Derivatives In Organic Synthesis Research Articles

N-Heteroocyclic Carbenes and N-Heterocycles as Synthetic Reagents and Building Blocks.

N-Heterocyclic carbenes (NHCs) have become important tools in modern synthetic chemistry due to their versatility as organocatalysts and ligands in organometallic complexes. Since their first isolation and characterization, NHCs have demonstrated significant utility in various catalytic processes, offering advantages such as strong σ-electron donation and the ability to stabilize reactive intermediates. However, beyond their well-documented roles in catalysis, the potential of NHCs as stoichiometric reagents and synthetic building blocks remains an underexplored yet promising area. This Mini-review aims to shed light on these lesser-known applications of NHCs and their N-heterocyclic precursors or derivatives in organic synthesis. Furthermore, we discuss how the unique electronic and steric properties of NHCs can be harnessed to develop new synthetic methodologies or construct interesting organic frameworks. By highlighting these emerging uses, we hope to encourage further research into the non-catalytic applications of NHCs, broadening their scope and impact in synthetic chemistry.

Synthesis, Molecular Docking Analysis and In vitro Evaluation of 1,4- Dihydroxyanthraquinone Derivatives As Anti-Trypanosomal Agents

Abstract: Hydroxy-substituted anthraquinones are among the most important derivatives in organic synthesis. The attractive biological properties of these compounds are relevant to many therapeutic areas that are of use in clinical applications. In this study synthesized several amino-substituted anthraquinones were synthesized from 1,4-dihydroxyanthraquinone using a modified Marschalk reaction. Moreover, 1,4,5-trihydroxyanthraquinone was synthesized from anacardic acid, an agro-waste from the cashew industry. The in-vitro screening of the compounds against Trypanosoma brucei parasites revealed noteworthy activity with reasonable selectivity against human cell lines. A molecular docking study was performed to analyze the synthesized compounds' modes of interaction to the trypanothione reductase's active site. Visual inspections examined the docked poses, and test compounds displayed a good binding affinity with the receptor protein. This in vitro/ molecular docking evaluation suggests that substituted 1,4-dihydroxyanthraquinone derivative can be promising starting structures in the search for active drugs against trypanosomiasis.

Applications of 3,5‐Dialkyl‐4‐nitroisoxazoles and Their Derivatives in Organic Synthesis#

AbstractThe methyl/methylene group present at the 5th position of 3,5‐dialkyl‐4‐nitroisoxazoles show characteristic reactivity because of the presence of −NO2 at the 4th position in the structure. This methyl/methylene is used for the generation of carbanion that undergo Knoevenagel condensation, vinylogous nitroaldol (Henry type), Mannich and Michael addition reactions. The unsaturated systems generated by Knoevenagel condensation are used for 1,4‐ and 1,6‐Michael addition, epoxidation, aziridination, cycloaddition ([2+1], [2+2], [2+3] and [4+2]) cascade/domino/tandem and dihydroxylation reactions. This resulted into the generation of many functionalized and complex organic molecules in asymmetric and racemic forms. Along with these, the isoxazole moiety has also been used as −COOH equivalent by basic/oxidative hydrolysis. This review describes recent literature on the synthetic applications of 3,5‐dialkyl‐4‐nitroisoxazoles and their derivatives for the generation of functionalized/complex heterocyclic compounds using above mentioned type of reactions and concepts.

Sequential Acylation/Silylation/Hetero‐Claisen Rearrangement of Nitroalkanes for the Synthesis of Protected Hydroxyoxime Derivatives

AbstractSequential acylation‐silylation of nitroalkanes leads to O‐silylated α‐acyloxyoximes in high yields. The first step of the reaction involves deprotonation of nitro compound with sodium hydride promoted by DBU or alcohol/15‐crown‐5 system followed by treatment with acyl chloride. In situ generated acyl nitronate is further silylated by silyl triflate that triggers hetero‐Claisen [3,3]‐rearrangement within N‐acyloxyenamine moiety furnishing orthogonally protected oxime derivatives. The procedure has large substrate scope for both nitroalkanes and acylating agents (acyl chlorides, chloroformates) and allows tuning of reaction conditions depending on the particular type of substrate. Application of obtained oxime derivatives in organic synthesis is demonstrated.

