17895-71-5Relevant academic research and scientific papers
Protonic Reorganization and Substrate Structure in Catalysis by Serine Proteases
Elrog, James P.,Hogg, John L.,Quinn, Daniel M.,Venkatasubban, K. S.,Schowen, Richard L.
, p. 3917 - 3922 (1980)
Proton inventories (rate measurements in binary mixtures of protium and deuterium oxides) have been used to estimate the number of protons involved in hydrolytic catalysis by serine proteases with various substrates.Trypsin with the oligopeptide analogue
N-heterocyclic carbene catalyzed enantioselective [3 + 2] dearomatizing annulation of saturated carboxylic esters with n-iminoisoquinolinium ylides
Zhang, Pengfei,Zhou, Yu,Han, Xu,Xu, Jinyi,Liu, Hong
, p. 3879 - 3888 (2018)
The dearomatizing annulation reaction is a significant challenge in organic chemistry. The direct activation of α-carbons of simple saturated esters, as nucleophiles, is an important synthesis strategy. In the present study, we disclose [3 + 2] dearomatizing annulation reactions with direct activating α-carbons of saturated carboxylic esters and N-iminoisoquinolinium ylides, which possess highly enantioselective characteristics, catalyzed by N-heterocyclic carbenes (NHCs). The protocol achieves isoquinoline dearomatization and the construction of tricyclic chiral products under mild conditions with good yield, substrate tolerance, and diastereoselectivity as well as excellent enantioselectivity.
Isothiourea-catalysed transfer hydrogenation of α,β-unsaturated para-nitrophenyl esters
Smith, Andrew D.,Wu, Jiufeng,Young, Claire M.
, (2020/12/21)
A protocol for the isothiourea-catalysed transfer hydrogenation of α,β-unsaturated para-nitrophenyl esters using Hantzsch ester has been developed. Good to excellent yields are observed using α,β-unsaturated aryl esters bearing electron-withdrawing β-subs
Self-supported N-heterocyclic carbenes and their use as organocatalysts
Ma, Shuang,Toy, Patrick H.
, (2016/08/30)
The study of N-heterocyclic carbenes (NHCs) as organocatalysts has proliferated in recent years, and they have been found to be useful in a variety of reactions. In an attempt to further expand their utility and to study their recyclability, we designed and synthesized a series of self-supported NHCs in which the catalytic carbene groups form part of a densely functionalized polymer backbone, and studied them as organocatalysts. Of the self-Supported NHCs examined, a benzimidazole derived polymer with flexible linkers connecting the catalytic groups was found to be the most efficient organocatalyst in a model benzoin condensation reaction, and thus it was used in a variety of such reactions, including some involving catalyst recycling. Furthermore, it was also used to catalyze a set of redox esterification reactions involving conjugated unsaturated aldehydes. In all of these reactions the catalyst afforded good yield of the desired product and its polymeric nature facilitated product purification.
Olefins from biomass feedstocks: Catalytic ester decarbonylation and tandem Heck-type coupling
John, Alex,Hogan, Levi T.,Hillmyer, Marc A.,Tolman, William B.
supporting information, p. 2731 - 2733 (2015/03/05)
With the goal of avoiding the need for anhydride additives, the catalytic decarbonylation of p-nitrophenylesters of aliphatic carboxylic acids to their corresponding olefins, including commodity monomers like styrene and acrylates, has been developed. The reaction is catalyzed by palladium complexes in the absence of added ligands and is promoted by alkali/alkaline-earth metal halides. Combination of catalytic decarbonylation and Heck-type coupling with aryl esters in a single pot process demonstrates the viability of employing a carboxylic acid as a "masked olefin" in synthetic processes. This journal is
Organocatalytic activation of alkylacetic esters as enolate precursors to react with α,β-unsaturated imines
Hao, Lin,Chen, Shaojin,Xu, Jianfeng,Tiwari, Bhoopendra,Fu, Zhenqian,Li, Tong,Lim, Jieyan,Chi, Yonggui Robin
supporting information, p. 4956 - 4959 (2013/10/22)
Asymmetric functionalization of alkylacetic esters and their derivatives is traditionally achieved via preformed enolates with chiral auxiliaries. Catalytic versions of such transformations are attractive but challenging. A direct catalytic activation of simple alkylacetic esters via N-heterocyclic carbene organocatalysts to generate chiral enolate intermediates for highly enantioselective reactions is reported.
