Bronsted acidic surfactants: efficient organocatalysts for diverse organic transformations

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Abhijeet Singh ◽  
Pargat Singh ◽  
Mahendra Nath
Keyword(s):  
Micelle Formation ◽  
Cost Effective ◽  
Reaction Rates ◽  
Environmentally Benign ◽  
Organic Transformations ◽  
Catalytic Systems ◽  
Bond Forming ◽  
The Past ◽  
Waste Production ◽  
Combined Catalysts

Abstract Organic transformations using efficient, atom-economical, cost-effective and environmentally benign strategies for the construction of diversified molecules have attracted synthetic chemists worldwide in recent years. These processes often minimize the waste production and avoid the use of hazardous flammable organic solvents. Among various green protocols, the procedures using surfactant-based catalytic systems have received a considerable attention in organic synthesis. In this context, Bronsted acidic surfactants have emerged as efficient catalysts for various C–C, C–O, C–N and C–S bond forming reactions. Many of these reactions occur in water, as Bronsted acidic surfactants have a unique ability of creating hydrophobic pocket through micelle formation in aqueous medium and the substrate molecules react efficiently to afford the targeted products in good yields. In the past, Bronsted acidic surfactant combined catalysts successfully displayed their potential to accelerate the reaction rates of diverse organic transformations. This chapter presents a complete overview on Bronsted acidic surfactants catalyzed organic reactions to construct a variety of aromatic and heteroaromatic molecular frameworks.

Formation of Carbon-Nitrogen Bond Mediated by Hypervalent Iodine Re-agents Under Metal-free Conditions

2020 ◽  
Vol 24 ◽  
Author(s):  
Yaxin O Yang ◽  
Xi Wang ◽  
Jiaxi Xiao ◽  
Yadong Li ◽  
Fengxia Sun ◽  
...  
Keyword(s):  
Building Blocks ◽  
Review Article ◽  
Hypervalent Iodine ◽  
Coupling Reactions ◽  
Organic Transformations ◽  
Metal Free ◽  
Bond Forming ◽  
The Past ◽  
Oxidative Coupling Reactions ◽  
Nitrogen Bond

: In the past several decades, hypervalent iodine chemistry has witnessed prosperous development as hypervalent iodine reagents have been widely used in various organic transformations. Specifically, hypervalent iodine reagents have been vastly used in various bond-forming reactions. Among these oxidative coupling reactions, the reactions involving the formation of C-N bond have been extensively explored to construct various heterocyclic skeletons and synthesize various useful building blocks. This review article is to summarize all the transformations in which carbon-nitrogen bond formation occurred by using hypervalent iodine reagents under metal-free conditions.

Ultrasound-Promoted Organic Synthesis – A Recent Update

2021 ◽  
Vol 25 ◽  
Author(s):  
Goutam Brahmachari ◽  
Nayana Nayek ◽  
Mullicka Mandal ◽  
Anindita Bhowmick ◽  
Indrajit Karmakar
Keyword(s):  
Organic Chemistry ◽  
Green Chemistry ◽  
Organic Synthesis ◽  
Ultrasound Irradiation ◽  
Present Review ◽  
Organic Transformations ◽  
Reaction Conditions ◽  
Catalytic Systems ◽  
Bond Forming ◽  
Reducing Energy

: Ultrasonication, nowadays, is well-regarded as an effective green tool in implementing a plethora of organic transformations. The last decade has seen quite useful applications of ultrasound irradiation in synthetic organic chemistry. Ultrasound has already come out as a unique technique in green chemistry practice, for its inherent properties of minimizing wastes and reducing energy and time, thereby increasing the product yields with higher purities under milder reaction conditions. The present review summarizes ultrasound-promoted useful organic transformations involving both carbon-carbon and carbon-heteroatom (N, O, S) bond-forming reactions in the absence or presence of varying catalytic systems, reported during the period 2016-2020.

Ionic Liquid Assisted C-C Bond Formation

2020 ◽  
Vol 24 (16) ◽  
pp. 1853-1875
Author(s):  
Mandeep Kaur ◽  
Opinder Kaur ◽  
Rahul Badru ◽  
Sandeep Kaushal ◽  
Pritpal Singh
Keyword(s):  
Ionic Liquids ◽  
Heterogeneous Catalysts ◽  
Bond Formation ◽  
Solvent System ◽  
Solid Support ◽  
Organic Transformations ◽  
Diverse Range ◽  
Bond Forming ◽  
The Past ◽  
Wide Range

With their ability to dissolve inorganic as well as organic materials, ionic liquids have emerged as a versatile solvent system for a diverse range of organic transformations. In the past few decades, the literature has witnessed remarkable advances in a wide range of organic conversions carried out in the presence of various imidazolium, pyridinium, pyrrolidinium, quinolinium and diazobicyclo-octane based ionic liquids. In the reaction, ionic liquids serve as a solvent, catalyst or sometimes both. In certain cases, they are also modified with metal nanoparticles or complexes to form heterogeneous catalysts or are immobilized onto solid support like agar-agar to act as solid-support catalysts. Reactions catalysed by ionic liquids incorporating chiral catalysts possess the advantageous features of being highly enantioselective and reproducible, besides being economical and easy to handle. In this review, an updated insight regarding the role played by ionic liquids in various C-C bond-forming organic reactions, has been summarized.

