浆态相低温甲醇合成用的CuCr／CH3ONa催化体系的反应性能

在液相介质为二甲苯，甲醇或液体石蜡，温度１００～１４０℃，压力３．５～４．７ＭＰａ条件下，使用Ｈ２／ＣＯ＝２的合成气，在１Ｌ搅拌釜内考察了自制的ＣｕＣｒ／ＣＨ３ＯＮａ催化体系的浆态相低温甲醇合成的反应性能，结果表明液相介质以二甲苯为佳，ＣＯ转化率随压力而升高，温度以１２０℃为宜。４４ｈ的连续运转表明以ＣＯ转化率为代表的催化体系的反应性能基本稳定。     

鼓泡浆态反应器中低温甲醇合成的探索

为了开发低温液相甲醇合成新工艺,使用CuCr／CH3ONa催化体系,在直径40mm的鼓泡浆液反应器中考察了低温甲醇合成的反应性能。鼓泡浆液反应器使用的浆液由铜铬催化剂、甲醇钠溶液、乳化剂OP-10和液相介质二甲苯组成。实验结果表明在90℃～110℃、4．8MPa和操作气速0．2cm／s下,前9h的CO平均转化率达到78％。甲醇是反应的主要产物。与搅拌釜中的实验结果比较,鼓泡浆液反应器的反应效率为搅拌釜的80％。这是由于甲醇钠的消耗和乳化剂的负效应所致。实验结果示范了鼓泡浆态反应器中低温甲醇合成的可行性。     

C02（CO）8催化苯乙烯氢酯基化制α-苯基丙酸酯研究

以Co2（CO）8为催化剂,对苯乙烯与CO及甲醇氢酯基化反应制α-苯基丙酸甲酯的反应进行了研究,并根据实验结果提出了可能的催化反应机理．考察了催化剂用量、配体、溶剂、CO压力及反应温度等因素对氢酯基化反应的影响．结果表明：以甲苯为溶剂,在n（Co2（CO）8）／n（苯乙烯）=0．06,吡啶为配体且n（吡啶）／n（Co）=2,CO压力6．0MPa、反应温度95℃的较佳条件下反应12h,苯乙烯的转化率接近100％,α-苯基丙酸甲酯的收率达到89．07％,异正比24．35．     

PVP—PdCI2—CuCI2／PPh3体系催化α—（6‘甲氧基—2’—萘基）乙醇羰化反应研究

首次用高分子负载型双金属催化剂PVP－PdCI2-CuCI2/PPh3体系催化α-（6'甲氧基－2'－萘基）乙醇与一氧化碳及甲醇进行碳化反应制备萘普生甲酯,分别对温度、压力、时间、P／Pd比等影响因素进行了考察,在反应条件为100℃、16-20h、CO压力为4．0MPa、P/Pd＝3时,转化率可达97．4％,异正比为14．4,在同样条件下制备萘普生乙酯及萘普生异丙酯,转化率及选择性均有明显下降。另外,该催化剂体系也可催化其它类型α－芳基乙醇的羰化反应。     

NOx催化的甲烷气相氧化反应

 考察了没有固体催化剂时NOx对甲烷气相氧化的催化作用，并用原位红外光谱研究了CH4－O2－NOx体系随温度的变化．实验结果表明，NOx对甲烷气相氧化有很高的催化活性．在20％CH4－10％O2体系中加入0．05％～0．2％的NO后，反应温度可降低200～300℃，在650～700℃下反应时，CH4转化率和CO选择性可分别达到38％和90％，产物中的n（H2）／n（CO）比为0．4～0．7．反应产物中可观察到有甲醛、甲醇和乙烯等，通过改变反应条件可以控制各组分的相对浓度．     

