期刊文献+
共找到185篇文章
< 1 2 10 >
每页显示 20 50 100
(Z)-a-Selanyl Alkenyl Grignard Reagents as Convenient Precursors for Stereoselective Synthesis of Trisubstituted Alkenes
1
作者 Ming Zhong CAI Chun Yun PENG Jia Di HUANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2002年第12期1164-1167,共4页
Z)-a-Selanyl alkenyl Grignard reagents 2 were prepared conveniently by treatment of a-bromovinylselenides 1 with magnesium filings in THF. Intermediates 2 were reacted with alkyl iodides in the presence of CuI or Pd(... Z)-a-Selanyl alkenyl Grignard reagents 2 were prepared conveniently by treatment of a-bromovinylselenides 1 with magnesium filings in THF. Intermediates 2 were reacted with alkyl iodides in the presence of CuI or Pd(PPh3)4 to afford (Z)-1,2-disubstituted vinylselenides 3, which were cross-coupled with Grignard reagents in the presence of (PPh3)2NiCl2 to give trisubstituted alkenes 4 stereoselectively in good yields. 展开更多
关键词 a-Bromovinylselenides (Z)-a-selanyl alkenyl Grignard reagents stereoselective synthesis trisubstituted alkene.
下载PDF
Tandem Lewis acid catalysis for the conversion of alkenes to 1,2‐diols in the confined space of bifunctional TiSn‐Beta zeolite 被引量:4
2
作者 Qifeng Lei Chang Wang +4 位作者 Weili Dai Guangjun Wu Naijia Guan Michael Hunger Landong Li 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第7期1176-1184,共9页
The generation of multifunctional isolated active sites in zeolite supports is an attractive method for integrating multistep sequential reactions into a single‐pass tandem catalytic reaction.In this study,bifunction... The generation of multifunctional isolated active sites in zeolite supports is an attractive method for integrating multistep sequential reactions into a single‐pass tandem catalytic reaction.In this study,bifunctional TiSn‐Beta zeolite was prepared by a simple and scalable post‐synthesis approach,and it was utilized as an efficient heterogeneous catalyst for the tandem conversion of alkenes to 1,2‐diols.The isolated Ti and Sn Lewis acid sites within the TiSn‐Beta zeolite can efficiently integrate alkene epoxidation and epoxide hydration in tandem in a zeolite microreactor to achieve one‐step conversion of alkenes to 1,2‐diols with a high selectivity of>90%.Zeolite confinement effects result in high tandem rates of alkene epoxidation and epoxide hydration as well as high selectivity toward the desired product.Further,the novel method demonstrated herein can be employed to other tandem catalytic reactions for sustainable chemical production. 展开更多
关键词 Tandem catalysis Confinement effect ZEOLITE alkene epoxidation Epoxide hydration
下载PDF
Functional Polyethylene Glycol with Carboxyl-supported Platinum as an Efficient Catalysis System for the Hydrosilylation of Alkenes 被引量:1
3
作者 白赢 彭家建 +3 位作者 杨虎 厉嘉云 来国桥 李小年 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第2期246-253,共8页
A series of carboxylated long chain polyethylene glycols(abbreviated as PEGCOOH) has been synthesized and used to support chloroplatinic acid.These supported catalysts were then tested for their efficiency in the hydr... A series of carboxylated long chain polyethylene glycols(abbreviated as PEGCOOH) has been synthesized and used to support chloroplatinic acid.These supported catalysts were then tested for their efficiency in the hydrosilylation of alkenes.The factors affecting their catalytic properties,e.g.relative molecular mass of polyethylene glycol,reaction temperature,platinum content,and type of alkenes,have been studied.It was found that the activity of the platinum catalyst decreased with increasing length of the polyethylene glycol chain,and increased with reaction temperature.Moreover,these catalysts could be reused several times without a noticeable decrease in activity or selectivity.The reaction pathway leading to excellent selectivity for the β-adduct of hydrosilylation of alkenes with triethoxysilane catalyzed by this catalysis system was discussed. 展开更多
关键词 polyethylene glycol modification PLATINUM HYDROSILYLATION alkene
下载PDF
Biomimetic Epxidation of Alkenes by Phenyliodonium Diacetate [PhI(OAc)_2] in the Presence of Mn(Ⅲ) Complex of meso-Tetrakis(4-methoxyphenylporphyrin) Acetate Mn[(T4-OCH_3P)P]OAc 被引量:1