Lewis Acid Surfactant Combined (LASC) Catalyst as a Versatile Heterogeneous Catalyst in Various Organic Transformations

2020 ◽  
Vol 17 (2) ◽  
pp. 124-140
Author(s):  
Ruby Singh ◽  
Diksha Bhardwaj ◽  
Shakeel Ahmad Ganaie ◽  
Aakash Singh
Keyword(s):  
Lewis Acids ◽  
Ring Opening ◽  
Heterogeneous Catalysts ◽  
Cost Effective ◽  
High Water ◽  
Colloidal Dispersions ◽  
Present Review ◽  
Organic Transformations ◽  
Bond Forming ◽  
Carbon Carbon Bond

Surfactant Aided Lewis Acids (LASCs) make an appearance as one of the efficient and substantial heterogeneous catalysts. Recently, various LASCs have been used as green and heterogeneous catalysts in organic synthesis due to their high water stability, recyclability, cost-effective nature and their ability to create stable colloidal dispersions. In the present review, we have discussed a variety of carbon-carbon bond forming, ring opening, addition and multi-component reactions for the synthesis of various biologically important heterocyclic compounds that have been successfully catalyzed by LASCs. In most cases, the catalytic activity of LASCs was found to be better in water in comparison to other organic solvents, which attracts special attention towards the present review.

Microwave-accelerated Approaches to Diverse Xanthenes: A Review

2020 ◽  
Vol 7 (2) ◽  
pp. 99-111
Author(s):  
Jagmeet Singh ◽  
Ankit Lathwal ◽  
Shalini Agarwal ◽  
Mahendra Nath
Keyword(s):  
Reaction Rates ◽  
Waste Generation ◽  
Reaction Conditions ◽  
Catalytic Systems ◽  
Heterocyclic Molecules ◽  
The Past ◽  
Wide Range ◽  
Pharmaceutical Properties ◽  
Synthetic Methodologies ◽  
High Yields

Microwave-accelerated methods have emerged as powerful tools in organic synthesis to enhance the reaction rates and provide products with high yields, improved selectivity, lower energy consumption, mild reaction conditions and negligible waste generation. Xanthenes are an important class of biologically important oxygen-containing heterocyclic molecules that possess a multitude of pharmaceutical properties. By considering the medicinal and material significance of these molecules, a large number of synthetic methodologies and catalytic systems have been reported for the synthesis of a wide range of xanthenes in the past. However, the focus of the present review is to summarize various microwave-assisted protocols for the synthesis of diversely substituted xanthene analogues.

Regulatory and sustainability initiatives lead to improved polyaminopolyamide epichlorohydrin (PAE) wet-strength resins and paper products

TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 519-532 ◽  
Author(s):  
Mark Crisp ◽  
Richard Riehle
Keyword(s):  
Health And Safety ◽  
Cost Effective ◽  
Worker Safety ◽  
Regulatory Requirements ◽  
Wet Strength ◽  
The Past ◽  
Consumer Safety ◽  
Federal Institute ◽  
Sustainability Initiatives ◽  
The Impact

Polyaminopolyamide-epichlorohydrin (PAE) resins are the predominant commercial products used to manufacture wet-strengthened paper products for grades requiring wet-strength permanence. Since their development in the late 1950s, the first generation (G1) resins have proven to be one of the most cost-effective technologies available to provide wet strength to paper. Throughout the past three decades, regulatory directives and sustainability initiatives from various organizations have driven the development of cleaner and safer PAE resins and paper products. Early efforts in this area focused on improving worker safety and reducing the impact of PAE resins on the environment. These efforts led to the development of resins containing significantly reduced levels of 1,3-dichloro-2-propanol (1,3-DCP) and 3-monochloropropane-1,2-diol (3-MCPD), potentially carcinogenic byproducts formed during the manufacturing process of PAE resins. As the levels of these byproducts decreased, the environmental, health, and safety (EH&S) profile of PAE resins and paper products improved. Recent initiatives from major retailers are focusing on product ingredient transparency and quality, thus encouraging the development of safer product formulations while maintaining performance. PAE resin research over the past 20 years has been directed toward regulatory requirements to improve consumer safety and minimize exposure to potentially carcinogenic materials found in various paper products. One of the best known regulatory requirements is the recommendations of the German Federal Institute for Risk Assessment (BfR), which defines the levels of 1,3-DCP and 3-MCPD that can be extracted by water from various food contact grades of paper. These criteria led to the development of third generation (G3) products that contain very low levels of 1,3-DCP (typically <10 parts per million in the as-received/delivered resin). This paper outlines the PAE resin chemical contributors to adsorbable organic halogens and 3-MCPD in paper and provides recommendations for the use of each PAE resin product generation (G1, G1.5, G2, G2.5, and G3).

