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Peptidomimetics are a privileged class of pharmacophores that exhibit improved physicochemical and biological properties. Solid-phase synthesis is a powerful tool for gaining rapid access to libraries of molecules from small molecules to biopolymers and also is widely used for the synthesis of peptidomimetics. Small molecules including heterocycles serve as a core for hundreds of drugs, including peptidomimetic molecules. This review covers solid-phase synthesis strategies for peptidomimetics molecules based on heterocycles.

The human gastrointestinal tract houses an enormous microbial ecosystem. Recent studies have shown that the gut microbiota plays significant physiological roles and maintains immune homeostasis in the human body. Dysbiosis, an imbalanced gut microbiome, can be associated with various disease states, as observed in infectious diseases, inflammatory diseases, autoimmune diseases, and cancer. Modulation of the gut microbiome has become a therapeutic target in treating these disorders. Fecal microbiota transplantation (FMT) from a healthy donor restores the normal gut microbiota homeostasis in the diseased host. Ample evidence has demonstrated the efficacy of FMT in recurrent Clostridioides difficile infection (rCDI). The application of FMT in other human diseases is gaining attention. This review aims to increase our understanding of the mechanisms of FMT and its efficacies in human diseases. We discuss the application, route of administration, limitations, safety, efficacies, and suggested mechanisms of FMT in rCDI, autoimmune diseases, and cancer. Finally, we address the future perspectives of FMT in human medicine. [ABSTRACT FROM AUTHOR]

New tricyclic benzimidazoles have been synthesized by condensation of 3,4‐dihydro‐2H‐benzo[b][1,4]oxazin‐5‐amine and different aldehydes in presence of sodium metabisulfite adsorbed on silica. The method is very efficient, and reactions are completed at room temperature with easy product isolation. The synthesized compounds showed antimicrobial potential against gram‐positive bacteria S. aureus and gram‐negative bacteria E. coli with MIC of 0.625 mg/ml for compounds 6 f (cyclohexyl substituent) and 6 h (furan substituent) and 0.312 mg/ml for compound 6 c (chlorophenyl substituent) respectively, were evaluated by Resazurin microtiter plate visual method. Molecular docking studies using Autodock 4.2 showed theoretical binding energy −6.74 to −8.32 Kcal/mol for S. aureus and −5.94 to −8.01 Kcal/mol for E. coli with PDB Id 2W9S and 2EX6 respectively. [ABSTRACT FROM AUTHOR]

Peptidomimetics are a class of compounds with promising pharmacological properties. Peptidomimetics reduce limitations of peptides including low bioavailability, poor stability, and poor cell‐permeability. Peptide backbone modifications are a frequently used manipulation to reach desirable properties of the peptide molecules. The development of accessible synthetic methodologies plays an important role in peptidomimetic progress. Synthesis of peptidomimetics proceeds via solution and solid‐phase synthesis strategies. Solid‐phase organic synthesis serves as a powerful tool for the preparation of peptidomimetic molecules, thus, numerous strategies have been developed over the years. In this review, we discuss solid‐phase synthetic approaches for peptide backbone modifications that were presented in the last two decades. [ABSTRACT FROM AUTHOR]

Carbocations have played a central role in the chemical sciences for over a century. In a synthetic setting, most methods utilize stabilized tricoordinate carbocations, while there are far fewer examples of reactions featuring nonstabilized dicoordinate cations. Here, we provide an overview of recent developments in the generation of high-energy carbocations mediated by weakly coordinating anions and the C–H insertion reactions of such carbocations. Moreover, we discuss mechanistic studies of these catalytic C–H insertion reactions aimed at furthering our understanding of the reactive nature of these rarely invoked cationic intermediates. 1 Introduction 2 Background: Phenyl Carbocations 3 Silylium/Carborane-Catalyzed C–H Insertion Reactions of Phenyl Carbocations 4 Silane-Fueled, Weakly Coordinating Anion-Catalyzed, Reductive C–H Insertion Reactions of Vinyl Carbocations 5 C–H Insertion Reactivity of Vinyl Carbocations under Basic Conditions 6 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

High on cycloaddi(c)tions: The impact of the Woodward–Hoffmann [4n+2] rule for thermally allowed cycloaddition reactions and the challenges associated with moving from six to ten electrons are discussed in this Essay. [ABSTRACT FROM AUTHOR]

Sisyphus ‐ Arbeit: Die Bedeutung der Woodward ‐ Hoffmann ‐ [4n+2] ‐ Regel für thermisch erlaubte Cycloadditionen und die Herausforderungen, die mit dem Übergang von sechs zu zehn Elektronen einhergehen, werden in diesem Essay diskutiert. [ABSTRACT FROM AUTHOR]

A variety of quinoline-4-amines were synthesized from substituted 3-(2-nitrophenyl)isoxazoles utilizing Zn0 or Fe0 dust and HOAc using a reductive heterocyclization process. The starting isoxazoles were synthesized from readily available starting materials. A brief survey of functional groups tolerated in this reductive heterocyclization was performed and several 10-amino-3,4-dihydrobenzo[ b][1,6]naphthyridin-1(2 H)-one and 9-amino-3,4-dihydroacridin-1(2 H)-one examples were synthesized. [ABSTRACT FROM AUTHOR]

Peptidomimetics are a privileged class of pharmacophores that exhibit improved physicochemical and biological properties. Solid-phase synthesis is a powerful tool for gaining rapid access to libraries of molecules from small molecules to biopolymers and also is widely used for the synthesis of peptidomimetics. Small molecules including heterocycles serve as a core for hundreds of drugs, including peptidomimetic molecules. This review covers solid-phase synthesis strategies for peptidomimetics molecules based on heterocycles. [ABSTRACT FROM AUTHOR]