Holes at High Potentials

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 429
Author(s):  
James Bennett Derr ◽  
Katarzyna Rybicka-Jasińska ◽  
Eli Misael Espinoza ◽  
Maryann Morales ◽  
Mimi Karen Billones ◽  
...  
Keyword(s):  
Free Acid ◽  
Building Blocks ◽  
Butyl Ether ◽  
One Pot ◽  
Nitrobenzoic Acid ◽  
Wide Range ◽  
High Potentials ◽  
Scalable Synthesis ◽  
High Yields ◽  
Derivatives Of

Biological structure-function relationships offer incomparable paradigms for charge-transfer (CT) science and its implementation in solar-energy engineering, organic electronics, and photonics. Electrets are systems with co-directionally oriented electric dopes with immense importance for CT science, and bioinspired molecular electrets are polyamides of anthranilic-acid derivatives with designs originating from natural biomolecular motifs. This publication focuses on the synthesis of molecular electrets with ether substituents. As important as ether electret residues are for transferring holes under relatively high potentials, the synthesis of their precursors presents formidable challenges. Each residue in the molecular electrets is introduced as its 2-nitrobenzoic acid (NBA) derivative. Hence, robust and scalable synthesis of ether derivatives of NBA is essential for making such hole-transfer molecular electrets. Purdie-Irvine alkylation, using silver oxide, produces with 90% yield the esters of the NBA building block for iso-butyl ether electrets. It warrants additional ester hydrolysis for obtaining the desired NBA precursor. Conversely, Williamson etherification selectively produces the same free-acid ether derivative in one-pot reaction, but a 40% yield. The high yields of Purdie-Irvine alkylation and the selectivity of the Williamson etherification provide important guidelines for synthesizing building blocks for bioinspired molecular electrets and a wide range of other complex ether conjugates.

Stereospecific, Palladium-catalyzed C(sp3)–H Alkenylation and Alkynylation of a Proline Derivative Enabled by 8-Aminoquinoline as a Directing Group

2020 ◽  
Author(s):  
Aleksandra Balliu ◽  
Aaltje Roelofje Femmigje Strijker ◽  
Michael Oschmann ◽  
Monireh Pourghasemi Lati ◽  
Oscar Verho
Keyword(s):  
Carboxylic Acid ◽  
Building Blocks ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
High Yields ◽  
Vinyl Iodides ◽  
Initial Results

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>

scholarly journals Thioesters Provide a Robust Path to Prebiotic Peptides

2021 ◽  
Author(s):  
Moran Frenkel-Pinter ◽  
Marcos Bouza ◽  
Facundo M. Fernández ◽  
Luke J. Leman ◽  
Loren Dean Williams ◽  
...  
Keyword(s):  
Building Blocks ◽  
Peptide Bond ◽  
Side Reactions ◽  
Peptide Bond Formation ◽  
One Pot ◽  
Complex Molecules ◽  
Peptide Formation ◽  
Wide Range ◽  
Amide Exchange ◽  
Prebiotic Earth

The condensation of building blocks into oligomers and polymers was an early and important stage in the origins of life. High activation energies, unfavorable thermodynamics and side reactions are bottlenecks for abiotic formation of peptides. Thioesters are hypothesized to have played key roles in prebiotic chemistry on early Earth, serving as energy storing molecules, as synthetic intermediates, and as catalysts in the formation of more complex molecules, including polypeptides. However, all abiotic reactions reported thus far for peptide formation via thioester intermediates have relied on activated building blocks or condensing agents, which are of questionable prebiotic relevance. We report robust, plausible prebiotic reactions of mercaptoacids with amino acids that result in the formation of peptides and thiodepsipeptides, which contain both peptide and thioester bonds. Peptide bond formation proceeds by the condensation of mercaptoacids to form thioesters followed by thioester-amide exchange. Mercaptoacids catalyze thiodepsipeptides and peptide formation under a wide range of pH conditions and at mild temperatures. Our results offer the most robust one-pot pathway for peptide formation ever reported. These results support the hypothesis that thiodepsipeptides formed robustly on prebiotic Earth and were possible contributors to early chemical evolution.

