期刊文献+
共找到41篇文章
< 1 2 3 >
每页显示 20 50 100
Co/Fe Dual Catalysis for Sequential Hydrosilylation-Isomerization:Access to Trisubstituted(E)-Alkenyl Silanes from Terminal Alkynes
1
作者 Zhihao Guo Guixia Liu Zheng Huang 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第16期1860-1866,共7页
By rational modification of electronic and steric properties of pincer ligands,a Co/Fe dual catalyst system is developed for one-pot sequential Markovnikov alkyne hydrosilylation and stereoselective alkene isomerizati... By rational modification of electronic and steric properties of pincer ligands,a Co/Fe dual catalyst system is developed for one-pot sequential Markovnikov alkyne hydrosilylation and stereoselective alkene isomerization.The protocol provides an atom-economical and efficient approach to trisubstituted(E)-alkenyl silanes from widely accessible terminal alkynes with high regio-and stereoselectivities under mild conditions.The utility of this reaction was demonstrated by gram-scale synthesis and derivatization of bioactive molecules.The radical clock and trapping experiments indicated that radical pathway might be operative in the alkene isomerization step. 展开更多
关键词 Cobalt dual catalysis HYDROSILYLATION Iron ISOMERIZATION Trisubstituted alkenyl silanes
原文传递
Dynamic kinetic stereodivergent transformations of propargylic ammonium salts via dual nickel and copper catalysis
2
作者 Ruilong Geng Lingzi Peng Chang Guo 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第8期265-269,共5页
The dynamic kinetic asymmetric transformation of racemic propargylic ammonium salts with prochiral aldimine esters through a stereodivergent propargylation is catalyzed by dual nickel and copper catalysis.Thus,a diver... The dynamic kinetic asymmetric transformation of racemic propargylic ammonium salts with prochiral aldimine esters through a stereodivergent propargylation is catalyzed by dual nickel and copper catalysis.Thus,a diverse range of optically activeα-quaternary amino esters were produced via C-N bond cleavage with high reaction efficiency and stereoselectivity(up to>99%ee).By selection of the appropriate pair-wise combination of catalyst configurational isomers,all four possible stereoisomers of the corresponding propargylation products are obtained in high yields with excellent regio-,diastereo-,and enantioselectiv-ities. 展开更多
关键词 Stereodivergent propargylation dual catalysis C-N bond cleavage Azaomethine ylides Internal propargylic ammonium salts Excellent stereoselectivity
原文传递
Recent advances in annulations enabled by nucleophilic Lewis base/metal dual catalysis
3
作者 Qian Wang Yinggao Meng +1 位作者 Lulu Wu Er-Qing Li 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第10期12-26,共15页
