Biocatalytic synthesis of novel electronic and photovoltaic materials

2005 ◽  
Vol 77 (1) ◽  
pp. 263-272 ◽  
Author(s):  
Ravi Mosurkal ◽  
Rajesh Kumar ◽  
Ferdinando F. Bruno ◽  
Ramaswamy Nagarajan ◽  
Lynne Samuelson ◽  
...  

A new class of ruthenium complex-based macrodye and a dinuclear complex were synthesized via a biocatalytic route employing hematin as an efficient biocatalyst. The photovoltaic overall efficiency of the dinuclear complex was found to be 2.1 % and higher than the polymeric complex (0.33 %). Furthermore, we have developed an environmentally benign methodology for the synthesis of novel pegylated polyphenolics. The reaction conditions used do not require any organic solvents, and all the reactions were performed in aqueous media. The synthesized polymers were soluble in both organic and aqueous media, and provide further opportunity to tailor the properties. Finally, a novel biomimetic method for the synthesis of a conducting molecular complex of polypyrrole and of thiophene substitute in the presence of a polyelectrolyte, such as polystyrene sulfonate (SPS), is presented. A synthetic enzyme based on hematin was used to catalyze the polymerization of pyrrole (PYR) and 3,4-ethylenedioxythiophene (EDOT) in the presence of SPS. Copolymers of EDOT and PYR have also been synthesized, and these novel materials have been shown to exhibit high electrical conductivity.

2012 ◽  
Vol 77 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Khalil Tabatabaeian ◽  
Hannaneh Heidari ◽  
Alireza Khorshidi ◽  
Manouchehr Mamaghani ◽  
Nosrat Mahmoodi

The one-pot domino Knoevenagel-type condensation/Michael reaction of aromatic, heteroaromatic and aliphatic aldehydes with 4-hydroxycoumarin in aqueous media in the presence of ruthenium salt as homogeneous catalyst was investigated. It was found that 5 mol% of RuCl3.nH2O catalyzes biscoumarin synthesis in high yields (70-95%) under optimised, mild, green and environmentally benign reaction conditions in short times (25-35min).


SynOpen ◽  
2021 ◽  
Author(s):  
Hassan Farhid ◽  
Mohammad Mahdi Rostami ◽  
Ahmad Shaabani ◽  
Behrouz Notash

An efficient and straightforward approach has been established for the preparation of new class of depsipeptide structures via isocyanide-based consecutive Bargellini/Passerini multicomponent reactions. 3-Carboxamido-isobutyric acids bearing an amide bond were supplied via Bargellini multicomponent reaction from isocyanides, acetone, and chloroform in the presence of sodium hydroxide. Next, via the Passerini multicomponent reaction strategy, a new class of depsipeptides was synthesized using the Bargellini reaction products, isocyanides, and aldehydes under environmentally benign reaction conditions. The prepared depsipeptides have more flexible structures than their pseudopeptidic analogs. Using cheap and readily available starting materials, mild reaction conditions, simple procedures, and high yields are the advantages of the present strategy.


2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Hamzeh Kiyani ◽  
Fatemeh Ghorbani

Abstract2-Amino-4-aryl-4H-benzo[h]chromenes and 3-amino-1-aryl-1H-benzo[f]chromenes were prepared by treating cyano-methylene compounds (malononitrile or ethyl cyanoacetate), substituted aromatic aldehydes, and naphtholic compounds in the presence of potassium phthalimide as a green, mild, efficient, and commercially available organocatalyst in aqueous media. The procedure was readily conducted and affords remarkable advantages such as safety, short reaction times, environmentally benign milder reaction conditions, no organic solvent required, and high yields.


Author(s):  
Wolfgang Zimmermann

The global production of plastics made from non-renewable fossil feedstocks has grown more than 20-fold since 1964. While more than eight billion tons of plastics have been produced until today, only a small fraction is currently collected for recycling and large amounts of plastic waste are ending up in landfills and in the oceans. Pollution caused by accumulating plastic waste in the environment has become worldwide a serious problem. Synthetic polyesters such as polyethylene terephthalate (PET) have widespread use in food packaging materials, beverage bottles, coatings and fibres. Recently, it has been shown that post-consumer PET can be hydrolysed by microbial enzymes at mild reaction conditions in aqueous media. In a circular plastics economy, the resulting monomers can be recovered and re-used to manufacture PET products or other chemicals without depleting fossil feedstocks and damaging the environment. The enzymatic degradation of post-consumer plastics thereby represents an innovative, environmentally benign and sustainable alternative to conventional recycling processes. By the construction of powerful biocatalysts employing protein engineering techniques, a biocatalytic recycling of PET can be further developed towards industrial applications. This article is part of a discussion meeting issue ‘Science to enable the circular economy’.


