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Conducting electrochemical organic synthesis in/on whole water media is undoubtedly a highly green approach, which avoids the usage of organic solvents, and sometimes organic supporting electrolytes. In this review, the electrochemical organic syntheses in/on whole water environment are reviewed, especially including the reactions conducted both in organic solvent and water for comparisons. This review discussed anodic and cathodic reaction, respectively, including the C−H oxidation, hydroxylation, dehydrogenative cross coupling, functionalization of alkenes, cathodic oxidation, hydrogenation, reductive cross coupling, and so on. As the reduction of CO2, conversion biomass, and waste water disposal are frequently performed in water, and have already been reviewed recently. These topics are not included in this review. [ABSTRACT FROM AUTHOR]

This study uses a rapid tandem mass‐spectrometry method to determine water content in complex organic solutions. Emphasis is placed on trace‐water analysis by a fast and accurate alternative to the Karl–Fischer method. In this new method, water is captured by a charge‐labeled molecular probe. Water binds strongly with high specificity to the strongly electrophilic aldehyde site in a charge‐labelled molecule (N‐methylpyridinium); competitive binding by other analytes is effectively discriminated against in the mass‐measurement step. Quantitative determinations are made over a wide concentration range, 0.001 % (10 ppm) to 99 %, with better than 10 % relative standard deviation, along with short (1 min) analysis times using small sample volumes (several μL). Applications include water measurement in simple organic solvents, for example, deuterated solvents, as well as in complex mixtures, for example, organic reaction mixtures. Additionally, this method allows for water monitoring in levitated droplets. Mechanistic investigations into the impact of water on important chemical processes in organic synthesis and environmental science are reported. [ABSTRACT FROM AUTHOR]

This study uses a rapid tandem mass‐spectrometry method to determine water content in complex organic solutions. Emphasis is placed on trace‐water analysis by a fast and accurate alternative to the Karl–Fischer method. In this new method, water is captured by a charge‐labeled molecular probe. Water binds strongly with high specificity to the strongly electrophilic aldehyde site in a charge‐labelled molecule (N‐methylpyridinium); competitive binding by other analytes is effectively discriminated against in the mass‐measurement step. Quantitative determinations are made over a wide concentration range, 0.001 % (10 ppm) to 99 %, with better than 10 % relative standard deviation, along with short (1 min) analysis times using small sample volumes (several μL). Applications include water measurement in simple organic solvents, for example, deuterated solvents, as well as in complex mixtures, for example, organic reaction mixtures. Additionally, this method allows for water monitoring in levitated droplets. Mechanistic investigations into the impact of water on important chemical processes in organic synthesis and environmental science are reported. [ABSTRACT FROM AUTHOR]

The use of volatile solvents for organic synthesis is nowadays questioned due to their negative impact on the environnement. To develop sustainable and environmentally friendly methodologies, we propose to combine two green chemistry concepts: the use of bioinspired solvents: natural deep eutectic solvents (NaDES), and mechanochemistry. Using the Suzuki‐Miyaura coupling as a model reaction, we described an efficient mechanochemical method with NaDES as a LAG (liquid‐assisted grinding) additive with short reaction times and without any ligand or additional heating. A mechanochemical extraction was also used to reduce the amounts of extraction solvents and the total time of the synthesis process. [ABSTRACT FROM AUTHOR]

Multicomponent reactions are crucial for operating organic synthesis. In today's world, chemists concentrate on greener methodologies that cater to rising environmental concerns. Most conventional organic solvents are harsh on the environment, which can be addressed by environmentally and pocket‐friendly Deep eutectic solvents (DES). Organic synthesis via MCR in the presence of DES has resulted in the blend of green methodology and green solvent for organic transformations. Forasmuch as addressing the environmental concerns and developing higher heterocycles, our review focuses on the literature published on the DES‐mediated Multicomponent synthesis of N‐Heterocyclic compounds. [ABSTRACT FROM AUTHOR]

Green chemistry is the basis for fast‐growing, eco‐friendly, alternative sustainable technologies for the development of chemical products without the use or generation of hazardous catalysts. The role of naturally occurring fruit juice as a catalyst or solvent in organic synthesis has gained focused interest across the globe. Lemon juice‐mediated synthesis has been widely explored recently as a highly significant, selective solvent and biocatalyst in organic synthesis. This review presents recent developments on lemon‐juice mediated transformations and their application to synthesize molecules or building blocks of pharmaceutical interest. We believe this review article will be of interest to researchers both in academic and industrial settings focused on developing novel pharmacophores from a green chemistry principles perspective. [ABSTRACT FROM AUTHOR]