scholarly journals A novel three-component reaction between isocyanides, alcohols or thiols and elemental sulfur: a mild, catalyst-free approach towards O-thiocarbamates and dithiocarbamates

2019 ◽  
Vol 15 ◽  
pp. 1523-1533 ◽  
Author(s):  
András György Németh ◽  
György Miklós Keserű ◽  
Péter Ábrányi-Balogh
Keyword(s):  
Elemental Sulfur ◽  
Building Blocks ◽  
Reaction Conditions ◽  
One Pot ◽  
Catalyst Free ◽  
Synthetic Procedure ◽  
Three Component Reaction ◽  
Wide Range ◽  
Organic Chemist ◽  
The One

A new multicomponent reaction has been developed between isocyanides, sulfur and alcohols or thiols under mild reaction conditions to afford O-thiocarbamates and dithiocarbamates in moderate to good yields. The one-pot reaction cascade involves the formation of an isothiocyanate intermediate, thus a catalyst-free synthesis of isothiocyanates, as valuable building blocks from isocyanides and sulfur is proposed, as well. The synthetic procedure suits the demand of a modern organic chemist, as it tolerates a wide range of functional groups, it is atom economic and easily scalable.

A Green Approach for the Synthesis of Novel 7,11-Dihydro-6H-chromeno[3,4-e]isoxazolo[5,4-b]pyridin-6-one Derivatives Using Acidic Ionic Liquid [C4mim][HSO4]

2016 ◽  
Vol 69 (9) ◽  
pp. 1049 ◽  
Author(s):  
Sudesh Kumari ◽  
M. Rajeswari ◽  
Jitender M. Khurana
Keyword(s):  
Ionic Liquid ◽  
Crystal Packing ◽  
Aromatic Aldehydes ◽  
Green Solvent ◽  
One Pot ◽  
X Ray ◽  
Acidic Ionic Liquid ◽  
Green Approach ◽  
Wide Range ◽  
High Yields

A multicomponent reaction capable of affording a wide range of novel 7,11-dihydro-6H-chromeno[3,4-e]isoxazolo[5,4-b]pyridin-6-one derivatives via one-pot three-component condensation of 4-hydroxycoumarin, aromatic aldehydes, and 5-amino-3-methylisoxazole in ionic liquid 1-butyl-3-methylimidazolium hydrogen sulfate ([C4mim][HSO4]) is reported. Structures have been confirmed by spectral and X-ray studies. Crystal packing of 4b has also been reported. Green solvent, short reaction time, easy workup, and high yields are the salient features of the present protocol.

Zirconium-Catalyzed Alkyne Carbo- and Cycloalumination Reactions in Stereoselective Preparation of 1-Alkenyl Selenides

Synthesis ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 4523-4534 ◽  
Author(s):  
Rita Kadikova ◽  
Ilfir Ramazanov ◽  
Alexey Vyatkin ◽  
Usein Dzhemilev
Keyword(s):  
One Pot ◽  
Versatile Tool ◽  
High Yields ◽  
Derivatives Of

The Cp2ZrCl2-catalyzed methylalumination and сycloalumination of 1-alkynyl selenides followed by deuterolysis or hydrolysis affords corresponding (Z)-1-alkenyl selenides in high yields. Alternatively, (E)-1-alkenyl selenides were prepared by the reaction of 1-alkenylaluminums with organic diselenides in a one-pot procedure starting from the corresponding 1-alkynes, which provides a versatile tool for the preparation of stereo-defined unsaturated organic derivatives of selenium.