Metal/nucleophilic Lewis base dual catalysis has been recognized as a reliable and promising strategy for finishing ideal organic synthesis over the past decades.The new strategy can usually achieve some chemical reac... Metal/nucleophilic Lewis base dual catalysis has been recognized as a reliable and promising strategy for finishing ideal organic synthesis over the past decades.The new strategy can usually achieve some chemical reactions that cannot be realized by the traditionally mono-catalytic system,dramatically expanding the synthetic utility of chemical transformations by leveraging additional activation modes.Thus considerable progress has been made in the synthesis of a wide range of heterocyclic and biologically active compounds by using the combination of diversely metal/nucleophilic Lewis base dual catalysts,including metal/phosphine,metal/N-heterocyclic carbene(NHC)and metal/tertiary amine dual catalysis systems.In this review,we describe a comprehensive and updated advance of metal/nucleophilic Lewis base dual catalytic annualtion reactions,meanwhile,the related mechanism and the application of these annulation strategies in natural product total synthesis will be highlighted in detail. 展开更多
关键词 Lewis base Metal catalysis Annualtion dual catalysis Synthetic methods
原文传递
双介质阻挡放电等离子体协同催化降解恶臭废气技术研究 被引量:1
4
作者 金成刚 李建鹏 +2 位作者 宋磊 刘京湘 刘东旭 《节能技术》 CAS 2023年第1期89-92,共4页
恶臭废气破坏环境的同时对周边居民生活造成很大困扰,而且还比较难以完全消除。本文提出了利用双介质阻挡放电(DBD)等离子体协同催化系统去除恶臭废气。系统采用排管式DBD模块,结合分段式催化模块。对垃圾处置中心外排臭气进行中试研究... 恶臭废气破坏环境的同时对周边居民生活造成很大困扰,而且还比较难以完全消除。本文提出了利用双介质阻挡放电(DBD)等离子体协同催化系统去除恶臭废气。系统采用排管式DBD模块,结合分段式催化模块。对垃圾处置中心外排臭气进行中试研究,并给出了将垃圾恶臭废气的综合治理方案。结果显示:单一双DBD等离子体输入功率在0.5~2 kW区间内,输入功率与臭气中各污染物的降解率呈现正相关,其中臭味浓度的降解率最高约为75%。采用双DBD等离子体协同催化恶臭废气的方式对O 3的平均催化分解率可达94%,臭味浓度的降解率由75%提高到95%。这对恶臭废气处理技术在电力工业等许多行业中应用具有重要的意义和价值。 展开更多
关键词 双介质阻挡 等离子 体协同催化 废气降解 工业应用
下载PDF
成型方法对Ni-CaO双功能材料CO_(2)吸附与催化转化一体化性能的影响 被引量:1
5
作者 余钧 郭亚飞 +3 位作者 王国栋 黄浦 赵传文 王涛 《精细化工》 EI CAS CSCD 北大核心 2023年第1期130-138,共9页
CO_(2)捕集-转化一体化工艺是实现碳中和的关键负排放技术,而兼具吸附和催化活性的双功能材料(DFMs)构筑是关键。采用挤压法、挤压滚圆法和压片法构筑了柱状、球形和片状的Ni-CaO DFMs,探究了成型方法对Ni-CaO DFMs的结构和CO_(2)吸附-... CO_(2)捕集-转化一体化工艺是实现碳中和的关键负排放技术,而兼具吸附和催化活性的双功能材料(DFMs)构筑是关键。采用挤压法、挤压滚圆法和压片法构筑了柱状、球形和片状的Ni-CaO DFMs,探究了成型方法对Ni-CaO DFMs的结构和CO_(2)吸附-催化一体化性能的影响。研究发现,成型方法会破坏Ni-CaO DFMs的孔隙结构,对其CO_(2)体相扩散和吸附产生不利影响。在首次循环中,Ni-CaO粉体在650℃和体积分数为10%CO_(2)气氛下的吸附容量高达11.77 mmol CO_(2)/g,在体积分数为5%H2气氛下原位逆水煤气变换的CO产量达4.81 mmol CO/g;而成型Ni-CaO DFMs的CO_(2)吸附容量降至9.67~10.33 mmol CO_(2)/g,CO_(2)催化转化率得到明显提升。成型方法有利于提升Ni-CaO DFMs的CO_(2)吸附循环稳定性。在12次循环后,未成型Ni-CaO粉体的CO_(2)吸附容量循环衰减率达31.35%,而成型Ni-CaO DFMs的循环衰减率为9.36%~24.23%。 展开更多
关键词 Ni-CaO DFMs 成型方法 CO_(2)吸附-催化一体化 逆水煤气变换 催化技术
下载PDF
A review of enantioselective dual transition metal/photoredox catalysis 被引量:4