2019 ◽  
Vol 10 (3) ◽  
pp. 276-279
Author(s):  
V. Dukhnitsky ◽  
I. Derkach ◽  
M. Plutenko ◽  
I. Fritsky ◽  
S. Derkach

A new class of highly valent iron compounds is formed by atmospheric oxidation in aqueous media and it is extremely stable both in solid and soluble conditions and may exist indefinitely in a medium without signs of degradation. The first clathrochelate complexes of iron (IV) are infinitely stable in water and readily available from simple, commercially available, inexpensive source materials with surprisingly mild reaction conditions. To create new drugs on their bases, research on their toxicity is required. In this study, the results of preclinical studies of a new iron clathrochelates drug are presented. Experiments were carried out on white rats and quails, which in the previous experiment were divided into five experimental and two control groups. The solution of iron clathrochelate complexes was administered intragastrically in doses 50, 500, 1000, 2000 and 5000 mg/kg, respectively. Our results have shown that there were no grounds for using rats in the advanced experiment because the conducted research has established that iron clathrochelate is non toxic to rats. Thus, the minimum dose of iron clathrochelate complexes did not cause death of quails, and the largest dose caused 100% mortality. The basic experiment was conducted on 6 groups of birds, each consisting of 7 quails. The drug was administered in the following doses: 500, 600, 700, 800, 900, 1000 mg/kg. The monitoring observation of the laboratory birds lasted for 14 days. It has been established that the average lethal dose of clathrochelate of the investigated drug for internal administration in quails is 764 ± 33 mg/kg. According to the classification of chemicals by the degree of danger (State ST 12.1.007-76), iron (IV) clathrochelate complexes correspond to the third class of hazard, and according to the classification of substances for toxicity they are classified as category 4 (low toxicity substances). The prospect of further research is to investigate the pharmacological and toxicological properties of iron (IV) clathrochelate for chronic toxicity.


2019 ◽  
Vol 23 (16) ◽  
pp. 1778-1788 ◽  
Author(s):  
Gurpreet Kaur ◽  
Arvind Singh ◽  
Kiran Bala ◽  
Mamta Devi ◽  
Anjana Kumari ◽  
...  

A simple, straightforward and efficient method has been developed for the synthesis of (E)-3-(arylimino)indolin-2-one derivatives and (E)-2-((4-methoxyphenyl)imino)- acenaphthylen-1(2H)-one. The synthesis of these biologically-significant scaffolds was achieved from the reactions of various substituted anilines and isatins or acenaphthaquinone, respectively, using commercially available, environmentally benign and naturally occurring organic acids such as mandelic acid or itaconic acid as catalyst in aqueous medium at room temperature. Mild reaction conditions, energy efficiency, good to excellent yields, environmentally benign conditions, easy isolation of products, no need of column chromatographic separation and the reusability of reaction media are some of the significant features of the present protocol.


Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 720
Author(s):  
Satomi Niwayama

Symmetric organic compounds are generally obtained inexpensively, and therefore they can be attractive building blocks for the total synthesis of various pharmaceuticals and natural products. The drawback is that discriminating the identical functional groups in the symmetric compounds is difficult. Water is the most environmentally benign and inexpensive solvent. However, successful organic reactions in water are rather limited due to the hydrophobicity of organic compounds in general. Therefore, desymmetrization reactions in aqueous media are expected to offer versatile strategies for the synthesis of a variety of significant organic compounds. This review focuses on the recent progress of desymmetrization reactions of symmetric organic compounds in aqueous media without utilizing enzymes.


2005 ◽  
Vol 494 ◽  
pp. 363-368 ◽  
Author(s):  
D. Lončarević ◽  
Ž. Čupić

Poly(4-vinylpyridine-co-divinylbenzene)-Co2+ was characterized using infrared spectroscopy (IR), thermogravimetric analysis (TG-DTA), N2-physisorption and polarography. Thermal analysis suggests sufficient thermal stability of the polymer support, under reaction conditions. From polarography measurements, the Co2+ content on polymer-supported catalysts is estimated and it was proved that no significant leaching occurred during the activity tests. At the molecular level, FTIR of P4VP-DVB-Co2+ reveals that the pyridine nitrogen lone pair coordinates to the metal center in the polymeric complex. The obtained P4VP-DVB-Co2+ catalysts performed interesting catalytic activity in reaction of the cyclohexane oxidation with air, indicating that increasing Co2+ content lowers the initiation temperature and raises the decomposition of cyclohexylhydroperoxide.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 3031 ◽  
Author(s):  
Xiaodong Tang ◽  
Songlei Zhu ◽  
Ying Ma ◽  
Ren Wen ◽  
Lanqi Cen ◽  
...  

A green, convenient and tandem procedure for the efficient synthesis of highly substituted indeno[1,2-b]pyrrole and acenaphtho[1,2-b]pyrrole derivatives by domino three-component reaction of tryptamine/benzylamine, 1,3-dicarbonyl compounds and ninhydrin/ acenaphthenequinone is described. The significant features of this procedure were characterized by mild reaction conditions, high yields, operational simplicity and it being environmentally benign.


Author(s):  
Andreas A Grauer ◽  
Burkhard König

Cα-Tetrasubstituted α-amino acids are important building blocks for the synthesis of peptidemimetics with stabilized secondary structure, because of their ability to rigidify the peptide backbone. Recently our group reported a new class of cyclic Cα-tetrasubstituted tetrahydrofuran α-amino acids prepared from methionine and aromatic aldehydes. We now report the extension of this methodology to aliphatic aldehydes. Although such aldehydes are prone to give aldol products under the reaction conditions used, we were able to obtain the target cyclic amino acids in low to moderate yields and in some cases with good diastereoselectivity.


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