Imines are important intermediates in drug synthesis. Photocatalytic aerobic oxidative coupling of amines has been considered as a clean and promising way to produce imines and has attracted great attention. Herein, we designed and synthesized a novel two‐dimensional porphyrin‐based covalent organic framework (Por‐BC‐COF) which adopts an AA stacking mode with excellent crystallinity, high Brunauer–Emmett–Teller surface areas (1200 m2 g−1), wide light absorption range (200–1300 nm) and good stability in a variety of organic solvents. Por‐BC‐COF can be used as a metal‐free heterogeneous photocatalyst for the photocatalytic oxidation of amines to imines under visible light and red light with a high yield (97 %). This work presents a novel and efficient COF photocatalyst in the application of light‐driven organic synthesis. [ABSTRACT FROM AUTHOR]

In the last twenty years, N‐heterocyclic carbenes (NHCs) have been extensively studied for their application as organocatalysts in stereoselective synthesis as well as ligands for transition metals‐promoted synthetic methodologies. Derived mainly from azolium salts, NHCs have demonstrated exceptional versatility in their generation usually performed by deprotonation or reduction (chemical or electrochemical). In particular, the generation of NHC under electrochemical conditions, starting from azolium‐based ionic liquids, has proven to be a successful green approach and demonstrated wide applicability in organic synthesis. In this Personal Account, the application of electrogenerated NHCs in organic synthesis will be discussed, with a particular attention to the different reactivity in ionic liquids compared to classical organic solvents. [ABSTRACT FROM AUTHOR]

Microemulsions are clear, stable, isotropic mixtures of oil, water, and surfactant, frequently in combination with a cosurfactant. These systems are currently of interest to the pharmaceutical scientist because of their considerable potential to act as drug delivery vehicles by incorporating a wide range of drug molecules. The purpose of this work is to solubilize in AOT [sodium bis(2‐ethylhexyl)sulphosuccinate] water‐in‐oil microemulsions at two different R‐values the Chromobacterium viscosum (CV) lipase and lipoprotein lipase ex Pseudomonas and to use them to catalyze the lactonization of 16‐hydroxyhexadecanoic acid at 40°C. CV lipase is also immobilized in gelatin‐containing microemulsion‐based gels (MBGs) with retention of catalytic activity. These lipase‐containing MBGs proved to be novel solid‐phase catalysts for use in apolar organic solvents. CV lipase‐containing MBGs are used to synthesize, on a preparative scale, a variety of different esters under mild conditions. [ABSTRACT FROM AUTHOR]

Front Cover: FeIII-Based Eutectic Mixtures as Multi-task and Reusable Reaction Media for Efficient and Selective Conversion of Alkynes into Carbonyl Compounds (Chem. Eur. J. 57/2023) Keywords: alkynes; atom economy; deep eutectic solvents; FeCl3-mediated organic synthesis; hydration EN alkynes atom economy deep eutectic solvents FeCl3-mediated organic synthesis hydration 1 1 1 10/18/23 20231013 NES 231013 B Thanks to the use b of a sustainable Fe SP III sp -based deep eutectic solvent ( I DES i ) as promoter/reaction medium, alkynes were hydrated under bench-type reaction conditions (45 °C, air, absence of co-catalysts or co-solvents). Alkynes, atom economy, deep eutectic solvents, FeCl3-mediated organic synthesis, hydration. [Extracted from the article]

Adaptation of all‐in‐one ionic systems with ionic liquids (ILs) serving as solvent, reactant, and catalyst is an innovative approach in the organic synthesis. Mild and bio clean choline based ILs as all‐in‐one systems (solvent, reagent, and catalyst) were developed via a simple metathesis approach and were applied on the ring‐opening reaction of epoxides. Sustained transformation of various epoxides using choline cyanide, azide, and hydroxide ILs delivered a neat, efficient and convenient protocol for the synthesis of β‐substituted alcohols in moderate to high yields (64‐97 %) with excellent activity and selectivity as confirmed by nuclear magnetic resonance (NMR) spectroscopic data. [ABSTRACT FROM AUTHOR]

In these environmentally conscious days there is need to use eco‐friendly greener technologies, such as solvent free, microwave, ultrasound and use of room temperature. Here report an efficient and green protocol for the synthesis of 5‐aminopyrazole‐4‐carbonitrile from three component condensation of phenyl hydrazine, aldehyde, and malononitrile using NaPTS as catalyst in aqueous medium. Use of water has emerged as a versatile solvent for organic reaction; it is readily available, inexpensive, environmentally benign, neutral and natural solvent. Multicomponent reactions in water are of outstanding value in organic synthesis and green chemistry. The significant features of this article are short reaction time, provide excellent yield, removal of toxic solvent and use of water as green solvent. [ABSTRACT FROM AUTHOR]