6
作者 Hong-Hao Zhang Hui Chen +1 位作者 Chengjian Zhu Shouyun Yu 《Science China Chemistry》 SCIE EI CAS CSCD 2020年第5期637-647,共11页
Transition metal catalysis is one of the most important tools to construct carbon-carbon and carbon-heteroatom bonds in modern organic synthesis. Visible-light photoredox catalysis has recently drawn considerable atte... Transition metal catalysis is one of the most important tools to construct carbon-carbon and carbon-heteroatom bonds in modern organic synthesis. Visible-light photoredox catalysis has recently drawn considerable attention of the scientific community owing to its unique activation modes and significance for the green synthesis. The merger of photoredox catalysis with transition metal catalysts, termed metallaphotoredox catalysis, has become a popular strategy for expanding the synthetic utility of visiblelight photocatalysis. This strategy has led to the discovery of novel asymmetric transformations, which are unfeasible or not easily accessible by a single catalytic system. This contemporary area of organic chemistry holds promise for the development of economical and environmentally friendly methods for the asymmetric synthesis of chiral compounds. In this review, the advances in the enantioselective metallaphotoredox catalysis(EMPC) are summarized. 展开更多
关键词 transition metal catalysis photoredox catalysis dual catalysis asymmetric catalysis
原文传递
Photoredox/Ti dual-catalyzed dehydroxylative ring-opening Giese reaction of cyclobutanone oximes
7
作者 Huaigui Li Yan Li +3 位作者 Weidong Yuan Anling Qu Kang Chen Yingguang Zhu 《Green Synthesis and Catalysis》 2024年第3期159-164,共6页
A dehydroxylative ring-opening Giese reaction of cyclobutanone oximes enabled by photoredox/Ti dual catalysis has been reported in this work.This protocol avoids the prefunctionalization of oximes and the use of stoic... A dehydroxylative ring-opening Giese reaction of cyclobutanone oximes enabled by photoredox/Ti dual catalysis has been reported in this work.This protocol avoids the prefunctionalization of oximes and the use of stoichiometric triarylphosphine reagents.It also features mild conditions,broad substrate scope and good functional group tolerance.The gram-scale reaction,product derivatization,late-stage functionalization of complex pharmaceutical and natural product derivatives,and oligopeptide modification exhibit the potential application of this methodology in synthetic chemistry. 展开更多
关键词 Photoredox/Ti dual catalysis Dehydroxylative ring-opening Giese reaction Cyclobutanone oximes γ-Cyanoalkyl radical Distally cyano-substituted amides
原文传递
双功能CuX_(2)参与的芳基-7-氮杂吲哚邻位C-H键的卤化反应
8
作者 周鲜颖 张媛媛 刘珊珊 《广州化学》 CAS 2023年第4期57-60,共4页
