Search results for "combinatorial"

Efficient synthesis of copillar[5]arenes and their host–guest properties with dibromoalkanes

2011

An efficient method for the synthesis of copillar[5]arenes was developed with FeCl(3) as catalyst and different 1,4-dialkoxybenzenes and paraformaldehyde as reactants (yields: 50-85%). The host-guest property of (co)pillar[5]arenes and terminal dibromoalkanes was investigated by (1)H NMR measurements and an X-ray study. The complexation behavior of the copillar[5]arenes can be tuned by changing the substituents on the host. A complete complexation selectivity was found between pillar[5]- and pillar[6]arenes, which is an interesting aspect for sensor techniques.

Counteranion Effect on Complexation of Quats by a Neutral Calix[5]arene Receptor

2001

Studies of the synthesis of heterocyclic compounds. Part VII. The preparation of some new 3- and 5-amino-pyrazoles by endocyclicN-substitution of 3(5…

1982

By reaction of some 4-carbethoxy(or cyano)-3(5)-R-5(3)-aminopyrazoles 1 with 2-nitrobenzoyl chloride or 2-nitrobenzenesulfonyl chloride, a number of novel 3- and 5-amino-1-(2-nitrobenzoyl or 2-nitrobenzene-sulfonyl)pyrazoles 6 and 7 were obtained. Every compound appearing during the endocyclic N-substitution process can be identified and determined by glc. The use of nmr offers a rapid, unambigous method for determining the proposed structures.

Ferrocene-functionalized anilines as potent anticancer and antidiabetic agents: Synthesis, spectroscopic elucidation, and DFT calculations

2022

Abstract Ferrocene derivatives have attracted significant interest as potent biological agents and novel drug candidates. Hence, the present research work was focused on the synthesis and characterization of ferrocene-integrated anilines (FB1-FB4) through different spectroscopic techniques such as: FT-IR, multinuclear (1H and 13C) NMR, Raman, atomic absorption spectroscopy, elemental analysis, and single-crystal X-ray crystallography. The crystallographic analysis revealed a supramolecular structure mediated by secondary non-covalent interactions (π—H and π—π). These ferrocenyl derivatives demonstrated a quasi-reversible electrochemical behavior with one electron transfer from Fe(II) to Fe(…

ChemInform Abstract: Chemical and Enzymic Synthesis of Glycopeptides

2010

ChemInform Abstract: O- and N-Glycopeptides: Synthesis of Selectively Deprotected Building Blocks

2010

ChemInform Abstract: (-)-Isosteviol as a Versatile Ex-Chiral-Pool Bulding Block for Organic Chemistry

2013

Asymmetric Synthesis of Dihydropyranones with Three Contiguous Stereocenters by an NHC‐Catalyzed Kinetic Resolution

2021

An oxidative NHC-catalyzed kinetic resolution (KR) of racemic mixtures is presented. The developed reaction furnishes tricyclic dihydropyranones with three contiguous stereocenters in excellent dia- and enantioselectivity, with good-to-moderate yields. Mechanistic studies indicate that the rate-determining step of the reaction is the formation of the Breslow intermediate, while the selectivity determining step occurs later in the mechanism. The presented methodology enables rapid synthesis of complex structures in a single step.

Catalysis in Supramolecular Systems: the Case of Gel Phases

2021

Supramolecular gels are a fascinating class of materials, originated by the self-assembly of low molecular weight molecules. Underpinned by non-covalent interactions, they find application in a diverse range of fields. Among these, supramolecular gels can be considered as organized, non-conventional reaction media, able to influence reactivity in a radically different way, compared with what happens in solution. This short review will focus on this aspect, covering literature from 2010 onwards, addressing the application of supramolecular gels as reaction media. In particular, in the first section we explore organocatalytic reactions in gel phase, with wide synthetic relevance, such as aldo…

ChemInform Abstract: Synthesis of Highly Functionalized 9,10-Phenanthrenequinones by Oxidative Coupling Using MoCl5.

2012

An efficient method to prepare functionalized 9,10-phenanthrenequinones including the natural cypripediquinone A (VIIIa) is reported.