4
作者 KARIMIPOUR Gholamreza KOWKABI Saeed 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2011年第4期592-594,共3页
We have reported that phenyliodonium diacetate[PhI(OAc)2] can serve as an eco-friendly mild oxidant for the epoxidation of alkenes in the presence of Mn(III) complex of meso-tetrakis(4-methoxyphenylporphyrin) ac... We have reported that phenyliodonium diacetate[PhI(OAc)2] can serve as an eco-friendly mild oxidant for the epoxidation of alkenes in the presence of Mn(III) complex of meso-tetrakis(4-methoxyphenylporphyrin) acetate Mn[(T4-OCH3P)P]OAc and imidazole in CH2Cl2.The amounts of the products(%) and selectivities are very dependent upon the electronic and steric properties of the starting alkenes.To evaluate the validity of this catalytic system for C "H activation,cyclohexane and ethylbenzene were oxidized under the epoxidation conditions. 展开更多
关键词 Porphyrin alkene EPOXIDATION Phenyliodonium diacetate
下载PDF
Hydrogenation of Alkenes with NaBH4, CH3CO2H, Pd/C in the Presence of O- and N-Benzyl Functions 被引量:3
5
作者 Nuha Al Soom Thies Thiemann 《International Journal of Organic Chemistry》 CAS 2016年第1期1-11,共11页
NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemosele... NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemoselectively, making it possible to hydrogenate alkenes under Pd/C catalysis with hydrogen created in situ without O- or N-debenzylation. 展开更多
关键词 alkene Hydrogenation Benzyl Ether Benzyl Ester N-Benzyl Group
下载PDF
Efficient visible light initiated hydrothiolations of alkenes/alkynes over Ir_(2)S_(3)/ZnIn2S4:Role of Ir_(2)S_(3) 被引量:1
6
作者 Xinglin Wang Yuanyuan Li Zhaohui Li 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第3期409-416,共8页
The hydrothiolations of alkynes/alkenes with thiols is an atom-economic and thus attractive method for the constructions of C‒S bonds.Here Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposites with varied Ir_(2)S_(3)loadings were o... The hydrothiolations of alkynes/alkenes with thiols is an atom-economic and thus attractive method for the constructions of C‒S bonds.Here Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposites with varied Ir_(2)S_(3)loadings were obtained by one-pot solvothermal method from ZnCl_(2),InCl_(3)and thioacetamide with IrCl_(3).The loading of Ir_(2)S_(3)on the surface of ZnIn_(2)S_(4)promoted the hydrothiolations of alkenes and alkynes,with an optimum performance observed over 0.5 mol%Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposite.Based on the studies on the performance of several other cocatalysts(MoS2,NiS and Pd)loaded ZnIn_(2)S_(4)and the EIS analyses,it was proposed that the superior performance over Ir_(2)S_(3)/ZnIn_(2)S_(4)nanocomposite can be ascribed to an improved efficiency on the photogeneration of the thiyl radicals by loading Ir_(2)S_(3)as well as its inactivity for photocatalytic hydrogen evolution,a side reaction in the light initiated hydrothiolation reaction over ZnIn_(2)S_(4).This study not only demonstrates an efficient and green strategy to synthesize thiolated products under visible light based on semiconductor photocatalysis,but also provides some guidances for the design and development of photocatalytic systems for light induced organic syntheses. 展开更多
关键词 PHOTOCATALYSIS Ir_(2)S_(3)/ZnIn_(2)S_(4) alkeneS ALKYNES HYDROTHIOLATION
下载PDF
Ultrasonic-enhanced Stereoselective Debromination of vic-Dibromides to Alkenes with Metallic Zinc Powder in Aqueous Media
7
作者 LIPin-hua RAOWan-ping +1 位作者 WANGMin WANGLei 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2004年第5期598-601,共4页
Carbon-carbon double bond functional groups are often protected through a popular bromination/debromination method because of their reactivity. An ultrasonic-enhanced stereoselective debromination of vic-dibromides wi... Carbon-carbon double bond functional groups are often protected through a popular bromination/debromination method because of their reactivity. An ultrasonic-enhanced stereoselective debromination of vic-dibromides with metallic zinc powder in aqueous media has been developed, which generates E-alkenes with excellent yields. The reactivity of vic-dibromides decreases in the order of 1,2-dibromo-1,2-diphenylethane>1,2-dibromo-1-phenylethane>1,2-dibromo-1,2-dialkylethane. 展开更多