Designing reactions in aqueous media has been one of the major challenges in modern organic synthesis, especially to avoid the use of large amounts of organic solvents whose disposal is a matter of grave concern from an environmental perspective. The oxidation of alcohols and amines is an essential and important step in the synthesis of many valuable products including polymers and pharmaceuticals. In recent times, there has been a surge in the use of water as a solvent in many organic reactions. This review focuses specifically on the oxidation reactions of alcohols and amines carried out in water media using transition metal catalysts, metal‐free catalysts and photocatalysts. [ABSTRACT FROM AUTHOR]

The main objective of this study was to replace the traditionally applicable volatile organic solvents and imidazolium‐based ionic liquid solvents with thermally stable surfactant, cetylpyridinium bromide as surfactant ionic liquid (SIL) and examine the potential of the same as viable reaction medium in the synthesis of stilbenes, quinoxaline and pyridone decorated substrates via Heck cross‐coupling reaction. This work thoroughly investigates the thermal, spectral and morphological properties of cetylpyridinium bromide as surfactant ionic liquid. Cetylpyridinium bromide is a well‐known germicide with well‐established degradation mechanism and displays remarkable solvent properties for the homogeneously catalysed Heck cross‐coupling reactions, which is of great significance to enlarge the applications window of cetylpyridinium bromide from biologically significant surfactant material to the choice of solvent in synthetic organic chemistry. [ABSTRACT FROM AUTHOR]

A series of 8‐azacoumarin, naphthyridine, and dioxazphenalene derivatives bearing conjugated moieties were intended and prepared by a concise and smooth approach using grinding and ultrasonic irradiation. A sustainable one pot reactions have emerged and progressed smoothly as an efficient and eco‐safe methods in solvent less organic synthesis. The desired products were obtained in high yields, and the structures of all products were established on the basis of spectroscopic data and elemental analysis. Using the density functional theory (DFT) realized the electronic and structure characterization of synthesized azacoumarin. These heterocyclic compounds are chemically stable and are tested as antioxidants. Antioxidant potential was assessed using ABTS, and anti‐hemolytic activity was evaluated by induced peroxide hemolysis. They gave good antioxidant results that showed potency ranging from good azacoumarin analogues 8, 9, 13, 17, and 20, among compounds, showed much potency than that of commercial ascorbic acid. [ABSTRACT FROM AUTHOR]

In recent years, there has been an increasing tendency to use biocatalysts in industrial chemistry, especially in the pharma and fine chemical sector. Preferably, enzymes or whole cells, applied as catalysts for a specific biotransformation, are utilized in aqueous reaction media since water is the natural medium for enzymes. In numerous examples of biocatalytic systems, however, a major problem is the insolubility of hydrophobic substrates in such aqueous reaction media. Apart from lipases, many enzymes are highly sensitive to organic solvents and are inactivated by an organic medium. Therefore, a change of solvent for biotransformations from water to organic solvents is usually challenging. In this study, we investigated the synthesis of nitriles by an organic solvent‐labile aldoxime dehydratase in pure organic solvents, exemplified for the dehydration of n‐octanaloxime to n‐octanenitrile. We present a method for applications in batch as well as flow mode based on an "immobilized aqueous phase" bearing the whole cells in a superabsorber as solid phase, thus enabling the use of a purely organic solvent as "mobile phase" and reaction medium. [ABSTRACT FROM AUTHOR]

Organic synthesis without an organic solvent is still the exception. In this microreview, we discuss and compare different synthetic methods that proceed in the absence of conventional organic solvents. This includes solvent‐free methods in solids (mechanochemistry and solid‐state photochemistry), and in neat liquids (thermal and photocatalytic), as well as the application of unconventional solvents, such as ionic liquids and deep‐eutectic solvents. The different approaches are briefly introduced and examples illustrate their specific advantages, followed by a critical discussion of their limitations. Some methods have the intrinsic benefits of solvent‐free operation, such as avoiding solubility problems and side‐reactions with the solvent. However, every method has specific advantages and the demand of the synthetic application is crucial for selecting the best technique. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) acting as new functional solvents have significant impact in both synthetic and materials chemistry. However, the usage of volatile organic solvents in both synthesis and recycling of ILs usually imposes environmental issues. In this study, according to intrinsic wetting threshold theory, a membrane-based approach assisted by superwettability is developed for efficient, convenient, and economical purification of water-immiscible ILs. By precisely tailoring surface energy, the porous membrane is capable of hydrophobicity and superILphilicity (defined as IL contact angle close to zero), selectively allowing ILs to pass through. This kind of functional membrane can not only separate IL/water mixtures, but also IL/water systems containing inorganic salts, organic compounds, amino acids, and proteins. [ABSTRACT FROM AUTHOR]