Acridinium Salts and Cyanoarenes as Powerful Photocatalysts: Opportunities in Organic Synthesis

AbstractThe use of organic photocatalysts has revolutionized the field of photoredox catalysis, as it allows access to reactivities that were traditionally restricted to transition‐metal photocatalysts. This Minireview reports recent developments in the use of acridinium ions and cyanoarene derivatives in organic synthesis. The activation of inert chemical bonds as well as the late‐stage functionalization of biorelevant molecules are discussed, with a special focus on their mechanistic aspects.

Acridinium Salts and Cyanoarenes as Powerful Photocatalysts: Opportunities in Organic Synthesis.

The use of organic photocatalysts has revolutionized the field of photoredox catalysis, as it allows access to reactivities that were traditionally restricted to transition-metal photocatalysts. This Minireview reports recent developments in the use of acridinium ions and cyanoarene derivatives in organic synthesis. The activation of inert chemical bonds as well as the late-stage functionalization of biorelevant molecules are discussed, with a special focus on their mechanistic aspects.

The Molecular Diversity Scope of Oxindole Derivatives in Organic Synthesis

The role of oxindole derivatives is discussed as starting materials in diverse organic reactions, including two and more components, between the years 2014 until 2020. Oxindoles are famous because of their biological properties. For instance, chromanone-fused polycyclic pyrrolidinyl-dispirooxindoles, functionalized polycyclic spiro-fused carbocyclicoxindole, and 3,3-disubstituted oxindoles have anti-cancer, anti-tumor, and anti-microbial properties, respectively. Therefore, various methods for synthesizing the oxindole structures have received much attention in organic chemistry.

The Molecular Diversity Scope of Oxindole Derivatives in Organic Synthesis

Bentham Science - STM publisher of online and print journals, and related print/online book series. Bentham Science answers the information needs of scientists in the fields of pharmaceutical, biomedical, medical, engineering, technology, computer and social sciences.

Photocatalytic α-Tertiary Amine Synthesis via C-H Alkylation of Unmasked Primary Amines.

A practical, catalytic entry to α,α,α‐trisubstituted (α‐tertiary) primary amines by C−H functionalisation has long been recognised as a critical gap in the synthetic toolbox. We report a simple and scalable solution to this problem that does not require any in situ protection of the amino group and proceeds with 100 % atom‐economy. Our strategy, which uses an organic photocatalyst in combination with azide ion as a hydrogen atom transfer (HAT) catalyst, provides a direct synthesis of α‐tertiary amines, or their corresponding γ‐lactams. We anticipate that this methodology will inspire new retrosynthetic disconnections for substituted amine derivatives in organic synthesis, and particularly for challenging α‐tertiary primary amines.

Photocatalytic α‐Tertiary Amine Synthesis via C−H Alkylation of Unmasked Primary Amines

AbstractA practical, catalytic entry to α,α,α‐trisubstituted (α‐tertiary) primary amines by C−H functionalisation has long been recognised as a critical gap in the synthetic toolbox. We report a simple and scalable solution to this problem that does not require any in situ protection of the amino group and proceeds with 100 % atom‐economy. Our strategy, which uses an organic photocatalyst in combination with azide ion as a hydrogen atom transfer (HAT) catalyst, provides a direct synthesis of α‐tertiary amines, or their corresponding γ‐lactams. We anticipate that this methodology will inspire new retrosynthetic disconnections for substituted amine derivatives in organic synthesis, and particularly for challenging α‐tertiary primary amines.

Catalytic Applications of Saccharin and its Derivatives in Organic Synthesis

: Saccharin (1,2-benzisothiazol-3(2H)-one-1,1-dioxide) is a very mild, cheap, commercially available, water soluble, environmentally benign and edible Brønsted acidic substance. Recently, with other utilities, saccharin and its derivatives were employed as catalysts for various organic transformations. In this review, catalytic applicability of saccharin and its derivatives under various reaction conditions is summarized.