开发了一种双功能铜参与催化芳基-7-氮杂吲哚的芳基卤化反应,该方法以N-苯基-7-氮杂吲哚类化合物为底物,CuX_(2)既为卤素源,又可以作为C-H键活化试剂,在无外加催化剂下,通过7-氮杂吲哚的导向作用选择性地发生芳环的亲电卤代反应。经过... 开发了一种双功能铜参与催化芳基-7-氮杂吲哚的芳基卤化反应,该方法以N-苯基-7-氮杂吲哚类化合物为底物,CuX_(2)既为卤素源,又可以作为C-H键活化试剂,在无外加催化剂下,通过7-氮杂吲哚的导向作用选择性地发生芳环的亲电卤代反应。经过一系列条件筛选之后得到最佳反应条件为:CuCl_(2)(0.65eq)为催化剂,DMAP(0.25 eq)为配体,苯甲酸(1.2 eq)为添加剂,氯苯为溶剂,于120℃下反应24小时,产率最高达到95%。除7-氮杂吲哚导向基团外,还成功兼容了吡啶、喹啉等导向基团,该反应可应用于较多的底物范围。 展开更多
关键词 双功能 铜催化 7-氮杂吲哚 卤化 C-H键活化 自催化剂
下载PDF
Stereodivergent synthesis of C-glycosamino acids via Pd/Cu dual catalysis
9
作者 Xiaoxiao Yan Feng Feng +5 位作者 Lin Zhou Linrong Chen Shouchu Tang Jian Liu Feng Cai Xiaolei Wang 《Science China Chemistry》 SCIE EI CAS CSCD 2021年第4期552-557,共6页
Herein,we reported the stereodivergent synthesis of C-glycosamino acids via Pd/Cu dual catalysis and found a suitable system to resolve many challenges,such as the tolerance towards the density of functional groups,th... Herein,we reported the stereodivergent synthesis of C-glycosamino acids via Pd/Cu dual catalysis and found a suitable system to resolve many challenges,such as the tolerance towards the density of functional groups,the variability of the anomeric position,the compatibility of appropriate catalyst combinations,the regioselectivity of nucleophiles,and the match/mismatch problems between chiral substrates and chiral ligand-metal complexes.The method enables the efficient preparation of a series of unnatural C-glycosamino acid skeletons bearing two contiguous stereogenic centers in good yields with excellent diastereoselectivity.From this crucial precursor,various C-glycosamino acid derivatives have been achieved diversely.The readily prepared C-glycosamino acid hybrids will meet the growing demands for the development of new molecular entities for discovering new drugs and materials.This stereodivergent synthesis of C-glycosamino acids will further accelerate the study of their structural features,mode of action,and potential biological applications in the near future. 展开更多
关键词 C-glycosamino acid GLYCOMIMETICS PEPTIDOMIMETICS stereodivergent dual catalysis
原文传递
Dual Palladium/Scandium Catalysis toward Rotationally Hindered C3-Naphthylated Indoles from β-Alkynyl Ketones and o-Alkynyl Anilines
10
作者 Dan Wang Shi-Chao Wang +2 位作者 Wen-Juan Hao Shu-Jiang Tu Bo Jiang 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2021年第1期106-114,共9页
