Thiol–ene Click Reaction as a General Route to Functional Trialkoxysilanes for Surface Coating Applications
摘要:
Functionalized trialkoxysilanes are widely used to modify the surface properties of materials and devices. It will be shown that the photoinitiated radical-based thiol-ene "click" reaction provides a simple and efficient route to diverse trialkoxysilanes. A total of 15 trialkoxysilanes were synthesized by reacting either alkenes with 3-mercaptopropyltrialkoxysilane or thiols with allyltrialkoxysilanes in the presence of a photoinitiator. The functionalized trialkoxysilanes were obtained in quantitative to near-quantitative yields with high purity. The photochemical reactions can be run neat in standard borosilicate glassware using a low power 15-W blacklight. A wide range of functional groups is tolerated in this approach, and even complex alkenes click with the silane precursors. To demonstrate that these silanes can be used as surface coating agents, several were reacted with iron oxide superparamagnetic nanoparticles and the loadings quantified. The photoinitiated thiol-ene reaction thus offers a facile and efficient method for preparing surface-active functional trialkoxysilanes.
Stereoselective Synthesis of Z Fluoroalkenes through Copper-Catalyzed Hydrodefluorination of <i>gem</i>
-Difluoroalkenes with Water
作者:Jiefeng Hu、Xiaowei Han、Yu Yuan、Zhuangzhi Shi
DOI:10.1002/anie.201708224
日期:2017.10.16
A copper catalytic system was established for the stereoselective hydrodefluorination of gem‐difluoroalkenes through C−F activation to synthesize various Z fluoroalkenes. H2O is used as the hydrogen source for the fluorine acceptor moiety. This mild catalytic system shows good‐functional group compatibility, accepting a range of carbonyls as precursors to the gem‐difluoroalkenes, including aliphatic
The Mechanism of Caseinolytic Protease (ClpP) Inhibition
作者:Malte Gersch、Felix Gut、Vadim S. Korotkov、Johannes Lehmann、Thomas Böttcher、Marion Rusch、Christian Hedberg、Herbert Waldmann、Gerhard Klebe、Stephan A. Sieber
DOI:10.1002/anie.201204690
日期:2013.3.4
Catch me if you can: The ClpPprotease mediates protein homeostasis and can be efficiently inhibited by β‐lactones. A combination of molecular docking, mutagenesis, activity‐based protein profiling, and kinetics studies now reveals the mechanism of ClpPinhibition. A hydrophobic pocket next to the active site allows binding of long aliphatic and aromatic residues. The preferred stereoisomer binds into
A Facile, Catalytic and Environmentally Benign Method for Esterification of Carboxylic Acids and Transesterification of Carboxylic Esters with Nearly Equimolar Amounts of Alcohols
A practical and green chemical process for the esterification of carboxylic acids with alcohols and transesterification of carboxylic esters in good to excellent yields by using K5CoW12O14·3H2O (0.1 mol%) as catalyst is reported. The catalyst exhibited remarkable reusable activity.
This invention relates to a composition, comprising: an unsaturated functionalized monomer of from about 5 to about 30 carbon atoms, which is: (a) polymerized to form a functionalized polymer; (b) copolymerized with a comonomer to form a functionalized copolymer; or (c) reacted with an enophilic reagent to form a polyfunctionalized monomer. The polyfunctionalized monomer may be polymerized to form a polyfunctionalized polymer which may be further reacted with one or more additional reagents. The invention relates to lubricants, functional fluids, fuels, dispersants, detergents and polymeric resins.
Practical and Robust Method for Regio- and Stereoselective Preparation of (<i>E</i>)-Ketene <i>tert</i>-Butyl TMS Acetals and β-Ketoester-derived <i>tert</i>-Butyl (1<i>Z</i>,3<i>E</i>)-1,3-Bis(TMS)dienol Ethers
We developed an efficient, practical, robust method for the regio- and stereoselective preparation of (E)-ketene trimethylsilyl acetals (KSAs) derived from tert-butyl esters 1. The reaction was performed under convenient reaction conditions; LDA−TMSCl, 0−5 °C, and cyclopentyl methyl ether (CPME) solvent. Two kinds of (Z)- and (E)-KSAs derived from α-oxygen and α-nitrogen-substituted tert-butyl esters