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Direct Functionalization (direct + functionalization)

Distribution by Scientific Domains
Polymers and Materials Science57%
Chemistry42%

Selected Abstracts

ChemInform Abstract: Direct Functionalization of Benzoquinolines.

CHEMINFORM, Issue 28 2010
Victor Mamane
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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. [source]

Direct Functionalization of Arenes by Primary Alcohol Sulfonate Esters Catalyzed by Gold(III).

CHEMINFORM, Issue 9 2005
Zhangjie Shi
No abstract is available for this article. [source]

Direct functionalization of polyisobutylene by living initiation with ,-methylstyrene epoxide

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2002
J. Song
Abstract This article describes the synthesis and characterization of polyisobutylene (PIB) carrying one primary hydroxyl head group and a tertiary chloride end group, [PhC(CH3)(CH2OH),PIB,CH2C(CH3)2Cl] prepared with direct functionalization via initiation. The polymerization of isobutylene was initiated with the ,-methylstyrene epoxide/titanium tetrachloride system. Living conditions were obtained from ,75 to ,50 °C (198,223 K). Low molecular weight samples (number-average molecular weight , 4000 g/mol) were prepared under suitable conditions and characterized by Fourier transform infrared and 1H NMR spectroscopy. The presence of primary hydroxyl head groups in PIB was verified by both methods. Quantitative Fourier transform infrared with 2-phenyl-1-propanol calibration and 1H NMR performed on both the hydroxyl-functionalized PIB and its reaction product with trimethylchlorosilane showed that each polymer chain carried one primary hydroxyl head group. The synthetic methodology presented here is an effective and simple route for the direct functionalization of PIB. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1005,1015, 2002 [source]

Functionalization Strategies for Protease Immobilization on Magnetic Nanoparticles

ADVANCED FUNCTIONAL MATERIALS, Issue 11 2010
Dan Li
Abstract A comprehensive study on the general functionalization strategies for magnetic nanoparticles (MNPs) is presented in this work. Using well-established techniques as well as modified protocols, the wide range of functional moieties grafted on ,-Fe2O3 (maghemite) nanosurfaces include those of amine, aldehyde, carboxylic, epoxy, mercapto, and maleimide ends. Among the modified protocols are the one-step water-catalyzed silanization with mercaptopropyltrimethoxysilane, resulting in dense distal thiols, and the direct functionalization with a heterogeneous bifunctional linker N -[p-maleimidophenyl]isocynanate (PMPI). The former results in a protective Stöber type coating while simultaneously reducing the iron oxide core to magnetite (Fe3O4). The conjugation of trypsin, hereby chosen as model biomolecule, onto the differently functionalized MNPs is further demonstrated and assessed based on its activity, kinetics, and thermo-/long-term stability as well as reusability. Besides aqueous stability and ease in recovery by magnetic separation, the immobilized trypsin on MNPs offers superior protease durability and reusability, without compromising the substrate specificity and sequence coverage of free trypsin. The MNP-based proteases can be used as valuable carriers in proteomics and miniaturized total analysis devices. The applicability of the functional surfaces devised in the current study is also relevant for the conjugation of other biomolecules beyond trypsin. [source]

Precision synthesis and characterization of thymine-functionalized polyisobutylene

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 16 2010
Mustafa Y. Sen
Abstract A new two-step synthesis of polyisobutylene (PIB) with precisely one thymine functionality per chain (PIB-T) is reported. The primary hydroxyl-functionalized PIB (PIB-OH) precursor was prepared by direct functionalization via living carbocationic polymerization of isobutylene initiated by the ,-methylstyrene epoxide/TiCl4 system. Matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) of a low molecular weight PIB-OH precursor demonstrated the effectiveness of direct functionalization by this method. A PIB-acrylate precursor (PIB-Ac) was obtained from such a PIB-OH, and the PIB-T was subsequently prepared by Michael addition of thymine across the acrylate double bond. MALDI-ToF MS of the products verified that all polymer chains carried precisely one thymine group. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3501,3506, 2010 [source]

Direct functionalization of polyisobutylene by living initiation with ,-methylstyrene epoxide

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2002
J. Song
Abstract This article describes the synthesis and characterization of polyisobutylene (PIB) carrying one primary hydroxyl head group and a tertiary chloride end group, [PhC(CH3)(CH2OH),PIB,CH2C(CH3)2Cl] prepared with direct functionalization via initiation. The polymerization of isobutylene was initiated with the ,-methylstyrene epoxide/titanium tetrachloride system. Living conditions were obtained from ,75 to ,50 °C (198,223 K). Low molecular weight samples (number-average molecular weight , 4000 g/mol) were prepared under suitable conditions and characterized by Fourier transform infrared and 1H NMR spectroscopy. The presence of primary hydroxyl head groups in PIB was verified by both methods. Quantitative Fourier transform infrared with 2-phenyl-1-propanol calibration and 1H NMR performed on both the hydroxyl-functionalized PIB and its reaction product with trimethylchlorosilane showed that each polymer chain carried one primary hydroxyl head group. The synthetic methodology presented here is an effective and simple route for the direct functionalization of PIB. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1005,1015, 2002 [source]

A Versatile Catalyst for Intermolecular Direct Arylation of Indoles with Benzoic Acids as Arylating Reagents

CHEMISTRY - A EUROPEAN JOURNAL, Issue 20 2010
Jun Zhou
Coupled together: With a versatile catalyst system (Pd(TFA)2/Ag2CO3/propionic acid) both electron-rich and -deficient benzoic acids serve as arylating reagents for the direct functionalization of a wide rage of indoles by a combination of decarboxylation and CH bond activation. Depending on the nature of the benzoic acids, the reaction occurs selectively at either the C2- or C3-position of indoles, which may arise from two different catalytic pathways (see scheme; TFA=trifluoroacetate). [source]