手性酮催化的烯烃不对称环氧化反应

手性酮是催化非官能化烯烃不对称环氧化的一类重要催化剂 ,它与过氧硫酸氢钾可原位产生对贫电子和富电子烯烃均很有效的氧化剂———手性二氧杂环丙烷 .综述了各种结构的手性酮在反式烯烃、三取代烯烃和顺式烯烃等的不对称环氧化反应中的应用研究进展 ,总结了手性酮结构及反应条件对其催化活性和不对称诱导作用的影响     

Addition of lithium aluminium hydride to olefins catalyzed by zirconium tetrachloride: A convenient route to alkanes and 1-haloalkanes from 1-alkenes

Lithium aluminium hydride adds to olefins in the presence of zirconium tetrachloride under mild conditions. This facile reaction offers a convenient laboratory method for the hydrogenation of olefins or for the preparation of 1-haloalkanes from olefins in high yield. Unstrained internal olefins appear to be unreactive.     

Production of Low-carbon Light Olefins from Catalytic Cracking of Crude Bio-oil

Low-carbon light olefins are the basic feedstocks for the petrochemical industry. Catalytic cracking of crude bio-oil and its model compounds (including methanol, ethanol, acetic acid, acetone, and phenol) to light olefins were performed by using the La/HZSM-5 catalyst. The highest olefins yield from crude bio-oil reached 0.19 kg/(kg crude bio-oil). The reaction conditions including temperature, weight hourly space velocity, and addition of La into the HZSM-5 zeolite can be used to control both olefins yield and selectivity. Moderate adjusting the acidity with a suitable ratio between the strong acid and weak acid sites through adding La to the zeolite effectively enhanced the olefins selectivity and improved the catalyst stability. The production of light olefins from crude bio-oil is closely associated with the chemical composition and hydrogen to carbon effective ratios of feedstock. The comparison between the catalytic cracking and pyrolysis of bio-oil was studied. The mechanism of the bio-oil conversion to light olefins was also discussed.     

Sulfonation chemistry of some small molecule models of EPDM rubbers. II. The structure of intermediate adducts

As previously reported, our initial investigation was concerned with the bicyclic olefins, ethylidene norbornane, and dihydrodicyclopentadiene. The former produced a skeletally rearranged γ-sultone and the latter an allylic sulfonic acid. In an attempt to further clarify the mechanisms of the sulfonation of these two models and to extend the study to models of other types of EPDM, we have now examined the sulfonation of several other model olefins. In addition to the bicyclic olefins reported previously, we have studied the sulfonation of monocyclic type II and III olefins and cyclic type I and type II olefins. The results showed that the bicyclic olefins behaved differently from their monocyclic analogs reinforcing earlier speculation as to a synchronous reaction mechanism. Exocyclics gave allylic sulfonic acids while endocyclics produced β-sultones, which is the exact reverse of what was observed for the bicyclic counterparts. Acyclic type II olefins produced “stable” β-sultones, and the influence of the sulfonating reagent on the subsequent chemistry is discussed. Type I olefins, curiously, gave a complex mixture of initial products which tended to rearrange to essentially a single thermodynamic product. The results of the investigation suggest that based on these models, each of the three major types of EPDM should have a different sulfonation mechanism.     

FCC汽油催化裂解生产低碳烯烃的研究

利用小型固定流化床实验装置研究了催化裂化（FCC）汽油在专门开发的多产低碳烯烃催化剂上的裂解性能。研究表明,反应温度对原料转化率、总低碳烯烃产率的影响最大,剂油比和水油比对低碳烯烃的产率影响较小,而随着重时空速的增大,总低碳烯烃产率略有降低;确定了FCC汽油催化裂解制低碳烯烃的实验室最优反应条件,即反应温度、剂油比、重时空速和水油比分别为660℃、12、15h^-1和0.8。根据反应条件与裂解产物的关系提出了催化裂解反应深度函数,并建立裂解产物产率与催化裂解反应深度函数之间的关联模型。随催化裂解反应深度函数的增加,乙烯产率持续增加,而丙烯和丁烯产率出现最大值,利用此模型可以对产物产率进行预测。     

Palladium-catalyzed highly regioselective and stereoselective decarboxylative arylation of unactivated olefins with aryl carboxylic acids

Palladium(II)-catalyzed highly regioselective and stereoselective decarboxylative arylation of unactivated olefins with aryl carboxylic acids has been developed. This method is applicable to a variety of unactivated olefins, including allylamides, long chain functionalized olefins and purely aliphatic olefins, leads to the formation of linear E-configured products in high yields. Both electron-rich and electron-deficient aryl carboxylic acids are suitable arylation reagents. It was found that the choice of solvent, catalyst precursor and oxidant had an important influence on reaction efficiency. As a co-solvent and ligand, DMSO is critical to catalysis. This chemistry expands the scope of decarboxylative arylation of olefins with aryl carboxylic acids, and provides a rapid access to useful linear arylation products of unactivated olefins.     