Metal and Non-Metal Catalysts in the Synthesis of Five-Membered S-Heterocycles

2019 ◽  
Vol 16 (2) ◽  
pp. 258-275 ◽  
Author(s):  
Navjeet Kaur
Keyword(s):  
Organic Synthesis ◽  
Biological Activities ◽  
Reaction Times ◽  
Research Field ◽  
Environmentally Benign ◽  
Metal Catalyst ◽  
Efficient Synthesis ◽  
Heterocyclic Molecules ◽  
The Past ◽  
Harsh Conditions

Background:A wide variety of biological activities are exhibited by N, O and S containing heterocycles and recently, many reports appeared for the synthesis of these heterocycles. The synthesis of heterocycles with the help of metal and non-metal catalyst has become a highly rewarding and important method in organic synthesis. This review article concentrated on the synthesis of S-heterocylces in the presence of metal and non-metal catalyst. The synthesis of five-membered S-heterocycles is described here.Objective:There is a need for the development of rapid, efficient and versatile strategy for the synthesis of heterocyclic rings. Metal, non-metal and organocatalysis involving methods have gained prominence because traditional conditions have disadvantages such as long reaction times, harsh conditions and limited substrate scope.Conclusion:The metal-, non-metal-, and organocatalyst assisted organic synthesis is a highly dynamic research field. For ßthe chemoselective and efficient synthesis of heterocyclic molecules, this protocol has emerged as a powerful route. Various methodologies in the past few years have been pointed out to pursue more sustainable, efficient and environmentally benign procedures and products. Among these processes, the development of new protocols (catalysis), which avoided the use of toxic reagents, are the focus of intense research.

Organocatalyzed Heterocyclic Transformations In Green Media: A Review

2020 ◽  
Vol 07 ◽  
Author(s):  
Neslihan Demirbas ◽  
Ahmet Demirbas
Keyword(s):  
Hydrogen Bonding ◽  
Phase Transfer ◽  
Noncovalent Interactions ◽  
Binding Capacity ◽  
Chemical Transformations ◽  
Organic Transformations ◽  
Phase Transfer Catalysts ◽  
Waste Production ◽  
Synthetic Methodologies ◽  
Organocatalytic Reactions

Background: Since the discovery of metal-free catalysts or organocatalysts about twenty years ago, a number of small molecules with different structures have been using to accelerate organic transformations. With the development of environmental awareness, in order to obtain highly privileged scaffolds, scientists have directed their studies towards the synthetic methodologies which minimize or preferably eliminate the formation of waste, avoid from toxic solvents and reagents and use renewable starting materials as far as possible. Methods: In this connection, the organocatalytic reactions providing efficiency and selectivity for most of case have become an endless topic in organic chemistry since several advantages from both practical and environmental standpoints. Organocatalysts supplying transformation of reactants into products with the least possible waste production have been serving to the concept of green chemistry. Results and Conclusion: Organocatalysts have been classified on the basis of their binding capacity to the substrate with covalently or noncovalent interactions involving hydrogen bonding and electrostatic interaction. Diverse types of small organic compounds including proline and its derivatives, phase-transfer catalysts, (thio)urease, phosphoric acids, sulfones, N-oxides, guanidines, cinchona derivatives, aminoindanol and amino acids have been utilized as hydrogen bonding organocatalysts in different chemical transformations.

scholarly journals Modern Synthetic Methods for the Stereoselective Construction of 1,3-Dienes

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 249
Author(s):  
Raquel G. Soengas ◽  
Humberto Rodríguez-Solla
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Functional Group ◽  
Biological Activities ◽  
Synthetic Methods ◽  
Bond Forming ◽  
Drug Candidates ◽  
The Past ◽  
Wide Range

The 1,3-butadiene motif is widely found in many natural products and drug candidates with relevant biological activities. Moreover, dienes are important targets for synthetic chemists, due to their ability to give access to a wide range of functional group transformations, including a broad range of C-C bond-forming processes. Therefore, the stereoselective preparation of dienes have attracted much attention over the past decades, and the search for new synthetic protocols continues unabated. The aim of this review is to give an overview of the diverse methodologies that have emerged in the last decade, with a focus on the synthetic processes that meet the requirements of efficiency and sustainability of modern organic chemistry.

A recent overview on the porphyrin-based π-extended small molecules as donors and acceptors for high-performance organic solar cells

2021 ◽  
Author(s):  
Venkatesh Piradi ◽  
Feng Yan ◽  
Xunjin Zhu ◽  
Wai-Yeung Raymond Wong
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Small Molecules ◽  
Organic Solar Cells ◽  
High Performance ◽  
Cost Effective ◽  
Effective Alternative ◽  
The Past ◽  
Cost Effective Alternative ◽  
Silicon Based

Organic solar cells (OSCs) have been considered as a promising cost-effective alternative to silicon-based solar cell counterparts due to their lightweight, mechanical flexibility, and easy fabrication features. Over the past...

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