A new dual plldium/scandium catalysis starting fromβ-alkynyl ketones and o alkynyl anilines is reported for the first time,leading to the atom-economic synthesis of rotationally hindered C3-naphthylated indoles in mo... A new dual plldium/scandium catalysis starting fromβ-alkynyl ketones and o alkynyl anilines is reported for the first time,leading to the atom-economic synthesis of rotationally hindered C3-naphthylated indoles in moderate to good yields and high regioselectivi-ty.This method can tolerate normal air conditions,and features the use of palladium/scandium cooperative catalysts without any ligand,facile double annulation involving various internal alkynes,and good functional group tolerance. 展开更多
关键词 dual metallic catalysis Regioselectivity BENZANNULATION Arylated indoles Internal alkynes
原文传递
New process of low-temperature methanol synthesis from CO/CO_2/H_2 based on dual-catalysis
11
作者 曾健青 TSUBAKINoritatsu FUJIMOTOKaoru 《Science China Chemistry》 SCIE EI CAS 2002年第1期106-112,共7页
A new process of low-temperature methanol synthesis from CO/CO2/H2 based on dual-catalysis has been developed. Some alcohols, especially 2-alcohol, were found to have high catalytic promoting effect on the synthesis o... A new process of low-temperature methanol synthesis from CO/CO2/H2 based on dual-catalysis has been developed. Some alcohols, especially 2-alcohol, were found to have high catalytic promoting effect on the synthesis of methanol from CO hydrogenation. At 443 K and 5 MPa, the synthesis of methanol could process high effectively, resulting from the synergic catalysis of Cu/ZnO solid catalyst and 2-alcohol solvent catalyst. The primary results showed that when 2-butanol was used as reaction solvent, the one-pass average yield and the selectivity of methanol, in 40 h continuous reaction at temperature as low as 443 K and 5 MPa, were high up to 46.51% and 98.94% respectively. The catalytic activity was stable and the reaction temperature was 80 K or so lower than that in current industry synthesis process. This new process hopefully will become a practical method for methanol synthesis at low temperature. 展开更多
关键词 dual-catalysis METHANOL LOW-TEMPERATURE SYNTHESIS new process.
原文传递
合成气制混合醇双功能催化研究进展 被引量:39
12
作者 肖康 鲍正洪 +5 位作者 齐行振 王新星 钟良枢 房克功 林明桂 孙予罕 《催化学报》 SCIE EI CAS CSCD 北大核心 2013年第1期116-129,共14页
混合醇合成要求催化剂具备至少两类活性中心, 一类用于解离吸附CO以生成烷基链, 另一类用于非解离吸附CO以使烷基链含氧化生成醇. 两类中心通过协同作用共同构成混合醇合成所需的双活性中心. 简要综述了近年来合成气制混合醇过程中涉及... 混合醇合成要求催化剂具备至少两类活性中心, 一类用于解离吸附CO以生成烷基链, 另一类用于非解离吸附CO以使烷基链含氧化生成醇. 两类中心通过协同作用共同构成混合醇合成所需的双活性中心. 简要综述了近年来合成气制混合醇过程中涉及的双功能催化研究进展, 并以几类典型的催化剂体系为例, 从双活性中心的构筑、典型的双活性中心结构、反应过程中双活中心结构的演变等方面进行了阐述. 混合醇催化剂的研发应从纳米尺度上对催化剂进行设计, 使催化剂表面具有足够多的双活性中心, 并设法稳定催化剂的双活性中心结构. 展开更多
关键词 混合醇 一氧化碳加氢 合成气 双功能催化 双活性中心
下载PDF
双金属催化剂Bi-Mo/TiO_2气相催化氧化2-甲基吡啶合成2-吡啶甲醛 被引量:2
13
作者 张玲玲 俞杰 +2 位作者 王晓钟 张世界 戴立言 《高校化学工程学报》 EI CAS CSCD 北大核心 2016年第5期1082-1087,共6页
