Copper‐Catalyzed Oxidative Transformation of Aryl Propargylic Azides to Aryl Propiolonitriles

A concise copper(I)‐catalyzed oxidative transformation of aryl propargyl azides to aryl propiolonitriles has been developed. Aryl propiolonitrile derivatives can be obtained in moderate to good yields by this strategy. An oxidative Schmidt rearrangement is involved in this transformation.     

聚乙二醇(200)双甲基丙烯酸酯的合成

以PEG-200和甲基丙烯酸为主要原料,同时加入阻聚添加剂FA03,合成PEG-200双甲基丙烯酸酯。通过正交实验考察了原料配比、催化剂用量、阻聚剂用量、反应时间等因素对产率的影响,最佳工艺条件为PEG- 200与甲基丙烯酸摩尔比为1:2．1;催化剂对甲苯磺酸用量为醇酸总质量的2％;阻聚剂FY51用量为甲基丙烯酸质量的0．2％;反应时间为5 h;阻聚添加剂FA03用量为醇酸总质量的0．2％。最终产品酸值小于0．5 mg KOH／ g,w(固体分)>98％(105℃,20 min),产率大于82％。     

Click Chemistry: Copper Clusters Catalyse the Cycloaddition of Azides with Terminal Alkynes

Air‐stable copper nanoclusters are good catalysts in the Cu(I)‐catalysed “click” cycloaddition of azides with terminal alkynes to give 1,4‐disubstituted 1,2,3‐triazoles. No additional base or reducing agent is required. The reaction kinetics using various copper catalyst types and the function of copper particles in this system are studied and discussed.     

KO~tBu促进的有机叠氮和末端炔烃的环加成反应改进研究

文章系统研究了叔丁醇钾促进下芳基叠氮和取代苯乙炔的环加成反应。在等摩尔数的叔丁醇钾作用下,当溶剂为DMF时,反应效果最佳,产率高达92%。其他的芳基叠氮和苯乙炔的反应研究结果表明,芳基叠氮和苯乙炔在此环加成反应中具有良好的反应适应性。     

Gold(I)‐Catalyzed Synthesis of Tetrahydrocarbazoles via Cascade [3,3]‐Propargylic Rearrangement/[4+2] Cycloaddition of Vinylindoles and Propargylic Esters

A gold(I)‐catalyzed cascade [3,3]‐propargylic rearrangement and [4+2] cycloaddition reaction of 2‐vinylindoles with propargylic esters is reported. The reaction leads to the synthesis of highly substituted tetrahydrocarbazole derivatives in high yields and diasteroselectivities. Furthermore, a preliminary screening for an asymmetric version of this reaction is described.

     

Silver‐Catalyzed Cyclization of Propargylic Amides to Oxazolines

A ligand‐accelerated effect is observed in the cyclization of propargylic amides catalyzed by bis(pyridyl)silver(I) complexes, with an unexpected reversal of electronic demand to the analogous N H addition reaction. The catalyst was found to be effective for internal alkyne substrates, offering exclusive selectivity for the 5‐exo‐dig product. Differences in selectivity profile between gold‐ and silver‐catalyzed processes are highlighted and discussed.

     

炔丙基醇类化合物的无溶剂微波法合成

描述了一种以端基炔和酮类化合物为原料,在叔丁醇钾为催化剂的无溶剂条件下,炔丙基醇类化合物的微波合成方法;其产物结构经1H NMR表征。     

Study of CO2 and CH4 Permeation Properties through Prepared and Characterized Blended Pebax-2533/PEG-200 Membranes

This study demonstrates how incorporation of polyethylene glycol (PEG-200) into poly (ether-block-amide) (Pebax-2533) can improve the prepared membrane performance in separating CO₂from CH₄. Additionally, the effect of various PEG-200 loadings on CH₄and CO₂permeability and CO₂/CH₄selectivity values was investigated. The prepared membranes were examined using Fourier transform infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. Permeation experiments of the gasses through the neat Pebax and the blended (Pebax-2533/PEG-200) membranes were carried out at a temperature of 25 ^∘C and pressure range of 2 to 10 bar. The gas permeation experiments indicated that the performance of blended membranes is better than that of the neat membrane. As an example, CO₂permeability and ideal CO₂/CH₄selectivity values for the blended membrane with 40 wt.% of PEG-200 loading are 351.65 and 9.17 Barrer, while those values for the neat membrane are 187.54 and 7.28 Barrer, respectively.