This microreview summarizes the use of deep eutectic solvents (DESs) and related melts in organic synthesis. Solvents of this type combine the great advantages of other proposed environmentally benign alternative solvents, such as low toxicity, high availability, low inflammability, high recyclability, low volatility, and low price, avoiding many disadvantages of the more modern media. The fact that many of the components of these mixtures come directly from nature assures their biodegradability and renewability. The classification and distribution of the reactions into different sections in this microreview, as well as the emphasis paid to their scope, easily allow a general reader to understand the actual state of the art and the great opportunities opened, not only for academic purposes but also for industry. [ABSTRACT FROM AUTHOR]

Monovalent RAl (R = HC[C(Me)N(2,6-iPr2C6H3)]2) reacts with E2Et4 (E = Sb, Bi) with insertion into the weak E--E bond and subsequent formation of RAl(EEt2)2 (E = Sb 1; Bi 2). The analogous reactions of RGa with E2Et4 yield a temperature-dependent equilibrium between RGa-(EEt2)2 (E = Sb 3; Bi 4) and the starting reagents. RIn does not interact with Sb2Et4 under various reaction conditions, but formation of RIn(BiEt2)2 (5) was observed in the reaction with Bi2Et4 at low temperature. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) is a suitable tool for process intensification. For specialty chemicals production within a multi-purpose environment, there are some specific concerns regarding membranes and equipment design that have to be considered. Process development for OSN to date is hampered by a lack of system characteristics and detailed transport models. Here, we present a systematic investigation with different membrane materials and solvents in order to define guidelines for a fast membrane selection. [ABSTRACT FROM AUTHOR]

Here, we have utilized the incorporation of non-canonical amino acids as a tool kit to improve enzyme properties for organic synthesis applications. The global incorporation of 3-fluorotyrosine (FY) into ω-transaminase (ω-TA) to give ω-TA[FY] enhanced the thermostability and organic solvent tolerance without altering substrate specificity and enantioselectivity. Moreover, ω-TA[FY] was able to completely convert 25 mM of acetophenone into ( S)-1-phenylethylamine ( ee>99%) in the presence of 20% DMSO (v/v) which is ∼2-fold higher when compared to wild-type ω-TA. [ABSTRACT FROM AUTHOR]

Copper(II) acetate is frequently used as a catalyst for bond-forming reactions in organic synthesis. Unlike aqueous solutions, in which complete heterolysis to CuOAc+(aq) and AcO-(aq) prevails at low concentrations, it is clear that copper(II) acetate shows a large degree of aggregation in typical organic solvents. Here, the speciation behavior of Cu(OAc)2 in organic solvents is probed by electrospray ionization mass spectrometry (ESI-MS), which reveals an extensive clustering of copper acetate species to form ions of the general composition [Cu n(X)2 n-1]+ and [Cu n(X)2 n+1]- (X = OAc and OCH3), along with (solvated) monomeric species such as [Cu(OAc)(CH3OH) n]+. The ESI-MS measurements are complemented by solution-phase studies of Cu(OAc)2 by electron paramagnetic resonance spectroscopy, which support an extensive aggregation of Cu(OAc)2 in organic solvents. Collisional experiments reveal that either simple degradation or redox processes can be observed, depending on the coordinative saturation of the copper clusters. The formation of the copper clusters can be efficiently suppressed by contamination of the organic solvents by a small amount of water. [ABSTRACT FROM AUTHOR]

In this article, an efficient, environmentally benign, one-pot and simple synthesis of 2-aryl/heteroarylbenzothiazoles by the reaction of 2-aminothiophenol and aryl/heteroaryl aldehydes mediated by hypervalent iodine (III) reagents under solvent-free condition at room temperature is demonstrated. All the reactions were carried out by grinding the reactants (2-aminothiophenol and aryl/heteroaryl aldehydes) with hypervalent iodine (III) reagents in a mortar with pestle. Phenyliodine bistrifluoroacetate act as an efficient oxidizing reagent in comparison to iodobenzene diacetate in term of reaction time but yields are comparative. The advantages of this protocol are the one-step procedure, mild reaction conditions, high yields of the products, and no side reactions. [ABSTRACT FROM AUTHOR]

