期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
Co-Catalyzed Dehydrogenation Claisen Condensation of Secondary Alcohols with Esters
1
作者 Shuo Gao Wentao Hao +3 位作者 Yuqi Ji Xiulin Li Chunyan Zhang Guoying Zhang 《Chinese Journal of Chemistry》 SCIE CAS 2024年第22期2818-2824,共7页
Comprehensive Summary Catalytic dehydrogenation,with its exceptional atom economy and chemoselectivity,offers a highly desirable yet challenging approach for converting multiple environmentally friendly alcohols into ... Comprehensive Summary Catalytic dehydrogenation,with its exceptional atom economy and chemoselectivity,offers a highly desirable yet challenging approach for converting multiple environmentally friendly alcohols into crucial molecules.Furthermore,the utilization of catalysts based on abundant elements found on Earth for alcohol dehydrogenation to produce acryl ketone holds significant promise as a versatile strategy in synthesizing key building blocks for numerous pharmaceutical applications.The present study describes a practical Co-catalyzed cascade dehydrogenative Claisen condensation of secondary alcohols with esters,facilitating the synthesis of a wide range of 3-hydroxy-prop-2-en-1-ones.We introduce a catalytic system based on novel and scalable indazole NNP-ligands coordinated to cobalt for efficient dehydrogenations of secondary alcohols,and propose a plausible reaction mechanism supported by control experiments and labeling studies.Notably,it allows for the streamlined synthesis of multiple pharmaceuticals in one-pot. 展开更多
关键词 Cobalt Pincer Ligand Dehydrogenation claisen condensation 3-Hydroxy-prop-2-en-1-one Alcohols 3d transition metals Enols Enones
原文传递
A One-pot Approach to Ethyl 1,4,5-Triaryl-lH-pyrazole-3- carboxylates via an Improved Claisen Condensation- Knorr Reaction Sequence 被引量:1
2
作者 Jiaojiao Zhai Chunhui Gu +5 位作者 Jianan Jiang Shunli Zhang Daohua Liao Lei Wang Dunru Zhu Yafei Ji 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2013年第12期1526-1538,共13页
A one-pot approach to ethyl 1,4,5-triaryl-lH-pyrazole-3-carboxylates has been developed in moderate to high yields. The tert-BuOLi-mediated Claisen condensation of 1,2-diarylethanones and ethyl oxalyl chloride efficie... A one-pot approach to ethyl 1,4,5-triaryl-lH-pyrazole-3-carboxylates has been developed in moderate to high yields. The tert-BuOLi-mediated Claisen condensation of 1,2-diarylethanones and ethyl oxalyl chloride efficiently provided the enolized lithium salts of ethyl 2,4-dioxo-3,4-diarylbutanoates, which in situ reacted with arylhydrazine hydrochlorides via a hydrochloric acid-promoted Knorr reaction to produce the exquisite triarylpyrazole-3- carboxylates. The procedure promises a convenient access to this highly crowded framework for drug discovery. 展开更多
关键词 one-pot approach 2 4-dioxo-3 4-diarylbutanoates claisen condensation Knorr reaction triarylpyrazole-3-carboxylates
原文传递
Enhancing the activity and succinyl-CoA specificity of 3-ketoacyl-CoA thiolase Tfu_0875 through rational binding pocket engineering
3
作者 Lixia Liu Shuang Liu +2 位作者 Xiangyang Hu Shenghu Zhou Yu Deng 《Synthetic and Systems Biotechnology》 SCIE CSCD 2024年第3期558-568,共11页
The 3-ketoacyl-CoA thiolase is the rate-limiting enzyme for linear dicarboxylic acids production.However,the promiscuous substrate specificity and suboptimal catalytic performance have restricted its application.Here ... The 3-ketoacyl-CoA thiolase is the rate-limiting enzyme for linear dicarboxylic acids production.However,the promiscuous substrate specificity and suboptimal catalytic performance have restricted its application.Here we present both biochemical and structural analyses of a high-efficiency 3-ketoacyl-CoA thiolase Tfu_0875.Notably,Tfu_0875 displayed heightened activity and substrate specificity for succinyl-CoA,a key precursor in adipic acid production.To enhance its performance,a deep learning approach(DLKcat)was employed to identify effective mutants,and a computational strategy,known as the greedy accumulated strategy for protein engineering(GRAPE),was used to accumulate these effective mutants.Among the mutants,Tfu_0875N249W/L163H/E217L exhibited the highest specific activity(320%of wild-type Tfu_0875),the greatest catalytic efficiency(kcat/KM=1.00 min-1mM-1),the highest succinyl-CoA specificity(KM=0.59 mM,28.1%of Tfu_0875)and dramatically reduced substrate binding energy(-30.25 kcal mol^(-1)v.s.