改性ZSM-5分子筛催化裂解湛江等鞭金藻制取低碳烯烃(英)

研究了湛江等鞭金藻(Isochrysis zhanjiangensis)在改性ZSM-5分子筛上催化裂解制取低碳烯烃的过程.与热裂解过程相比,湛江等鞭金藻催化裂解可以得到更高的低碳烯烃选择性和收率.同时还研究了湛江等鞭金藻中不同油脂和藻渣的催化裂解.结果表明,微藻中的油脂能有效转化为烯烃,其中中性脂的烯烃收率最高,可达36.7%.不同溶剂抽提后得到的藻渣也可转化为低碳烯烃,但收率远低于微藻中的油脂.微藻中的油脂,特别是中性脂,是烯烃的主要贡献者,提高微藻中的中性脂含量能够得到更高的低碳烯烃收率.     

Chlorination of aliphatic hydrocarbons, aromatic compounds, and olefins in subcritical carbon tetrachloride

The reactions of various substrates including aliphatic hydrocarbons, aromatic compounds, and olefins were investigated in subcritical carbon tetrachloride. Ketones and sulfones were stable under the employed conditions. The coupling adducts between olefins and carbon tetrachloride were obtained from the reactions of olefins.     

合成气催化转化直接制备低碳烯烃研究进展

合成气直接催化转化制备低碳烯烃是C1化学与化工领域中一个极具挑战性的研究课题,具有流程短、能耗低等优势,已成为非石油路径生产烯烃的新途径。直接转化方式主要包括经由OX-ZEO双功能催化剂直接制低碳烯烃的双功能催化路线以及经由费托反应直接制备低碳烯烃的FTO路线。综述简述了近年来在合成气直接制备低碳烯烃方面的研究进展,重点讨论了低碳烯烃的形成机理、新型催化剂的研发及助剂对其催化性能的影响,并对合成气直接制烯烃的未来进行了展望。     

烯烃在催化裂化催化剂上反应机理的初步研究

在自制的微反-色谱装置上,进行了单体烯烃和催化裂化汽油在不同条件下的催化裂化反应实验。对单体烯烃的裂化反应规律和汽油中的烯烃在半再生催化剂和待生催化剂上的催化裂化反应规律进行对比分析。结果表明,单体烯烃反应中,C6及C6以下的烯烃主要发生骨架异构和双键异构反应,氢转移和直接裂化反应发生的较少。C7以上的烯烃95%以上发生转化,高温下直接裂化生成C3、C4,氢转移和异构化比率较大。汽油中的烯烃转化主要集中在C7以上,烯烃之间存在一定的交互作用,单体烯烃的催化裂化反应规律可以初步预测汽油中烯烃的转化。催化剂上的结焦类型对汽油中的烯烃的转化方式没有影响。     

Cu-Fe基催化剂上合成气直接制取低碳烯烃的研究

我们采用浸渍法制备了γ-Al2O3负载的Cu-Fe基催化剂,并结合其反应性能和XRD、H2-TPR和XPS等表征结果研究了其催化合成气直接制低碳烯烃的反应行为.结果表明,合成气直接制低碳烯烃Cu-Fe基催化剂的活性组分Cu和Fe之间存在明显的协同效应,Cu-Fe基催化剂表现出优异的合成气直接制低碳烯烃反应性能;Cu基催化剂中引入少量Fe组分明显提高了活性组分Cu的分散度,促进了Cu活性组分的还原,进而有利于催化剂反应性能的改进.初步推断Cu-Fe基催化剂上合成气转化生成低碳烯烃的主要反应历程为CO加氢生成含氧化合物(醇醚等)后再脱水生成低碳烯烃.     

Iodoamidation of olefins with chloramine salts and iodine in aqueous media

An efficient, unique, and convenient method for the iodoamidation of olefins with chloramine salts and I(2) in aqueous media is described. This method was applicable to a wide range of olefins, including aromatic, aliphatic, and electron-deficient olefins.     