制备了气相催化氧化2-甲基吡啶合成2-吡啶甲醛的双金属Bi-Mo/TiO_2催化剂,采用XRD、H_2-TPR、SEM和XPS对催化剂进行了表征,并考察了催化剂组成、反应温度、原料流率等因素的影响。实验研究结果表明,Bi-Mo/TiO_2对2-甲基吡啶有比较高的... 制备了气相催化氧化2-甲基吡啶合成2-吡啶甲醛的双金属Bi-Mo/TiO_2催化剂,采用XRD、H_2-TPR、SEM和XPS对催化剂进行了表征,并考察了催化剂组成、反应温度、原料流率等因素的影响。实验研究结果表明,Bi-Mo/TiO_2对2-甲基吡啶有比较高的催化活性是基于Bi_2Mo_3O_(12)和MoO_3的协同催化作用,Bi2Mo_3O_(12)和MoO_3的较佳摩尔比率为1:1,催化剂的较佳负载量为15%(wt),低反应温度和高原料流率可以提高对2-吡啶甲醛的选择性。较佳反应条件下(反应温度290℃,10%(wt)2-甲基吡啶水溶液的流率为0.5 m L×min-1,氧气的流率为0.1 L×min^(-1),空速12600 h^(-1)),2-甲基吡啶的转化率为70.9%,2-吡啶甲醛的选择性为83.1%。 展开更多
关键词 双金属催化剂 2-甲基吡啶 2-吡啶甲醛 选择性 协同催化
下载PDF
相转移催化合成2-甲基-4’-硝基二苯醚的研究
14
作者 罗志臣 丁元生 《吉林化工学院学报》 CAS 2003年第4期69-70,共2页
以PEG600为催化剂用相转移催化法合成了标题化合物.实验结果表明,该工艺反应平稳,产品 收率高.
关键词 相转移催化 有机合成 2-甲基-4’-硝基二苯醚 催化剂
下载PDF
双酶偶联生物合成L-酪氨酸 被引量:3
15
作者 冯莹莹 刘均忠 +2 位作者 张宏娟 刘茜 焦庆才 《精细化工》 EI CAS CSCD 北大核心 2014年第5期570-574,606,共6页
多酶偶联催化是酶法制备手性药物中间体的重要方法之一。该文采用双酶偶联体系,利用天冬氨酸转氨酶全细胞催化L-天冬氨酸转氨至苯丙酮酸,生成L-苯丙氨酸,同时得到中间产物丙酮酸;反应体系中的酪氨酸酚裂解酶全细胞催化丙酮酸、苯酚和氨... 多酶偶联催化是酶法制备手性药物中间体的重要方法之一。该文采用双酶偶联体系,利用天冬氨酸转氨酶全细胞催化L-天冬氨酸转氨至苯丙酮酸,生成L-苯丙氨酸,同时得到中间产物丙酮酸;反应体系中的酪氨酸酚裂解酶全细胞催化丙酮酸、苯酚和氨酶法合成L-酪氨酸。经考察确定了双酶偶联反应的最佳条件为:温度40℃,pH=8.5,底物苯丙酮酸质量浓度为25 g/L,苯丙酮酸与L-天冬氨酸摩尔比1∶1.2,天冬氨酸转氨酶与酪氨酸酚裂解酶细胞质量比1∶1,4 mmol/L PLP,0.1 g/L吐温80。30 g/L的氯化铵对双酶偶联反应有促进作用。双菌双酶偶联生物法合成L-酪氨酸,充分利用了反应副产物丙酮酸得到附加值较高的产品,对资源合理利用及绿色合成工艺具有参考意义。 展开更多
关键词 双酶偶联 天冬氨酸转氨酶 酪氨酸酚裂解酶 L-酪氨酸 生物工程
下载PDF
双酶级联生物合成D-赖氨酸 被引量:2
16
作者 陆阳 吴四平 +3 位作者 张宏娟 刘茜 焦庆才 刘均忠 《精细化工》 EI CAS CSCD 北大核心 2015年第8期873-877,890,共6页
建立了氨基酸消旋酶和赖氨酸脱羧酶双酶级联高效生产D-赖氨酸的方法。利用氨基酸消旋酶全细胞催化消旋L-赖氨酸得到DL-赖氨酸,去除氨基酸消旋酶后再加入赖氨酸脱羧酶,将消旋产物中的L-构型脱羧生成1,5-戊二胺和CO2,剩下D-赖氨酸;最终,... 建立了氨基酸消旋酶和赖氨酸脱羧酶双酶级联高效生产D-赖氨酸的方法。利用氨基酸消旋酶全细胞催化消旋L-赖氨酸得到DL-赖氨酸,去除氨基酸消旋酶后再加入赖氨酸脱羧酶,将消旋产物中的L-构型脱羧生成1,5-戊二胺和CO2,剩下D-赖氨酸;最终,通过阳离子交换树脂吸附洗脱得到D-赖氨酸。经考察双酶级联催化的最佳条件为:反应温度40℃,0.2 mol/L磷酸钾缓冲溶液(p H=5.8),底物L-赖氨酸质量浓度为50 g/L,氨基酸消旋酶全细胞和赖氨酸脱羧酶全细胞质量浓度均为10 g/L,4 mmol/L磷酸吡哆醛,0.1 g/L Triton X-100,反应时间12 h,其中消旋反应2 h和脱羧反应10 h,最终D-赖氨酸收率达42%,对映体过量值(e.e.值)=98%。 展开更多
关键词 双酶级联催化 氨基酸消旋酶 赖氨酸脱羧酶 D-赖氨酸 生物工程
下载PDF
Ag/MgO串联协同催化降解偶氮染料 被引量:4
17
作者 祝晓辉 郭紫薇 +2 位作者 刘向东 李仁宏 韦童 《无机化学学报》 SCIE CAS CSCD 北大核心 2021年第3期482-490,共9页
以纳米氧化镁为载体,采用浸渍法制备一系列过渡金属负载型催化剂。测试其对染料的降解性能后筛选出了效果最优的催化剂Ag/MgO,并采用X射线衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、扩展X射线吸收精细结构谱(EXAFS)以及X... 以纳米氧化镁为载体,采用浸渍法制备一系列过渡金属负载型催化剂。测试其对染料的降解性能后筛选出了效果最优的催化剂Ag/MgO,并采用X射线衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、扩展X射线吸收精细结构谱(EXAFS)以及X射线吸收近边结构(XANES)等表征方法对该催化材料的结构特征、微观形貌进行分析。通过表征分析发现Ag是以纳米簇的形式均匀地分散在MgO表面,Ag和Mg之间形成了双金属位点,且催化剂中Ag的电子密度较高,从而具有较高的催化活性。在甲醛溶液中,在室温、无需光热等条件下即可高效降解偶氮染料AR1。该反应体系中影响降解效果的因素主要是温度和甲醛浓度,温度升高,降解效率增大,但甲醛浓度有最优值(1 mol·L^(-1))。通过自由基捕获实验测得反应中有2种自由基在发挥作用,即具有还原性的氢自由基和具有氧化性的超氧自由基,它们的协同作用可以将染料分子中的显色基团(—N=N—)轻易地破坏,这种"还原-氧化"的协同作用机制提高了反应效率。此外,醛类也是常见污染物之一,将其作为助剂的同时达到了"以污治污"的效果。 展开更多
关键词 银/氧化镁 纳米催化 偶氮染料降解 活性氧物种 以污治污
下载PDF
Stereodivergent Pd/Cu Catalysis for Asymmetric Desymmetric Alkylation of Allylic Geminal Dicarboxylates 被引量:2
18