Trityl chloride (triphenylmethyl chloride, TrCl, Ph3CCl) is utilized as an efficient and homogeneous organocatalyst for the synthesis of 14-aryl-14 H-dibenzo[ a, j]xanthenes from β-naphthol and arylaldehydes under solvent-free conditions. Moreover, a plausible mechanism is suggested based on the literature and on in situ formation of trityl carbocation with inherent instability during the reaction. [ABSTRACT FROM AUTHOR]

Lewis acids catalyzed highly efficient one-pot three component coupling of β-naphthol, benzaldehydes and urea to produce 1-aryl-1,2-dihydro-naphtho[1,2-e][1,3]oxazin-3-one derivatives under solvent free conditions is described. Mechanistic studies confirmed that product formation is possible only at very high temperature (140-150°C) and at lower temperature (90-100°C) formation of 14-aryl-14 H-dibenzo(a,j)xanthenes was observed. Among the nine Lewis acids screened, iodine, P2O5 and Yb(OTf)3 are found to be most effective catalyst for this multicomponent reaction. [ABSTRACT FROM AUTHOR]

Chloroacylation reactions of cross-linked polystyrene (CPS) microspheres were conducted with two kinds of ω-chloroacyl chlorides, chloroacetyl chloride, and 4-chlorobutyryl chloride as reagent, respectively, and the chloromethylation reaction of CPS microspheres was also performed using 1,4-bis (chloromethoxy) butane as reagent, obtaining three kinds of modified CPS microspheres on which the exchangeable chlorine atoms were introduced. Subsequently, the reactions of these modified microspheres with triphenylphosphine were carried out, respectively, and three kinds of quaternary phosphonium salt (QPS)-type triphase catalysts (TPC) were prepared. These catalysts were used in the N-alkylation reaction of phthalimide, namely the reaction of phthalimide in water phase with 1-bromobutane in organic phase, resulting in N-butylphthalimide. The effects of main reaction conditions on the triphase-transfer catalysis reaction were examined, and the relationship between the structure and catalytic activity for these TPC was investigated. The experimental results indicate that the prepared QPS-type TPC are effective for the N-alkylation reaction of phthalimide carried out between oil phase and water phase. The polarity of the organic solvent and the temperature affect the reaction rate greatly. The result of the reaction in nitrobenzene having the highest polarity among the used several solvents is the best. It will make the reaction to speed up to raise temperature. The chemical structures of the TPC have crucial influences on the catalytic activity of the TPC. The catalyst with a longer spacer arm, which links the catalytic group to the matrix microspheres, has higher activity. The bonding density of QPS group on the polymer microspheres affects the hydrophilic and hydrophobic property of the TPC and, accordingly, affects the catalytic activity greatly. There is a maximum conversion of 1-bromobutane as the bonding density of QPS group on TPC is 0.94 mmol/g. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 677-686, 2011 [ABSTRACT FROM AUTHOR]

This paper describes the influence of the addition of ionic liquids (ILs) based on [BMIm][X], where [X] = SCN, Cl, BF4, and PF6, on the chemo-enzymatic oxidation of N-benzyliden-2-ethylhexylamine to form the corresponding E- and Z-isomers of oxaziridines mediated by Pseudomonas sp. (PSL) and Candida antarctica (CAL-B) lipases in various organic solvents at room temperature (25 °C) with urea hydrogen peroxide (UHP). The results showed that the use of different organic solvents in the presence of ILs, critically changes the conversions (5-99%) and the isomeric ratio E:Z, (50-100% E-isomer) of the products formed. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Phosphomolybdic acid PMA–SiO2was found to be an efficient catalyst for the threecomponent condensation reaction of phthalhydrazide, 1,3diketone, and aldehydes to produce 2Hindazolo1,2bphthalazinetriones in excellent yields. The catalyst can be recovered and reused without significant loss of activity. [ABSTRACT FROM AUTHOR]

Review: 106 refs. [ABSTRACT FROM AUTHOR]

Antibacterial activity is observed for new styrenesulfonamides (III) against Gram-positive Staphylococcus aureus, with compounds (IIIc,d) being the most effective ones. [ABSTRACT FROM AUTHOR]

Review: 110 refs. [ABSTRACT FROM AUTHOR]

Review: [82 refs. [ABSTRACT FROM AUTHOR]

This describes a series of high-yielding aqueous aldol reactions, some of them unachievable in organic solvents. [ABSTRACT FROM AUTHOR]

Use of molten Bu4NBr allows to carry out the reaction without any additional catalyst or organic solvent. [ABSTRACT FROM AUTHOR]