     

On the Stereochemistry of Organocopper Mediated Conversion of Propargylic Esters to Allenes

Using a vitamin D-related steroidal CD fragment as a stereochemical probe, the effect of various factors on the stereochemical course of the organocopper induced conversion of propargylic esters to allenes has been studied. In all cases, an anti mode of attack by the organocopper species was found to be preferred. The effectiveness of Gilman-type reagents (R₂CuLi) versus that of the Lipshutz-type higher-order mixed cuprate systems (R₂CuCNLi₂) in promoting the reaction was also studied.     

A Mild and Versatile Method for the Synthesis of Alkyl Ethers from Methoxymethyl Ethers and Application to the Preparation of Sterically Crowded Ethers

A mild and divergent route for the synthesis of alkyl ethers from methoxymethyl (MOM) and methoxyethyl (ME) ether derivatives via pyridinium‐type salt intermediates has been developed. The addition of organocuprates to the salts afforded the corresponding alkyl ethers, including highly crowded ones, in high yields even in the presence of acid‐ or base‐sensitive functional groups.     

从啶虫丙醚到二卤代丙烯类杀虫剂的研发

具二卤代丙烯醚结构的啶虫丙醚是一种结构特异、作用机制独特的新颖杀虫剂。它的成功开发,也促使了人们对二卤代丙烯醚类杀虫剂的研究、开发。     

在近临界水中由叠氮化合物还原制备胺

在近临界水(250℃)中用锌将叠氮化合物还原为胺。用IR和1HNMR对产物进行了表征。研究了温度、摩尔比和反应时间对产率的影响,最佳反应条件为:n(Zn)∶n(azide) =3∶1,温度250℃,时间3h,胺产率可达90%。     

PEG-6000促进下合成安息香反应研究

以VB1为催化剂,加入辅助剂PEG-6000,顺利合成了安息香,结果表明:安息香产率高,实验重现性好,成功率达100％。     

Substituent Effects in the Intramolecular Photocyclization of o-Allylphenols to Cyclic Ethers

UV irradiation, in benzene or cyclohexane, of substituted ortho-allylphenols to form cyclic ethers (presumably through an ionic mechanism) does not show any correlation with the pKa of the excited states of the phenols in aqueous solution.     

橄榄油PEG-7酯类在洗涤类化妆品中的应用研究

对橄榄油PEG-7酯类在洗涤类化妆品中的应用进行了研究。探讨了橄榄油PEG-7酯类对洗涤类化妆品理化性能的影响。结果表明:橄榄油PEG-7酯类具有良好的配伍性能,加入量范围对制品的稳定性、黏度及p H值等均无影响,但用量大时会使制品的起泡性能下降。同时,试用结果表明,相比普通制品,橄榄油PEG-7酯类能降低制品的潜在刺激性,明显改善制品使用效果。     

丙二醇单烷基醚的合成

介绍了低温、常压下用环氧丙烷与低级脂肪醇在一种BF3改进催化剂作用下合成丙二醇单烷基醚的方法。通过实验考察了影响转化率的因素 ,并对两种不同产物的合成进行比较 ,给出了适宜的反应条件和经济的生产过程     

Pulping Reactions of Vinyl Ethers

Model studies suggest that vinyl ethers are in equilibrium with quinone methides at 170°C in aqueous NaOH and that 25–30% of the vinyl ethers undergo fragmentation during kraft and AQ pulping.     

Enantioselective Synthesis of Alkyl Allyl Ethers via Palladium-Catalyzed Redox-Relay Heck Alkenylation of O-Alkyl Enol Ethers

Herein we report a transformation that generates an array of enantiomerically enriched, alkyl allyl ethers. Cyclic, acyclic, and heteroatom-bearing alkenyl triflates undergo an enantioselective, palladium-catalyzed C−C bond formation with diverse acyclic O-alkyl enol ethers in good yields and excellent enantioselectivities.