-15.94 kcal mol^(-1)).A structural comparison between Tfu_0875N249W/L163H/E217L and the wild type Tfu_0875 revealed that the increased interaction between the enzyme and succinyl-CoA was the primary reason for the enhanced enzyme activity.This interaction facilitated rapid substrate anchoring and stabilization.Furthermore,a reduced binding pocket volume improved substrate specificity by enhancing the complementarity between the binding pocket and the substrate in stereo conformation.Finally,our rationally designed mutant,Tfu_0875N249W/L163H/E217L,increased the adipic acid titer by 1.35-fold compared to the wild type Tfu_0875 in shake flask.The demonstrated enzymatic methods provide a promising enzyme variant for the adipic acid production.The above effective substrate binding pocket engineering strategy can be beneficial for the production of other industrially competitive biobased chemicals when be applied to other thiolases. 展开更多
关键词 Adipic acid 3-Ketoacyl-CoA thiolase claisen condensation Deep learning GRAPE strategy
原文传递
A modified total synthesis of cystothiazole A
4
作者 YueXia Bai JiLai Bao +1 位作者 Jun Ren ZhongWen Wang 《Science China Chemistry》 SCIE EI CAS 2009年第9期1345-1352,共8页
A modified total synthesis of cystothiazole A is described. In this synthetic strategy, a one-step transformation of acylated oxazolidinone to &#946;-ketoester has been successfully applied, thus making the synthe... A modified total synthesis of cystothiazole A is described. In this synthetic strategy, a one-step transformation of acylated oxazolidinone to &#946;-ketoester has been successfully applied, thus making the synthetic route more efficient. This method may also be potentially applied in synthesis of other related &#946;-substituted-&#946;-methoxyl acrylates (bb-MOAs). 展开更多
关键词 cystothiazole A β -methoxyl acrylate claisen condensation ALDOL total synthesis
原文传递
An Efficient One-pot Synthesis of Aryl-substituted 1-(Thiazol-2-yl)-1H-pyrazole-3-carboxylates via a Hantzsch Synthesis-Knorr Reaction Sequence
5
作者 Chunhui Gu Jiaojiao Zhai +4 位作者 Jianan Jiang Hongwei Liu Lei Wang Dunru Zhu Yafei Ji 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2014年第2期179-190,共12页
The treatment ofα-bromoalkyl aryl ketones and 2-(propan-2-ylidene)hydrazine carbothioamide afforded 4-aryl-2-(2-(propan-2-ylidene)hydrazinyl)thiazoles via a Hantzsch-thiazole synthesis,which reacted with 4-aryl-2,4-d... The treatment ofα-bromoalkyl aryl ketones and 2-(propan-2-ylidene)hydrazine carbothioamide afforded 4-aryl-2-(2-(propan-2-ylidene)hydrazinyl)thiazoles via a Hantzsch-thiazole synthesis,which reacted with 4-aryl-2,4-diketoesters via a sequential Knorr-pyrazole reaction to deliver a variety of aryl-substituted ethyl 1-(thiazol-2-yl)-1Hpyrazole-3-carboxylates in a one-pot fashion with moderate to high yields.The key intermediates 4-aryl-2,4-diketoesters,existing as its enolic lithium salt,were synthesized in situ by a high-yield tert-BuOLi-mediated Claisen condensation of alkylphenones and diethyl oxalate.This class of elegant molecule comprises aryl groups on the two different heterocyclic cores,and the configurations of two representative molecules were determined by single crystal X-ray crystallography. 展开更多
关键词 one-pot synthesis claisen condensation Hantzsch synthesis Knorr reaction 1-(thiazol-2-yl)pyrazole-3-carboxylates
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部