Invited Review. A Combinatorial Approach to the Development of Environmentally Benign Organic Chemical Preparations

1999 ◽  
Vol 52 (2) ◽  
pp. 83 ◽  
Author(s):  
Christopher R. Strauss
Keyword(s):  
Hydrogen Transfer ◽  
Aldol Condensation ◽  
Aqueous Media ◽  
Environmentally Benign ◽  
Organic Chemical ◽  
Coupling Reactions ◽  
Heck Coupling ◽  
Solvent Free Conditions ◽  
Microwave Reactors ◽  
One Step

Enabling technologies and methodologies were established and combined to afford various environmentally benign processes for laboratory-scale organic synthesis and for the production of fine chemicals, intermediates and pharmaceuticals. The technologies comprised continuous and batch microwave reactors and catalytic membranes. The methodologies included solvent-free conditions, catalysed or uncatalysed processes, the use of aqueous media at high temperature and non-extractive techniques for product isolation. Applications included Hofmann eliminations, Willgerodt and Jacobs–Gould reactions, indole transformations, aldol condensation, Rupe and Meyer–Schuster rearrangements and C–C coupling reactions (including a tandem Heck coupling–dehydrogenation). New processes for catalytic etherification, uncatalysed hydrogen transfer and a one-step arylamidation were also developed. Typical products were N-(4-hydroxyphenyl)acetamide, carvacrol, a-phenylacetamide, cinnamaldehyde, cinnamyl alcohol, acetophenone, indole, 3-hydroxy-1,2-dimethyl-4-pyridone, di(2-phenylethyl) ether, di(cyclopropylmethyl) ether, 3-methylcyclopent-2-enone and a synthetic precursor of nalidixic acid.

Greener routes to organics and nanomaterials: Sustainable applications of nanocatalysts

2013 ◽  
Vol 85 (8) ◽  
pp. 1703-1710 ◽  
Author(s):  
Rajender S. Varma
Keyword(s):  
Heterocyclic Compounds ◽  
Large Scale ◽  
Aqueous Media ◽  
Reaction Medium ◽  
Waste Minimization ◽  
Synthetic Activity ◽  
Coupling Reactions ◽  
Structured Catalysts ◽  
Strategic Approach ◽  
Solvent Free Conditions

Sustainable synthetic activity involving alternate energy input and greener reaction medium under aqueous or solvent-free conditions is summarized. This includes the synthesis of heterocyclic compounds, coupling reactions, and a variety of reactions catalyzed by basic water or recyclable and reusable magnetic nanocatalysts in aqueous media using microwave (MW) irradiation. Micropine-structured catalysts and magnetic nanoferrites and their post-synthetic modification with ligands and other nanometals serve as sustainable nanocatalysts in benign media. The strategic approach attempts to fulfill most of the green chemistry principles in a comprehensive manner and aims to create sustainable functional chemicals that may find large-scale use with significant waste minimization.

Polydopamine: An Emerging Material in the Catalysis of Organic Transformations

Synthesis ◽  
2018 ◽  
Vol 51 (14) ◽  
pp. 2829-2838 ◽  
Author(s):  
Attila Kunfi ◽  
Gábor London
Keyword(s):  
Carbonyl Compounds ◽  
Materials Science ◽  
Type Systems ◽  
Short Review ◽  
Environmentally Benign ◽  
Coupling Reactions ◽  
Heck Coupling ◽  
Organic Transformations ◽  
Acid Base ◽  
Metal Catalysis

Polydopamine, a ‘mussel-inspired’ polymer, has been explored extensively in materials science as a universal coating. However, as an easily available, stable and environmentally benign material, it has recently been discovered to demonstrate catalytic applications. In this short review, we briefly discuss the main approaches employing polydopamine in the catalysis of organic transformations. These include metal/polydopamine-type systems and metal-free approaches that exploit the acid/base properties of this versatile polymer.1 Introduction2 PDA and Metal Catalysis2.1 Reduction of Nitroaryl Compounds to Anilines2.2 Reduction of Carbonyl Compounds to Alcohols2.3 Suzuki and Heck Coupling Reactions2.4 Other Reactions Catalyzed by M/PDA-Type Systems3 PDA as a Catalyst Itself4 Conclusion

scholarly journals A New Nanomagnetic Pd-Co Bimetallic Alloy as Catalyst in the Mizoroki-Heck and Buchwald–Hartwig Amination Reactions in Aqueous Media