Ruthenium-catalyzed oxidative cleavage of olefins to aldehydes.

Three oxidation protocols have been developed to cleave olefins to carbonyl compounds with ruthenium trichloride as catalyst (3.5 mol %). These methods convert olefins that are not fully substituted to aldehydes rather than carboxylic acids. While aryl olefins were cleaved to aromatic aldehydes in excellent yields by using the system of RuCl3-Oxone-NaHCO3 in CH3CN-H2O (1.5:1), aliphatic olefins were converted into alkyl aldehydes with RuCl3-NaIO4 in 1,2-dichloroethane-H2O (1:1) in good to excellent yields. It is noteworthy that terminal aliphatic olefins were cleaved to the corresponding aldehydes in excellent yields by using RuCl3-NaIO4 in CH3CN-H2O (6:1).     

三苯甲基取代烯烃的环氧化研究

合成了6种三苯甲基取代烯烃. 以二甲基二氧杂环丙烷作为主要氧化剂, 在催化剂(R,R)-Salen Mn(III)的催化下, 进行不对称环氧化, 其不对称环氧化产物ee值较高(81%). 初步研究表明, 二甲基二氧杂环丙烷(DMD)和(R,R)-Salen Mn(III)的环氧化体系对于含亚甲基的三苯甲基取代的烯烃的氧化产率高但对映选择性差, 对于不含亚甲基的三苯甲基取代的烯烃的氧化产率低但对映选择性好.     

Thiol-catalyzed acyl radical cyclization of alkenals

Thiol-catalyzed direct generation of acyl radicals and their intramolecular addition to olefins of alkenals gave 2-substituted five- and six-membered cyclic ketones in reasonably good yields. The combination of odorless tert-dodecanthiol and AIBN or V-40 was the initiator of choice among surveyed radical generators for the cyclization of alkenals. Aldehydes having electron-deficient olefins cyclized more easily than those having unactivated olefins.     

Alder-ene reaction of aryne with olefins

A novel intermolecular Alder-ene reaction based on aryne and olefins was developed. We performed this transformation under mild conditions such as at room temperature, and this reaction displayed high selectivity and good yields only in the presence of CsF. Hence, the intermolecular Alder-ene reaction of aryne with olefins provides an effective route to synthesize derivatives of olefins.     

Catalytic oxidative cleavage of olefins promoted by osmium tetroxide and hydrogen peroxide

Hydrogen peroxide was employed as the terminal oxidant in the osmium tetroxide mediated oxidative cleavage of olefins, producing the corresponding aldehyde and ketone products. Aryl olefins are cleaved in good to excellent yield regardless of arene electronics. Alkyl olefins cleave in moderate to good yield for di- and tri-substituted alkenes.     

Palladium-catalyzed double arylations of terminal olefins in acetic acid

A palladium-catalyzed Heck diarylation of terminal olefins under ligand-free conditions in acetic acid is described. This procedure allows double arylation of terminal olefins affording trisubstituted olefins in good to excellent yields. The methodology is applicable to the coupling of both electron-deficient and electron-rich aryl iodides leading to symmetrical and unsymmetrical β,β-diarylated alkenes.     

Selective dimerization,oligomerization, homopolymerization and copolymerization of olefins with complex organometallic catalysts

Review embarrasses the problems of low molecular weight olefins (ethylene and propylene) selective oligomerization to butene-1, hexene-1, octene-1, 4-methylpentene-1; selective polymerization of olefins to obtain polymers with a given molecular mass, molecular mass distribution, branching (for the polyethylene), chain structure [atactic, iso-, syndio-, gemiisotactic, stereoblock type and containing terminal vinyl and vinylidene bonds (for polypropylene)]; “live” homo-and copolymerization of olefins, and alternating copolymerization of olefins in the presence of complex organometallic catalysts.     

Access to macrocyclic endocyclic and exocyclic allylic alcohols by nickel-catalyzed reductive cyclization of ynals

Ni-catalyzed reductive macrocyclizations of ynals are reported. Disubstituted alkynes afford either endocyclic or exocyclic allylic alcohols depending on the ligand. Phosphine ligands favor the formation of endocyclic olefins, whereas N-heterocyclic carbene ligands favor the formation of exocyclic olefins. Terminal alkynes provide 1,2-disubstituted olefins with N-heterocyclic carbene ligands.