关键词 Stereoselective debromination vic-Dibromides alkeneS Metallic zinc Ultrasonic irradiation Aqueous medium
下载PDF
Asymmetric Baylis-Hillman Reaction between Chiral Activated Alkenes and Aromatic Aldehydes in Me_(3)N/H_(2)O/Solvent Medium
8
作者 Ke HE Zheng Hong ZHOU Hong Ying TANG Guo Feng ZHAO Chu Chi TANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第11期1427-1430,共4页
Chiral activated alkene, L-menthyl acrylate and (+)-N-α-phenylethyl acrylamide, induced asymmetric Baylis-HiUman reaction of aromatic aldehydes was realized at 25℃ for 7 days in Me3N/H2O/solvent homogeneous mediu... Chiral activated alkene, L-menthyl acrylate and (+)-N-α-phenylethyl acrylamide, induced asymmetric Baylis-HiUman reaction of aromatic aldehydes was realized at 25℃ for 7 days in Me3N/H2O/solvent homogeneous medium. The corresponding Baylis-Hillman adducts were obtained in good chemical yield with moderate to excellent diastereoselectivity (up to 99% de). 展开更多
关键词 Chiral activated alkene asymmetric Baylis-Hillman reaction aromatic aldehyde diastereoselectivity
下载PDF
Michael Addition of Amines to Activated Alkenes Promoted by Zn/NH_4Cl System
9
作者 KOU Jing-ping LU Yu-juan +1 位作者 LUO Xu-yang LI Ji-zhen 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2009年第4期461-464,共4页
A Zn/NH4Cl system was exploited at room temperature to promote the Michael addition reaction of various primary and secondary amines with α,β-unsaturated esters,nitriles,amides,and ketones to give the corresponding ... A Zn/NH4Cl system was exploited at room temperature to promote the Michael addition reaction of various primary and secondary amines with α,β-unsaturated esters,nitriles,amides,and ketones to give the corresponding saturated amines under the mild condition in high yield. 展开更多
关键词 Michael addition AMINES Activated alkenes Zn/NH4Cl system
下载PDF
A DFT Study of Alkenes and Alkynes Reacting with H-GaN (0001) Surface
10
作者 胡春丽 陈勇 +1 位作者 李俊篯 章永凡 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第1期125-131,共7页
The addition reactions of alkenes and alkynes to the H-terminated GaN (0001) surface with a Ga dangling-bond have been studied employing periodic density functional theory (PDFT) calculations. Detailed information... The addition reactions of alkenes and alkynes to the H-terminated GaN (0001) surface with a Ga dangling-bond have been studied employing periodic density functional theory (PDFT) calculations. Detailed information on the reaction pathways of these alkenes and alkynes with H-GaN (0001) surface is provided, which indicates that the reactions contain two steps separated by the metastable intermediates: elementary addition reaction and H-abstraction process. From the energy curves, the reactions are clearly viable in the cases of ethene, styrene and phenylacetylene; while for ethyne, the H-abstraction barrier is higher than the desorption barrier of the intermediate, so the adsorbed C2H2 in intermediate is more likely to be desorbed back into the gas phase than to form a stable adsorbed species. Furthermore, it is obvious that for either alkenes or alkynes, the systems substituted by phenyl have more stable intermediates because π conjugation could improve their stabilities. 展开更多
关键词 alkeneS ALKYNES H-GaN (0001) surface DFT reaction pathway
下载PDF
Chiral Salen Manganese Complex Immobilized on SBA-15:A New Heterogenized Enantioselective Catalyst forthe Epoxidation of Alkenes
11
作者 XinMeiZHENG YanXingQI XiaoMingZHANG JiShuanSUO 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第6期655-658,共4页
Jacobsen's catalyst was immobilized onto SBA-15 by multi-step grafting, and this heterogenized catalyst exhibited comparable catalytic performance with the corresponding homogeneous counterpart for the epoxidation... Jacobsen's catalyst was immobilized onto SBA-15 by multi-step grafting, and this heterogenized catalyst exhibited comparable catalytic performance with the corresponding homogeneous counterpart for the epoxidation of alkenes, and the catalyst could be recycled effectively several times. 展开更多
关键词 SBA-15 chiral salen Mn(Ⅲ) complex alkeneS asymmetric epoxidation.