2021 ◽  
Author(s):  
Sara Sobhani ◽  
Hamed Zarei ◽  
José Miguel Sansano
Keyword(s):  
Catalytic Activity ◽  
Reduction Method ◽  
Bimetallic Catalyst ◽  
Aqueous Media ◽  
Catalytic Performance ◽  
Cooperative Effect ◽  
Coupling Reactions ◽  
Heck Coupling ◽  
Bimetallic Alloy ◽  
Amination Reaction

Abstract A Pd-Co bimetallic alloy encapsulated in melamine-based dendrimer supported on magnetic nanoparticles denoted as γ-Fe2O3@MBD/Pd-Co was synthesized by a facile co-complexation-reduction method and characterized sufficiently. The catalytic evaluation of γ-Fe2O3@MBD/Pd-Co showed promising results in the Mizoroki-Heck and Buchwald-Hartwig amination reactions of various iodo-, bromo- and challenging chloroarenes in aqueous media. The synergetic cooperative effect of both Pd and Co and dispersion of the catalyst in water due to the encapsulation of γ-Fe2O3 by melamine-based dendrimer lead to high catalytic performance compared with the monometallic counterparts. The dispersion of the magnetic catalyst also facilitates the recovery and reuse of the catalyst by ten consecutive extraction and final magnetic isolation with no loss of catalytic activity, keeping its structure unaltered. Remarkably, this is the first paper on the use of palladium-cobalt bimetallic catalyst for Buchwald-Hartwig amination reaction and the first magnetically recyclable Pd/Co bimetallic catalyst in the Mizoroki-Heck coupling reactions.

scholarly journals An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

2017 ◽  
Vol 13 ◽  
pp. 1717-1727 ◽  
Author(s):  
Carolina S García ◽  
Paula M Uberman ◽  
Sandra E Martín
Keyword(s):  
Microwave Irradiation ◽  
Aqueous Media ◽  
Coupling Reaction ◽  
Catalyst Loading ◽  
Coupling Reactions ◽  
Heck Coupling ◽  
Turnover Frequency ◽  
High Turnover ◽  
Aryl Bromides ◽  
Simple Product

Aqueous Mizoroki–Heck coupling reactions under microwave irradiation (MW) were carried out with a colloidal Pd nanocatalyst stabilized with poly(N-vinylpyrrolidone) (PVP). Many stilbenes and novel heterostilbenes were achieved in good to excellent yields starting from aryl bromides and different olefins. The reaction was carried out in a short reaction time and with low catalyst loading, leading to high turnover frequency (TOFs of the order of 100 h−1). The advantages like operational simplicity, high robustness, efficiency and turnover frequency, the utilization of aqueous media and simple product work-up make this protocol a great option for stilbene syntheses by Mizoroki–Heck reaction.

scholarly journals Ionic Liquids and Ohmic Heating in Combination for Pd-Catalyzed Cross-Coupling Reactions: Sustainable Synthesis of Flavonoids

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1564
Author(s):  
Vera L. M. Silva ◽  
Raquel G. Soengas ◽  
Artur M. S. Silva
Keyword(s):  
Ionic Liquid ◽  
Ohmic Heating ◽  
Aqueous Media ◽  
Cross Coupling ◽  
Chemical Processes ◽  
Environmentally Benign ◽  
Coupling Reactions ◽  
Supported Ionic Liquid ◽  
Cross Coupling Reactions ◽  
Increasing Demand

In order to meet the increasing demand for environmentally benign chemical processes, we developed a Suzuki–Miyaura reaction protocol based on the combination of ohmic heating (ΩH) and supported ionic liquid phase catalysis (SILPC) in aqueous media. This methodology was applied to the synthesis of a series of flavonoid derivatives, including isoflavones, styrylisoflavones, and diarylalkenylisoflavones.

Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian
Keyword(s):  
Functional Group ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivatives ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
One Step ◽  
Aryl Tosylates ◽  
Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

Withdrawal Notice: Recent Advances in Sonogashira Cross-Coupling Reactions Under Solvent-Free Conditions

2020 ◽  
Vol 24 ◽  
Author(s):  
Teng Wang ◽  
Zongrui Liu ◽  
Songlin Wang ◽  
Esmail Vessally
Keyword(s):  
Organic Chemistry ◽  
Editorial Policy ◽  
Cross Coupling ◽  
Solvent Free ◽  
Coupling Reactions ◽  
Editorial Policies ◽  
Cross Coupling Reactions ◽  
Recent Advances ◽  
Solvent Free Conditions ◽  
Copyright Permission

The article has been withdrawn at the request of editor of the journal Current Organic Chemistry: Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused. The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/editorial-policies-main.php BENTHAM SCIENCE DISCLAIMER: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript, the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.

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