Cesium Carbonate Catalyzed Esterification of N-Benzyl-N-Boc-amides under Ambient Conditions
摘要:
We report a general activated amide to ester transformation catalyzed by Cs2CO3. Using this approach, esterification proceeds under relatively mild conditions and without the need for a transition metal catalyst. This method exhibits broad substrate scope and represents a practical alternative to existing esterification strategies. The synthetic utility of this protocol is demonstrated via the facile synthesis of crown ether derivatives and the late-stage modification of a representative natural product and several sugars in reasonable yields.
Unsymmetrical dicarboxylic esters as bleach precursors
申请人:Lever Brothers Company, division of Conopco, Inc.
公开号:US05078907A1
公开(公告)日:1992-01-07
A bleach precursor compound, its peroxygen derivative, and detergent compositions containing these materials are disclosed herein. The bleach precursors structurally comprise a pair of different diesters, one ester containing an electrically-charged functional group. Perhydrolysis of the precursor in the presence of hydrogen peroxide and a basic aqueous media generates a peroxycarboxylic acid.
Production of Terephthalic Acid Di-Esters Using Alcohol-Amine Promoters
申请人:Eastman Chemical Company
公开号:US20150133683A1
公开(公告)日:2015-05-14
The invention is directed to a process for preparing a terephthalic acid di-ester. The process includes contacting terephthalic acid with a C
6
-C
10
alcohol in the presence of an organo-titanium catalyst and an alcohol-amine promoter under conditions effective to form a corresponding terephthalic acid di-ester. The promoter can improve the reaction time by as much as 50%.
Catalytic Depolymerization of Polymers Containing Electrophilic Linkages Using Nucleophilic Reagents
申请人:Hedrick James Lupton
公开号:US20110004014A1
公开(公告)日:2011-01-06
The disclosure relates to methods and materials useful for depolymerizing a polymer. In one embodiment, for example, the disclosure provides a method for depolymerizing a polymer containing electrophilic linkages, wherein the method comprises contacting the polymer with a nucleophilic reagent in the presence of a guanidine-containing compound. The methods and materials of the disclosure find utility, for example, in the field of waste reclamation and recycling.
Catalytic depolymerization of polymers containing electrophilic linkages using nucleophilic reagents
申请人:——
公开号:US20040127720A1
公开(公告)日:2004-07-01
A method is provided for carrying out depolymerization of a polymer containing electrophilic linkages in the presence of a catalyst and a nucleophilic reagent, wherein production of undesirable byproducts resulting from polymer degradation is minimized. The reaction can be carried out at a temperature of 80° C. or less, and generally involves the use of an organic, nonmetallic catalyst, thereby ensuring that the depolymerization product(s) are substantially free of metal contaminants. In an exemplary depolymerization method, the catalyst is a carbene compound such as an N-heterocyclic carbene, or is a precursor to a carbene compound. The method provides an important alternative to current recycling techniques such as those used in the degradation of polyesters, polyamides, and the like.
The present invention relates to an electrochromic polymer compound composed of a hyperbranched polymer having electrochromic characteristics derived from a quaternary pyridinium salt, a terephthalic acid diester or a biphenyl-4,4′-diester structure, and a varnish, a thin film structure and an electrochromic device that are obtained by the polymer compound. The electrochromic material has high response speed, high coloring efficiency, and excellent repetition stability and can be used for a long time, and has excellent solubility in various solvents.