Additive- and Oxidant-Free Expedient Synthesis of Benzimidazoles Catalyzed by Cobalt Nanocomposites on N-Doped Carbon

Synlett ◽  
2019 ◽  
Vol 30 (03) ◽  
pp. 319-324 ◽  
Author(s):  
Zhaozhan Wang ◽  
Tao Song ◽  
Yong Yang
Keyword(s):  
Functional Group ◽  
Direct Synthesis ◽  
Biologically Active ◽  
One Pot ◽  
Mild Conditions ◽  
Wide Range ◽  
High Yields

A one-pot direct synthesis of a wide range of biologically active benzimidazoles through coupling of phenylenediamines and aldehydes catalyzed by a highly recyclable nonnoble cobalt nanocomposite was developed. A broad set of benzimidazoles can be efficiently synthesized in high yields and with good functional-group tolerance under additive- and oxidant-free mild conditions. The catalyst can be easily recycled for successive uses, and the process permits gram-scale syntheses of benzimidazoles.

Multi-Component One Pot assisted Synthesis, Anti-bacterial Capabilities and Scanning Electron Microscopy of Novel Corticosteroid Thiopyran

2020 ◽  
Vol 17 ◽  
Author(s):  
Sultanat ◽  
Anam Ansari ◽  
Mohd Qamar ◽  
Shafiullah ◽  
Sartaj Tabassum ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Disulphide ◽  
Building Blocks ◽  
Biologically Active ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
Polycyclic Compounds ◽  
Wide Range ◽  
Scanning Electron

Background: Corticosteroids are important group of polycyclic compounds having a wide range of pharmacological and physiological properties. Thiopyran derivatives are important building blocks of many biologically active compounds. Objective: Keeping in mind the wide range of application of corticosteroid and thiopyran, herein we intend to develop a simple and efficient strategy to synthesize steroidal thiopyran derivatives starting with different commercially available corticosteroid and study their biological property. Materials and Methods: To achieve our aim, we employed a one-pot multicomponent synthesis of steroidal thiopyran derivatives by the reaction of corticosteriods, malononitrile and carbon disulphide in presence of triethyl amine as a catalyst. Results and Discussion : An array of novel thiopyran compounds were obtained with the highest product yield using Et3N. Scanning electron microscopy analysis manifested agglomeration pertaining to brick - shaped crystals of corticosteroid thiopyran. Synthesized compound were also found to be active as antibacterial agents. Conclusion: We describe a facile one-pot multicomponent synthesis of corticosteroid thiopyran derivatives which are found to possess antibacterial activity. Excellent yields of the products, simple work-up, easily available starting materials and non-chromatographic purification are some main advantages of this protocol.

The Discovery of Ultrasound Irradiation as a Useful Tool for Accelerating Petasis Three-component Reaction: Synthesis of α-Arylglycines

2018 ◽  
Vol 15 (2) ◽  
pp. 256-266 ◽  
Author(s):  
Fan Yun ◽  
Chunhui Cheng ◽  
Jingxuan Li ◽  
Pingwah Tang ◽  
Qipeng Yuan
Keyword(s):  
Reaction Time ◽  
Glyoxylic Acid ◽  
Reaction Times ◽  
Ultrasound Irradiation ◽  
Secondary Amines ◽  
One Pot ◽  
Petasis Reaction ◽  
Three Component Reaction ◽  
Wide Range ◽  
High Yields

Aim and Objective: α-Arylglycines belong to an important class of non-proteinogenic amino acids. Petasis 3-component, one-pot reaction lends itself to be suitable for the synthesis of α-Arylglycines. Because of the low reactivity, Petasis reaction requires long reaction time. Our objective is to use ultrasound irradiation to accelerate this versatile Petasis' synthesis of α-Arylglycines. Materials and Methods: Ultrasound irradiation as a physical tool to accelerate the Petasis 3-component reaction without any auxiliary catalyst can significantly shorten the reaction time. The operation is simple. It can be applied to a wide range of substrates. In order to highlight the remarkable utility of the ultrasound in Petasis reaction, we have compared side-by-side the reactivity between the reaction with ultrasound and the one without ultrasound. Results: Using ultrasound, the reaction times of Petasis reactions with various amine substrates including primary and secondary amines, heterocyclic amines, with a wide variety of boronic acids having different substituents (activating and deactivating groups) in the phenyl rings, and with glyoxylic acid and salicylic aldehyde were shortened from 5 to more than 20-fold. Conclusion: We have discovered the first examples of an efficient ultrasound-promoted approach for Petasis reaction to prepare a series of α-arylglycines in high yields and in excellent purities. The low reactivity of the reactions in this study were significantly enhanced by the ultrasound irradiation. By virtue of the acceleration and the operational simplicity, the present ultrasound assisted Petasis reaction can find applications in the synthetic areas of the already widely used Petasis three-component reaction.

