نتایج جستجو برای: ugi reaction
تعداد نتایج: 412882 فیلتر نتایج به سال:
Isocyanide-based multicomponent reactions (IMCR) are by far the most versatile reactions that can construct relatively complex molecules by one-pot synthesis. More importantly, the development of post IMCR modifications significantly improves the scaffold's diversity. Here, we describe the use of N-Boc protected hydrazine together with α-amino acid derived isocyanides in the Ugi tetrazole react...
A focused library of virtual heterobifunctional ligands was generated in silico and a set of ligands with recombined fragments was synthesized and evaluated for binding to Clostridium difficile toxins. The position of the trisaccharide fragment was used as a reference for filtering docked poses during virtual screening to match the trisaccharide ligand in a crystal structure. The peptoid, a div...
An alternative approach toward the simple and robust synthesis of highly substituted peptidic thiazole derivatives using Ugi-multicomponent reaction (U-MCR) is described. Thus, we introduced the enantiopure (R)-2-methyl-2-isocyano-3-(tritylthio)propanoate as a novel class of isocyanide in MCR. This bifunctional isocyanide was found to undergo mild cyclodehydration to afford thiazole containing ...
The first chiral catalyst for the three-component Ugi reaction was identified as a result of a screen of a large set of different BOROX catalysts. The BOROX catalysts were assembled in situ from a chiral biaryl ligand, an amine, water, BH3·SMe2, and an alcohol or phenol. The catalyst screen included 13 different ligands, 12 amines, and 47 alcohols or phenols. The optimal catalyst system (LAP 8-...
Amine precursors such as NH-Boc (5) and NH-formyl (6) protected glycines were grafted by esterification on the hy-droxylated arms of 1-(2-hydroxyethyl)-3-methylimidazolium hexafluorophosphates 4h or tetrafluoroborates 4t. The Boc cleav-age was then realized at room temperature by successively treating acetonitrile solutions of the carbamates 7h or 7t with methanol and acetyl chloride (2 equival...
Chlorination-elimination chemistry coupled with three-component Joullié-Ugi reaction and facile deprotection allowed efficient access to an array of polyhydroxylated pyrrolidines through parallel synthesis that may be considered to be a library of imino (aza) sugars (glycomimetics) and/or dihydroxyprolyl peptides (peptidomimetics). The utility of generating such a library was illustrated by scr...
A miniaturised-SYNthesis and Total Analysis System (μSYNTAS) integrating a silicon-machined chemical microprocessor and time-of-flight mass spectrometry (TOF-MS) is used for the generation of compound libraries based on sub-reactions of an Ugi multicomponent reaction (MCR). The microreactor—based on the concept of an AND logic operator—allowed the coupling of serially-switched solution-phase li...
Based on a combination of an Ugi four component reaction and a ring closing metathesis, a library of novel artificial macrocyclic inhibitors of the p53-MDM2 interaction was designed and synthesized. These macrocycles, alternatively to stapled peptides, target for the first time the large hydrophobic surface area formed by Tyr67, Gln72, His73, Val93, and Lys94 yielding derivatives with affinity ...
Background and Objective: To assess the incidence and risk factors of upper gastrointestinal bleeding in children admitted to pediatric intensive care unit for more than 6 hrs. Methods: We prospectively collected medical records of children between 1 month and 18 years old admit-ted to our 10 bed PICU of a tertiary care university hospital between December 1, 2014 and May 30, 2015. De-mographi...
The synthesis of novel peptide conjugates of N-substituted-tetrahydro-γ-carbolines has been performed using the sequence of the Ugi multicomponent reaction and Cu(I)-catalyzed click chemistry. The effect of obtained γ-carboline-peptide conjugates on the rat liver mitochondria was evaluated. It was found that all compounds in the concentration of 30 µM did onot induce depolarization of mitochond...
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