Search results for "SURFACE MODIFICATION"

Functionalization with silyl enol ethers, VI Zinc chloride mediated alkoxyalkylation of O-methyl-O-trimethylsilyl) keten acetals with 2-alkoxy-1,3-di…

1987

O-Methyl-O-(trimethylsilyl) keten acetals2 were regioselectively alkoxyalkylated by 2-alkoxy-1,3-dioxolanes1 in the presence of zinc chloride. This method represents a good way for synthesis of α-protected β-keto carbonic esters4.

ChemInform Abstract: Approaches for the Introduction of Fluorinated Substituents into [1,2,3]Triazolo[1,5-a]pyridines.

2014

Functionalization of [1,2,3]triazolo[1,5-a]pyridines with a trifluoromethyl group is achieved for the first time.

Recent Advances in the Synthesis of Piperidines: Functionalization of Preexisting Ring Systems

2018

Abstract The present review focuses on strategies for the construction of piperidines which have appeared in the literature since 2003 through mid-2017. In a preceding chapter ( 2017AHC191 ), we summarized synthetic methods involving the construction of the piperidine ring from essentially acyclic starting materials in an intra- or intermolecular manner. The present chapter aims at giving a general overview of decoration or modification of previously generated pyridines or piperidines. The hydrogenation of preformed pyridine or pyridinium rings and introduction of substituents into fully saturated piperidines as well as ring expansion of pyrrolidines to piperidines are the most prevalent me…

Photoinduced functionalization of the C-20 methyl group of the nor-diterpene atractyligenin

2001

Abstract Irradiation of the nor-diterpene atractyligenin at λ =254 nm in methanol gave, on one hand, the decarboxylation product, and provided, on the other hand, the transformation of the C-20 angular methyl into a methylene-carbomethoxy group. A photochemical pathway involving formation of C-19/C-20 bond is suggested.

Surface modification of graphite+polymer composite and ITO electrodes by Nafion®+cupromeronic phthalocyanine films

1999

Abstract The surface of indium tin oxide (ITO) and graphite+polymer composite electrodes can be modified by Nafion ® films containing a little amount of dispersed electroactive substances, such as phthalocyanines. This procedure allows the recovery of electroanalytical information on the electroactive deposited substance. The preparation methods for these types of modified electrodes are discussed from the voltammetric results obtained in this work. The Nafion ® net acts as a permeable membrane to the hydrogen ions. Furthermore, the presence of methylviologen within the Nafion ® film makes the electron transport throughout this membrane easy.

ChemInform Abstract: Functionalization of 2-(1-Naphthyl)-5-phenyl-1,3,4-oxadiazole with Alkoxysilanes.

2010

ChemInform Abstract: Boron Functionalization of BODIPY by Various Alcohols and Phenols

2014

The synthesis of new B–O BODIPY derivatives functionalized with different alkoxy or diarylalkoxy derivatives is described. These compounds were synthesized from the reaction of different B–F BODIPY precursors with various alcohols and phenols, in the presence of AlCl3. Water-soluble dyes could be synthesized as well with this method, specifically by the introduction of polyethyleneglycol (PEG) groups. A photophysical study of the different compounds was performed, and showed that the B–O BODIPY derivatives exhibit rich fluorescence properties. Finally, the conjugation of the BODIPY core has been extended using two distyryl groups, hence providing NIR emitting BODIPY derivatives, in which on…

Synthesis of novel fluorinated building blocks via halofluorination and related reactions.

2020

A study exploring halofluorination and fluoroselenation of some cyclic olefins, such as diesters, imides, and lactams with varied functionalization patterns and different structural architectures is described. The synthetic methodologies were based on electrophilic activation through halonium ions of the ring olefin bonds, followed by nucleophilic fluorination with Deoxo-Fluor®. The fluorine-containing products thus obtained were subjected to elimination reactions, yielding various fluorine-containing small-molecular entities.

Functionalization of nanoparticles in specific targeting and mechanism release

2017

The development of various nanotechnologies have provided a new field of research, which allows the manipulation of molecular components of matter and covers a vast array of nanodevices. The “smart” multifunctional nanostructures should work as customizable, targeted drug-delivery vehicles capable of carrying large doses of therapeutic agents into malignant cells. Some nanomedical approaches are based on the use of functionalized nanoparticles (NPs), not only to reduce toxicity and side effects of drugs but, also in potential the biological barriers crossing on, such as: the blood–brain barrier, different cellular compartments, including the nucleus. Currently, many materials are used for n…

Carbohydrate-Based Nanocarriers Exhibiting Specific Cell Targeting with Minimum Influence from the Protein Corona.

2015

Whenever nanoparticles encounter biological fluids like blood, proteins adsorb on their surface and form a so-called protein corona. Although its importance is widely accepted, information on the influence of surface functionalization of nanocarriers on the protein corona is still sparse, especially concerning how the functionalization of PEGylated nanocarriers with targeting agents will affect protein corona formation and how the protein corona may in turn influence the targeting effect. Herein, hydroxyethyl starch nanocarriers (HES-NCs) were prepared, PEGylated, and modified on the outer PEG layer with mannose to target dendritic cells (DCs). Their interaction with human plasma was then s…