作者 Xiaohong Huo Ling Zhao +7 位作者 Yicong Luo Yue Wu Yuwen Sun Guanlin Li Tatiana Gridneva Jiacheng Zhang Yong Ye Wanbin Zhang 《CCS Chemistry》 CAS 2022年第5期1720-1731,共12页
AstereodivergentPd/Cucatalyst systemforasymmetric desymmetric alkylation of allylic geminal dicarboxylates has been developed,which was successfully applied to the asymmetric synthesis of β-hydroxycarbonylmotifs bear... AstereodivergentPd/Cucatalyst systemforasymmetric desymmetric alkylation of allylic geminal dicarboxylates has been developed,which was successfully applied to the asymmetric synthesis of β-hydroxycarbonylmotifs bearing a versatile carbon-carbon double bond in an enantio-and diastereodivergent manner.A wide scope of substrates including challenging alkylsubstituted,2-substituted,and3,3′-disubstitutedallylic species are compatible with this catalytic system,delivering the substituted products in high to excellent yieldsandwith excellent diastereo-(upto>20:1 dr)and enantioselectivities(up to>99%ee).Furthermore,the mechanism of this dual Pd/Cu catalytic system including:(1)the desymmetrization process ofgeminal dicarboxylates;(2)the origin of regioselectivity(branched or linear);(3)the enantio-and diastereoselectivity observed by changing the combinations of two chiral metal catalysts,have been carefully investigated by theoretical calculations. 展开更多
关键词 stereodivergent synthesis bimetallic catalysis DESYMMETRIZATION Pd/Cu dual catalysis asymmetric allylic substitution
原文传递
Brφnsted-Lewis双酸性离子液体的合成及其催化松香二聚反应
19
作者 王金龙 尤兴林 方云 《精细化工》 EI CAS CSCD 北大核心 2014年第3期342-346,共5页
以盐酸为B酸供体将N-甲基咪唑(mim)质子化得到Brφnsted酸性离子液体mim·HCl,继续与Lewis酸供体FeCl3反应合成了一族Brφnsted-Lewis双酸性离子液体氯化-1-氢-3-甲基咪唑氯铁酸盐(1-x)[mim·HCl]x[FeCl3],x为Lewis酸所占的摩... 以盐酸为B酸供体将N-甲基咪唑(mim)质子化得到Brφnsted酸性离子液体mim·HCl,继续与Lewis酸供体FeCl3反应合成了一族Brφnsted-Lewis双酸性离子液体氯化-1-氢-3-甲基咪唑氯铁酸盐(1-x)[mim·HCl]x[FeCl3],x为Lewis酸所占的摩尔分数。分别用吡啶和乙腈探针红外光谱表征和比较了其酸性,并将其应用于催化松香的二聚反应。所合成的一族双酸性离子液体中,(1-x)[mim·HCl]x[FeCl3](x=0.64)催化松香二聚反应时,二聚产物的软化点比空白样品提高了15℃;其催化活性在重复利用5次后才开始下降。 展开更多
关键词 双酸性离子液体 催化剂 松香 二聚反应 二聚松香酸 催化与分离提纯技术
下载PDF
多孔碳负载Cu2O/Cu双相催化剂的制备及应用 被引量:1
20
作者 宋官龙 张瑞凯 +3 位作者 黄子健 苗强 李其明 李芳 《精细化工》 EI CAS CSCD 北大核心 2018年第6期982-986,共5页
以硝酸铜和均苯三甲酸为原料,采用溶剂热合成法制备了金属有机框架材料(Cu-BTC),将其在氮气和空气气氛下焙烧制备了多孔碳负载的Cu2O/Cu催化剂Cu-BTC-1和Cu-BTC-2,并考察了其在对硝基苯酚催化还原中的催化性能。对Cu-BTC-1和Cu-BTC-2... 以硝酸铜和均苯三甲酸为原料,采用溶剂热合成法制备了金属有机框架材料(Cu-BTC),将其在氮气和空气气氛下焙烧制备了多孔碳负载的Cu2O/Cu催化剂Cu-BTC-1和Cu-BTC-2,并考察了其在对硝基苯酚催化还原中的催化性能。对Cu-BTC-1和Cu-BTC-2进行了XRD,SEM,TEM和BET表征。XRD表征结果表明:在氮气气氛中焙烧Cu-BTC可得到多孔碳负载的Cu2O/Cu双相纳米晶材料。SEM和TEM结果表明:相对于Cu-BTC-2催化剂,Cu-BTC-1双相粒子粒径较小,介于10-30 nm之间,比表面积较高,达200 m^2/g。对硝基苯酚催化还原实验结果表明:与Cu-BTC-2(表观速率系数kapp=0.0067s^–1)相比,Cu-BTC-1在对硝基苯酚的还原中具有更高的催化活性(kapp=0.0108 s^-1)。 展开更多
关键词 水热合成 焙烧 双相催化剂 催化 对硝基苯酚
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部