闪蒸分离的低温液相甲醇合成的研究

为了强化传质和反应操作,同时实现反应产物与浆液的分离,使用CuCr/CH3ONa催化体系,在鼓泡浆液反应器(BCSR)、闪蒸塔(FC)和浆液循环泵组成的反应系统（BCSR FC）中考察了低温甲醇合成的反应性能。初始浆液由铜铬催化剂、甲醇钠溶液、乳化剂OP 10和液相介质二甲苯组成。在BCSR:4.2MPa～4.6MPa,110℃～120℃(反应段)100℃～110℃(扩大段),入口气速0.35cm/s～0.40cm/s;FC:0.25MPa～0.40MPa,80℃～90℃,浆液循环量50L/h下, 100h实验期间,合成气转化率、CO转化率和H2转化率分别从最高的71.0％、79.1％和67.5％降到17.8％、35.0%和12.1%。催化体系失活的主要原因是CH3ONa 和MeF反应生成甲酸钠。液体产物由DME 1.23%、甲醇79.52%、MeF 19.25%组成。甲醇＋MeF的选择性大于98％。以系统中催化剂为基准,液体产物的产率则为0.166g/gcat·h; BCSR中CuCr催化剂的液体产物的产率为0.336g/gcat·h。     

微乳法制备Au/Al2 O3 催化剂及其催化氧化CO性能的研究

用Tx-100／正己醇／环己烷／水的W／O微乳体系,合成了一系列Au／Al2O3催化剂。考察了焙烧温度、沉淀剂种类、搅拌方式等对Au／Al2O3,催化氧化CO活性的影响。结果表明：以氨水为沉淀剂,机械搅拌,600℃焙烧制得的Au／Al2O3,显示出较好的CO氧化性能。当反应温度为100℃时,CO转化率达85．0％,240℃时转化率达96．0％。XRD,DTA,TPR和TEM等表征表明：低温焙烧的催化剂,大部分载体Al2O3为无定型,对催化活性不利;焙烧温度过高,可能造成金微粒的团聚烧结,使其活性下降;由较强烈的搅拌方式制得的Au／Al2O3经适宜温度焙烧,可获得金粒尺寸较小、CO催化氧化活性较高的Au／γ-Al2O3催化剂。     

配合Pd催化剂薄荷醇与异丁烯羰基合成Validol

用PdCL2(PPh3)2/PPh3/P-CH3C6H4SO3H复合催化体系,在间歇高压釡中,以二甲苯为溶剂,在一定的反应温度、CO/H2压力和薄荷醇与异丁烯浓度下,研究了主催化剂浓度和各种助催化剂的配比对薄荷醇转化率和反应速度的影响.在适宜的催化体系和反应体系中,进行了反应物的转化率、Validol的选择性和收率与反应时间关系实验.对98%以上Validol产物进行了FT-TR、MS、13C NMR和1H NMR鉴别.最后,完成了反应温度、CO压力和薄荷醇、异丁烯浓度对羰基合成Validol反应速度的影响实验,提出了该反应的反应机理和催化循环过程.     

PVP-PdCl2-CuCl2/PPh3体系催化α-（6’-甲氧基-2’-萘基）乙醇羰化反应研究

首次用高分子负载型双金属催化剂PVP-PdCl2-CuCl2/PPh3体系催化α-（6’-甲氧基-2’-萘基）乙醇与一氧化碳及甲醇进行羰化反应制备萘普生甲酯, 分别对温度、压力、时间、 P/Pd比等影响因素进行了考察, 在反应条件为100 ℃、 16～20 h、 CO压力 4.0 MPa、 P/Pd=3时, 转化率可达97.4%, 异正比为14.4. 在同样条件下制备萘普生乙酯及萘普生异丙酯, 转化率及选择性均有明显下降. 另外, 该催化剂体系也可催化其它类型α-芳基乙醇的羰化反应.     

CO_2加氢制甲醇用高活性和高选择性催化剂的研制

研制了一种CO2加氢制甲醇用高活性和高选择性催化剂Cu-ZnO-Al2O3(简记为RK-11),测定了其催化性能.结果表明,当原料气组成(体积分数)为68.5%H2、2.0%CO、20.5%CO2、9.0%N2,温度为240℃,气体时空速度GHSV=6 000h-1,压力为8.0MPa时,CO2转化率达35.2%,CO转化率达39.8%,甲醇的时空产率达686.1g/(L·h),而甲醇在产物中的选择性达99.3%.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.