Fingerprint lipolytic enzymes with chromogenic p-nitrophenyl esters of structurally diverse carboxylic acids
Qian, Le,Liu, Jia-Yan,Liu, Jia-Ying,Yu, Hui-Lei,Li, Chun-Xiu,Xu, Jian-He
experimental part, p. 22 - 26 (2012/02/06)
A series of structurally diverse chromogenic esters, including a new compound (4-nitrophenyl 2-methylpentanoate), has been synthesized, constituting an array of 17 substrates which could be applied to rapidly fingerprint the activity of lipases or esterases to reveal their substrates specificity and functional characteristics. Combined with genetic technology such as "data mining" and directed evolution, such fingerprints might be a promising platform for discovery of potentially useful enzymes in industrial application. The fingerprint of commercially available Lipase-B from Candida antarctica as a model enzyme was first measured to confirm the reliability of this method. Then three new enzymes mined from genomic libraries were successfully fingerprinted, revealing the functional characteristics of those enzymes. Among them, the enzyme SrfAD was founded with specific substrate preference towards cycloalkyl carboxylic esters and aromatic esters, making it more promising in synthetic utilities than other tested enzymes.
An invesigation of activities and paraoxon sensitivities of hepatic aliesterases in β-naphthoflavone-treated rats
Watson, Angela M.,Chambers, Howard,Chambers, Janice E.
, p. 217 - 226 (2007/10/03)
Aliesterases (carboxylesterases, EC 3.1.1.1) are serine esterases which may protect acetylcholinesterase during organophosphorus insecticide intoxication by providing alternative phosphorylation sites. Levels of hepatic aliesterase activity were investigated after the intraperitoneal administration of β-naphthoflavone (BNF) to female rats using nine 4-nitrophenyl esters as substrates (including straight and branched chain aliphatic and aromatic esters) and 1-naphthyl acetate. In addition, the in vitro sensitivities of aliesterases to inhibition by paraoxon, the active metabolite of the common insecticide parathion, were studied. Hepatic aliesterases from BNF-treated rats displayed lower activities than those from controls with all substrates except 4-nitrophenyl phenylbutyrate and isovalerate. The aliesterases from BNF-treated rats were more sensitive to paraoxon inhibition with 4-nitrophenyl phenylbutyrate, valerate, and butyrate. Esterases hydrolyzing 4-nitrophenyl butyrate, valerate, and branched chain esters were most sensitive to paraoxon inhibition while those hydrolyzing 4-nitrophenyl hexanoate and aromatic esters were least sensitive. The results suggested that BNF-induced changes in hepatic aliesterases could alter responses to organophosphates. Keywords: Aliesterases; β-Naphthoflavone; Paraoxon; Organophosphate
A New and Efficient Esterification Reaction via Mixed Anhydrides by the Promotion of a Catalytic Amount of Lewis Acid
Miyashita, Mitsutomo,Shiina, Isamu,Miyoshi, So,Mukaiyama, Teruaki
, p. 1516 - 1527 (2007/10/02)
In the presence of a catalytic amount of Lewis acid, various carboxylic esters or S-phenyl carbothioates are prepared in excellent yields by the respective reactions of equimolar amounts of silyl carboxylates and alkyl silyl ethers or phenyl silyl sulfides with 4-trifluoromethylbenzoic anhydride.
Nitrogen Participation in the Deacylation of D-Glucosamine and α-Chymotrypsin Derivatives. Explanation of the Stereospecificity of Acyl-α-Chymotrypsin Hydrolysis
Oetvoes, Laszlo,Kraicsovits, Ferenc
, p. 5009 - 5014 (2007/10/02)
The hydrolysis of ethyl 3,4,6-tri-O-acetyl-2-deoxy-2-amino-β-D-glucopyranoside and acylated α-chymotrypsins has been investigated.Both transformations are catalyzed by neighbouring nitrogen atom participation.The stereospecificity of acylated enzyme hydrolysis can be explained by the specific steric hindrance of nitrogen participation.Keywords: selective deacylation, stereospezific ester hydrolysis, acylated derivatives of α-chymotrypsin, 2-amino-2-deoxy-glucose