下载PDF
'STEREOSELECTIVE SYNTHESIS OF TRISIJBSTITUTED ALKENES VIA,TITANOCENOCYCLES
12
《Chemical Research in Chinese Universities》 SCIE CAS 1986年第1期25-32,共8页
By previously reported modified Masai-Rausch method of synthesizing titanocenocycles,followed by acid hydrolysis,trisubstituted al-kenes were synthesized,yields obtained are higher than that reported in literatures.St... By previously reported modified Masai-Rausch method of synthesizing titanocenocycles,followed by acid hydrolysis,trisubstituted al-kenes were synthesized,yields obtained are higher than that reported in literatures.Starting from unsymmetrical alkyne substrates,twelve different types of substituted alkenes were synthesized,among which only two were found single component,others were of mixed isomers.Beside conventional analytical methods,the NMR spectral analysis of titanocenoheterocycle intermediates and the products were used to identify the isomeric structures as well as their relative contents. 展开更多
关键词 OC STEREOSELECTIVE SYNTHESIS OF TRISIJBSTITUTED alkeneS VIA TITANOCENOCYCLES VIA
下载PDF
INSERTION OF PTC-GENERATED DICHLOROCARBENE INTO C-B BO ND.A FACILE SYNTHESIS OF KETONES FROM ALKENES VIA ORGANOBORATES
13
作者 De Jie ZHAO Tian Yi KE Chang Mei KE Zi Xing SHAN Chemistry Department,Wuhan University,Wuhan 430072 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第6期471-474,共4页
The insertion of dichlorocarbene generated from chloroform by Phase Transfer Catalysis(PTC)into carbon-boron bond of dialkylborate anions 3,obtained by method A and B,resulted in the formation of the inter- mediates 5... The insertion of dichlorocarbene generated from chloroform by Phase Transfer Catalysis(PTC)into carbon-boron bond of dialkylborate anions 3,obtained by method A and B,resulted in the formation of the inter- mediates 5,which were oxidized with alkaline hydrogen peroxide to give the corresponding dialkylketones in 36-77.9% yields. 展开更多
关键词 CI INSERTION OF PTC-GENERATED DICHLOROCARBENE INTO C-B BO ND.A FACILE SYNTHESIS OF KETONES FROM alkeneS VIA ORGANOBORATES PTC CHC TEBA OH BO ND VIA
下载PDF
Safe Hydroformylation of Aliphatic Alkene in a Flow Reactor
14
作者 Hisashi Masui Eiki Honda +2 位作者 Sakura Niitsu Mitsuru Shoji Takashi Takahashi 《International Journal of Organic Chemistry》 2018年第1期135-141,共7页
Despite hydroformylation being a very efficient method for the transformation of alkenes, it is not commonly employed in laboratories owing to the flammable/toxic nature of hydrogen and carbon monoxide gases and the n... Despite hydroformylation being a very efficient method for the transformation of alkenes, it is not commonly employed in laboratories owing to the flammable/toxic nature of hydrogen and carbon monoxide gases and the necessity of high-pressure equipment in a batch system. Flow chemistry often raises the safety profiles against high-pressure and toxic gases because the diameter of the flow reactor is small. Herein, we show that aliphatic alkenes can be safely hydroformylated in a flow reactor. In our flow method, although the target hydroformylated product was obtained in a low yield (19%), toxic gases were safely treated using a flow reactor. Better yields could possibly be achieved by recycling of the unreacted alkene. 展开更多
关键词 HYDROFORMYLATION Flow Synthesis alkene Carbon MONOXIDE ALDEHYDE
下载PDF
STUDY ON Cp_2TiCl_2/Fe-INITIATED ADDITION OF 2-HALOTETRAFLUOROETHYL IODIDES TO ALKYNES AND ALKENES
15
作者 Chang Ming HU Jian CHEN Yao Ling QIU Shanghai Institute of Organic Chemistry,Academia Sinica,345 Lingling Lu,Shanghai 200032. 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第10期853-854,共2页
Initiated by CP_2TiCl_2/Fe redox system,2-halotetrafluoroethyl iodides readily reacted with alkynes or alkenes to give 1:1 adducts in good to excellent yields.