Thermodynamic Parameters of Elementary Steps for 3,5-Disubstituted 1,4-Dihydropyridines To Release Hydride Anions in Acetonitrile.

A series of 3,5-disubstituted 1,4-dihydropyridine derivatives including the derivative with two chiral centers, 6H (R2 = CH3, CH2Ph), as a new type of organic hydride source were synthesized and characterized. The thermodynamic driving forces (defined as enthalpy changes or standard redox potentials) of the 6 elementary steps for the organic hydrides to release hydride ions in acetonitrile were measured by isothermal titration calorimetry and electrochemical methods. The impacts of the substituents and functional groups bearing the N1 and C3/C5 positions on the thermodynamic driving forces of the 6 elementary steps were examined and analyzed. Moreover, the results showed that the reaction mechanism between the chiral organic hydride and activated ketone (ethyl benzoylformate) was identified as the concerted hydride transfer pathway based on the thermodynamic analysis platform. These valuable and crucial thermodynamic parameters will provide a broadly beneficial impact on the applications of 3,5-disubstituted 1,4-dihydropyridine derivatives in organic synthesis and pharmaceutical chemistry.

Applications of TEMPO in Synthesis

This review describes the broad application of TEMPO and its derivatives in organic synthesis. Various reactions including oxidation of alcohols, sulfides and organometallic compounds are discussed. Moreover, the use of TEMPO as a stoichiometric or catalytic cooxidant in various transition-metal-mediated reactions is presented. The application of TEMPO as a carbon-radical trapping reagent in cascade reactions is discussed. Finally, the review article focuses on the application of TEMPO-derived alkoxyamines as thermal carbon-radical precursors in synthesis and in polymer chemistry.

ChemInform Abstract: Dehydroacetic Acid and Its Derivatives in Organic Synthesis: Synthesis of Some New 2‐Substituted‐4‐ (5‐bromo‐4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one‐3‐yl)thiazoles.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis and Reactivity of Azidoalkylphosphonates, -Phosphinates and -Phosphine Oxides

This review will focus on the synthesis of α- and β-azidoalkylphosphonic and -phosphinic acids, -phosphine oxides and their derivatives as well as their reactions utilizing the azido group and/or phosphyl group. In the first part of this review synthetic routes to such azides will be reviewed. Generally, these compounds are achieved via nucleophilic substitution of hydroxy derivatives of phosphonates, -phosphinates, and -phosphine oxides by the Mitsunobu protocol or by the displacement of their sulfonates or halogen derivatives with azides. The ring-opening of phosphorus-containing oxiranes or cyclic vicinal sulfates with azides will also be discussed. Electrophilic azidation of the corresponding phosphorus- stabilized carbanions has also been described. In the second part of the review emphasis will be placed on the application of azido derivatives in organic synthesis. 1,3-Dipolar cycloaddition is an excellent tool in the construction of fivemembered heterocycles. Therefore, the formation of 1,2,3-triazoles from alkynes, enamines and 2-oxoalkylidenetriphenylphosphoranes will be discussed. Hence, the azido group is easily converted into amine, and phosphorus-containing azides can be considered to be azide-masked equivalents of amino derivatives or their N-protected derivatives. The application of such azides in the synthesis of phosphorus analogs of amino acids will be discussed. The synthesis of carbodiimides, imines, isothiocyanates and phosphonodipeptides has also been reviewed.

The Application of Cyclobutane Derivatives in Organic Synthesis

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Recent Applications of 2,4,6‐Trichloro‐1,3,5‐triazine and Its Derivatives in Organic Synthesis

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Recent Advances in the Use of Tri(2‐furyl)germane, Triphenylgermane and Their Derivatives in Organic Synthesis

AbstractFor Abstract see ChemInform Abstract in Full Text.

Silicon—Mercury Derivatives in Organic Synthesis

AbstractFor Abstract see ChemInform Abstract in Full Text.

Recent Uses of Bismuth Derivatives in Organic Synthesis

AbstractFor Abstract see ChemInform Abstract in Full Text.