نتایج جستجو برای: functionalization

تعداد نتایج: 9962  

2014
Vaibhav P Mehta José-Antonio García-López Michael F Greaney

Three orthogonal cascade CH functionalization processes are described, based on ruthenium-catalyzed CH alkenylation. 1-Indanones, indeno indenes, and indeno furanones were accessed through cascade pathways by using arylacetophenones as substrates under conditions of catalytic [{Ru(p-cymene)Cl2 }2 ] and stoichiometric Cu(OAc)2 . Each transformation uses CH functionalization methods to form C...

Journal: :Chimia 2011
Nando Gartmann Dominik Brühwiler

Most applications of mesoporous silica require some degree of functionalization. The surface of porous materials can be divided into external and internal (pore) surfaces, and in many cases, a selective functionalization of these surface subsections is desired. This short review outlines our recent work in this field and focuses on the postsynthetic functionalization of mesoporous silica with a...

2014
Will R. Gutekunst Phil S. Baran

The application of C-H functionalization logic to target-oriented synthesis provides an exciting new venue for the development of new and useful strategies in organic chemistry. In this article, C-H functionalization reactions are explored as an alternative approach to access pseudodimeric cyclobutane natural products, such as the dictazole and the piperarborenine families. The use of these str...

2017
José Miguel Escolano Teona Mirea Jimena Olivares Marta Clement Diego Megias Enrique Iborra

In this work, we grow different types of carbon nanotube (CNT) forests directly on AlNbased electroacoustic biosensors and study their functionalization efficiency. CNTs are used to increase the effective surface area of the sensor, pursuing a better sensitivity, without increasing the sensor capacitance. Here we use a general method for CNT bio-functionalization with specific receptors for tar...

Journal: :The Analyst 2009
Chaudhery Mustansar Hussain Chutarat Saridara Somenath Mitra

We demonstrate that the functionalization of carbon nanotubes dramatically alters their sorption characteristics. The effect of covalent functionalization of multiwalled carbon nanotubes (MWNTs) on the gas phase adsorption and desorption of polar and nonpolar organics is presented. Carboxylation and nitration led to the generation of polar functional groups on the nanotube surface. The derivati...

2010
In-Yup Jeon Eun-Kyoung Choi Seo-Yoon Bae Jong-Beom Baek

The feasibility of edge-functionalization of graphite was tested via the model reaction between pyrene and 4-(2,4,6-trimethylphenyloxy)benzamide (TMPBA) in poly(phosphoric acid) (PPA)/phosphorous pentoxide (P(2)O(5)) medium. The functionalization was confirmed by various characterization techniques. On the basis of the model study, the reaction condition could be extended to the edge-functional...

2016
Xiao‐Hua Cai Bing Xie

Received: 20 February 2016 Accepted: 19 March 2016 Published online: 30 June 2016 Printed: 30 June 2016 Direct and selective carbon‐hydrogen bond functionalization has attracted enormous attention because it provides more efficient strategies for preparing valuable functional molecules from easily available substrates. Significant and exciting developments in functionalization of un‐activation ...

2016
Srimanta Manna Andrey P. Antonchick

The synthesis of small rings by functionalization of C(sp(3) )-H bonds remains a great challenge. We report for the first time a copper-catalyzed [1+1+1] cyclotrimerization of acetophenone derivatives under mild reaction conditions. The reaction has a broad scope for the stereoselective synthesis of cyclopropanes by trimerization of acetophenone. The developed transformation is based on an extr...

Journal: :Journal of the American Chemical Society 2009
William J Tenn Brian L Conley Claas H Hövelmann Mårten Ahlquist Robert J Nielsen Daniel H Ess Jonas Oxgaard Steven M Bischof William A Goddard Roy A Periana

We report that SeO2 catalyzes the facile oxy-functionalization of (CO)5Re(I)-Me(delta-) with IO4(-) to generate methanol. Mechanistic studies and DFT calculations reveal that catalysis involves methyl group transfer from Re to the electrophilic Se center followed by oxidation and subsequent reductive functionalization of the resulting CH3Se(VI) species. Furthermore, (CO)3Re(I)(Bpy)-R (R = ethyl...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تحصیلات تکمیلی علوم پایه زنجان - دانشکده شیمی 1391

چکیده در بخش اول این پروژه میکروکره های پلی استایرن بوسیله پلیمرشدن توزیعی مقادیر مختلف استایرن در مخلوط آب و اتانول، از طریق یک فرایند تک مرحله ای تهیه شد. در قسمت دوم از این بخش، برای تهیه میکروکره های هیبریدی با نانوذرات اکسیدآهن در حدود 100-50 نانومتر بوسیله روش دانه گذاری، ابتدا سطح میکروکره های پلی استایرن بوسیله گروه سولفونیک اسید عامل دار شد و سپس بوسیله واکنش مستقیم گروه –so3h سطح پلی...

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