Recent Progress on Synthesis and Bio-activities of Tetrahydropyrimidine-2-one derivatives

2021 ◽  
pp. 221-228
Author(s):  
Mayur S. Bhosale ◽  
K. Sarvanan ◽  
N. S. Dighe
Keyword(s):  
Biginelli Reaction ◽  
Building Blocks ◽  
Liquid Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
National Library ◽  
Pharmacological Activities ◽  
One Pot ◽  
Nmr Spectrometry ◽  
Derivatives Of

This review covers up synthesis, characterization and Pharmacological activities of various derivatives of 1,2,3,4-Tetrahydropyrimidine-2-one, including recent mechanistic advances, new building blocks and new pharmacological disclosures. Tetrahydropyrimidines (THPs) are one of the most important systems among the heterocycles. These compounds reported to have less toxicity to human and animals. Various synthesis strategies have been reported for different derivatives of Tetrahydropyrimidines, mainly these involves Biginelli reaction (condensation) consisting of one pot synthesis of 1,2,3,4-Tetrahydropyrimidine derivatives using urea, β-keto ester and aldehyde. These derivatives also forms important part as intermediate in the manufacture of various Pharmaceuticals. Techniques such as infrared spectroscopy, liquid chromatography-mass spectrometry, 1H NMR and 13C NMR spectrometry along with single crystal X-ray diffraction has been reported for structural characterization of these derivatives. U.S. National Library of Medicines, NIH and European PMC have reported many these derivatives. Some of derivatives have reported to have promising anti-bacterial, cytotoxic, antifungal, anti-inflammatory activities. Recently Ultrasound and Microwave promoted synthesis has shown promising results in synthesis of these derivatives. Many exciting prospects await for its exploitation in this fields.

scholarly journals Expedient synthesis of E-hydrazone esters and 1H-indazole scaffolds through heterogeneous single-atom platinum catalysis

2019 ◽  
Vol 5 (12) ◽  
pp. eaay1537 ◽  
Author(s):  
Cuibo Liu ◽  
Zhongxin Chen ◽  
Huan Yan ◽  
Shibo Xi ◽  
Kah Meng Yam ◽  
...  
Keyword(s):  
Density Functional ◽  
Stereoselective Synthesis ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Hydrogenation Reaction ◽  
Biologically Active ◽  
Single Atom ◽  
One Pot ◽  
Platinum Catalysis ◽  
Scalable Synthesis

Unprotected E-hydrazone esters are prized building blocks for the preparation of 1H-indazoles and countless other N-containing biologically active molecules. Despite previous advances, efficient and stereoselective synthesis of these compounds remains nontrivial. Here, we show that Pt single atoms anchored on defect-rich CeO2 nanorods (Pt1/CeO2), in conjunction with the alcoholysis of ammonia borane, promotes exceptionally E-selective hydrogenation of α-diazoesters to afford a wide assortment of N-H hydrazone esters with an overall turnover frequency of up to 566 hours−1 upon reaction completion. The α-diazoester substrates could be generated in situ from readily available carboxylic esters in one-pot hydrogenation reaction. Utility is demonstrated through concise, scalable synthesis of 1H-indazole–derived pharmaceuticals and their 15N-labeled analogs. The present protocol highlights a key mechanistic nuance wherein simultaneous coordination of a Pt site with the diazo N═N and ester carbonyl motifs plays a central role in controlling stereoselectivity, which is supported by density functional theory calculations.

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