关键词 Fe STUDY ON Cp2TiCl2/Fe-INITIATED ADDITION OF 2-HALOTETRAFLUOROETHYL IODIDES TO ALKYNES AND alkeneS Hg
下载PDF
A New Method for the Transformation of Alkenes intoα, β-Unsaturated Ketones via Cycloaddition with Dichloroketene
16
作者 徐福培 ThsanErden JamesR.Keeffe 《Advances in Manufacturing》 SCIE CAS 1997年第3期257-259,共3页
A new synthetic method is described here to obtain α, β-unsaturated ketones through alkenes through a sequence involving f (1) cycloaddition of alkenes with dichloroketene, (2) dechlorination of adducts, (3)acidprom... A new synthetic method is described here to obtain α, β-unsaturated ketones through alkenes through a sequence involving f (1) cycloaddition of alkenes with dichloroketene, (2) dechlorination of adducts, (3)acidpromoted ring-opening isomerization ofcyclobutanones in CF3 CO2H. 展开更多
关键词 alkenes. α β-unsaturated ketones cycloaddition dichloroketene
下载PDF
ORGANOPHOSPHINE INITIATED REACTION OF PERFLUOROALKYL IODIDES WITH ALKENES
17
作者 Wei Yuan HUANG Han Zhong ZHNG (Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,345 Lingling Lu,Shanghai 200032) 《Chinese Chemical Letters》 SCIE CAS CSCD 1990年第2期153-154,共2页
perfluoroalkyl iodides reacted with alkenes in acetonitrile solu- tion containing catalytic amount of organophosphine under mild condition to give the corresponding adducts in moderate to good yields.Reaction was show... perfluoroalkyl iodides reacted with alkenes in acetonitrile solu- tion containing catalytic amount of organophosphine under mild condition to give the corresponding adducts in moderate to good yields.Reaction was shown to involve a free radical mechanism. 展开更多
关键词 ORGANOPHOSPHINE INITIATED REACTION OF PERFLUOROALKYL IODIDES WITH alkeneS
下载PDF
Visible Light-Induced[3+2]Annulation Reaction of Alkenes with Vinyl Azides:Direct Synthesis of Functionalized Pyrroles 被引量:1
18
作者 Ming Yang Xin-Yu Wang +1 位作者 Jie Wang Yu-Long Zhao 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第2期151-156,共6页
A photocatalytic[3+2]annulation of alkenes with vinyl azides was developed under irradiation by visible light in the presence of organic dye photocatalysts.Broad substrate scope and high functional group tolerance wer... A photocatalytic[3+2]annulation of alkenes with vinyl azides was developed under irradiation by visible light in the presence of organic dye photocatalysts.Broad substrate scope and high functional group tolerance were demonstrated by more than 50 examples.The reaction provides a novel and efficient method for the synthesis of polyfunctionalized pyrroles under very mild metal-free conditions without other additives. 展开更多
关键词 Photocatalysis Vinyl azides alkeneS PYRROLES ANNULATION Radical reactions
原文传递
Recent Advances in Enantioselective Reactions of Terminal Unactivated Alkenes 被引量:1
19
作者 Qihang Guo Xuzhong Shen Zhan Lu 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第7期760-776,共17页
α-Olefins as aliphatic terminal alkenes could be obtained easily from numerous contemporary synthetic reactions as well as petro-chemical industry,and also found in natural products.Compared to the alkenes attaching ... α-Olefins as aliphatic terminal alkenes could be obtained easily from numerous contemporary synthetic reactions as well as petro-chemical industry,and also found in natural products.Compared to the alkenes attaching the directing groups or activating group,the catalytic asymmetric reaction of unactivated terminal alkenes presents great challenges due to the weak electron effect and small steric hindrance effect.This review mainly summarizes the latest progress of the asymmetric reaction of unactivated terminal olefins since 2016. 展开更多
关键词 Asymmetric catalysis Terminal unactivated alkenes Hydrofunctionalization Difunctionalization Metal-catalyzed
原文传递
Low molecular weight alkane-fed solid oxide fuel cells for power and chemicals cogeneration
20
作者 Ermete Antolini 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第5期711-735,I0015,共26页
This paper presents a review of low molecular weight alkane-fed solid oxide fuel cells(SOFCs),which,unlikely the conventional use of SOFCs for only power production,are utilized to cogenerate produce useful chemicals ... This paper presents a review of low molecular weight alkane-fed solid oxide fuel cells(SOFCs),which,unlikely the conventional use of SOFCs for only power production,are utilized to cogenerate produce useful chemicals at the same time.The cogeneration processes in SOFC have been classified according to the different types of fuel.C_(2)and C_(3)alkenes and synthesis gas are the main cogenerated chemicals together with electricity.The chemicals and energy cogeneration in a fuel cell reactor seems to be an effective alternative to conventional reactors for only chemicals production and conventional fuel cells for only power production.Although,the use of SOFCs for chemicals and energy cogeneration has proved successful in the industrial setting,the development of new catalysts aimed at obtaining the desired chemicals together with the production of a high amount of energy,and optimizing SOFC operation conditions is still a challenge to enhance system performance and make commercial applications workable. 展开更多
关键词 Solid oxide fuel cells ALKANE alkene SYNGAS COGENERATION
下载PDF
上一页 1 2 10 下一页 到第
使用帮助 返回顶部