13318-11-1Relevant articles and documents
A convenient preparation of di-p-chlorobenzyl azodicarboxylate (DCAD) for mitsunobu couplings
Taft, Benjamin R.,Swift, Elizabeth C.,Lipshutz, Bruce H.
, p. 332 - 334 (2009)
Gram-scale synthesis of pure, bench-stable solid di-p-chlorobenzyl azodicarboxylate (DCAD) is performed in two steps without resorting to chromatography. This novel reagent effects Mitsunobu couplings with yields comparable to DEAD or DIAD, while addressi
Quaternary Alkyl Ammonium Salt-Catalyzed Transformation of Glycidol to Glycidyl Esters by Transesterification of Methyl Esters
Tanaka, Shinji,Nakashima, Takuya,Maeda, Toshie,Ratanasak, Manussada,Hasegawa, Jun-Ya,Kon, Yoshihiro,Tamura, Masanori,Sato, Kazuhiko
, p. 1097 - 1103 (2018/02/14)
Catalytic transformation of glycidol while maintaining its epoxide moiety intact is challenging because the terminal epoxide that interacts with the hydroxyl group via a hydrogen bond is labile for the ring-opening reaction. We found that a quaternary alkyl ammonium salt catalyzes the selective transformation of glycidol to glycidyl esters by transesterification of methyl esters. The developed method can be applied to the synthesis of multiglycidyl esters, which are valuable epoxy resin monomers. Mechanistic studies revealed the formation of a binding complex of glycidol and quaternary alkyl ammonium salt in a nonpolar solvent and the generation of the alkoxide anion as a catalyst through the ring-opening reaction of the epoxide. Computational studies of the reaction mechanism indicated that the alkoxide anion derived from glycidol tends to abstract the proton of another glycidol rather than work as a nucleophile, initiating the catalytic transesterification. Payne rearrangement of the deprotonated glycidol, which produces a destabilized base that promotes nonselective reactions, is energetically unfavorable due to the double hydrogen bond between the anion and diol. The minimal interaction between the quaternary alkyl ammonium cation and the epoxide moiety inhibited the random ring-opening pathway leading to polymerization.
METHOD FOR PRODUCING GLYCIDYL ESTER
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Paragraph 0032; 0034-0038, (2017/11/09)
PROBLEM TO BE SOLVED: To provide a production method which makes it possible to obtain glycidyl ester with high yields from the ester exchange reaction between ester and glycidol with a convenient catalyst in a mild reaction condition. SOLUTION: Glycidyl ester is produced by the ester exchange reaction between ester and glycidol in the presence of a polystyrene-carrying quaternary ammonium salt. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
Simplification of the Mitsunobu reaction. Di-p-chlorobenzyl azodicarboxylate: A new azodicarboxylate
Lipshutz, Bruce H.,Chung, David W.,Rich, Brian,Corral, Ricardo
, p. 5069 - 5072 (2007/10/03)
(Chemical Equation Presented) Di-p-chlorobenzyl azodicarboxylate (DCAD) is introduced as a novel, stable, solid alternative to DEAD and DIAD for a variety of Mitsunobu couplings. DCAD/Ph3P-mediated reactions in CH 2Cl2 gen
Regioselective opening of an oxirane system with trifluoroacetic anhydride. A general method for the synthesis of 2-monoacyl- and 1,3-symmetrical triacylglycerols
Stamatov, Stephan D.,Stawinski, Jacek
, p. 3659 - 3669 (2007/10/03)
A trifluoroacetic anhydride-catalyzed opening of the oxirane system of glycidyl esters with a simultaneous migration of the acyl group provides a new, efficient entry to either 2-monoacylglycerols (2-MAG) or 1,3-symmetrical triglycerides (1,3-STG) as potential prodrug frameworks.
Highly chemoselective hydrogenation with retention of the epoxide function using a heterogeneous Pd/C - Ethylenediamine catalyst and THF
Sajiki, Hironao,Hattori, Kazuyuki,Hirota, Kosaku
, p. 2200 - 2204 (2007/10/03)
In general, palladium-carbon (Pd/C) catalyzed hydrogenation of epoxides affords the corresponding primary and secondary alcohols as a mixture. It has been found that the catalytic activity of a Pd/C - ethylenediamine complex catalyst [Pd/C(en)] in the hydrogenolysis of epoxide functions is drastically reduced. Herein we describe a mild and chemoselective method for the hydrogenation of olefin, nitro, and azide functions with retention of the epoxide function. The chemoselectivity was accomplished by using a combination of 5% Pd/C(en) and THF as solvent. A significant drop in the chemoselectivity of the hydrogenation is observed with 5% Pd/C(en) in MeOH. These results reinforce the utility of epoxides as important precursors of alcohols in synthetic chemistry.
Novel synthesis and enzymatic resolution of (±)-2,3-epoxy propyl esters
Nair, Ranjeet V.,Patil, Prashant N.,Salunkhe, Manikrao M.
, p. 2559 - 2566 (2007/10/03)
A novel method of synthesizing glycidyl esters (±) -2,3-epoxy propyl esters has been developed involving reaction of epichlorohydrin with sodium salt of carboxylic acids in the presence of 15-crown-5 as catalyst with excellent yields. Enzymatic resolution of these glycidyl esters by lipasePS- C has been achieved with remarkable substrate selectivity.
Incorporation of carbohydrates and peptides into large triazine-based screening libraries using automated parallel synthesis
Gustafson, Gary R.,Baldino, Carmen M.,O'Donnell, Mary-Margaret E.,Sheldon, Adrian,Tarsa, Robert J.,Verni, Christopher J.,Coffen, David L.
, p. 4051 - 4065 (2007/10/03)
A procedure for the sequential, selective derivatization of cyanuric chloride that allows for the incorporation of carbohydrates and peptides has been elucidated. As a result, large combinatorial arrays of individual derivatives, over 40,000 in all, have
Methyleneoxirane-cyclopropanone and related rearrangements in C3H4O cation radicals and neutral molecules. A quest for the oxyallyl intermediate
Turecek, Frantisek,Drinkwater, Donald E.,McLafferty, Fred W.
, p. 5950 - 5958 (2007/10/02)
The formation, relative stabilities, isomerizations, and dissociations of several C3H4O cation radicals and neutral molecules have been investigated by neutralization-reionization mass spectrometry (NRMS) and ab initio calculations (
