双二茂铁基醛亚胺钼（ＶＩ）配合物的合成及催化性能

通过二茂铁甲醛与丙二胺反应得到双二茂铁基醛亚胺配体N~1,N~3-双二茂铁亚甲基丙烷-1, 3-二胺(FcMP), FcMP与MoO_2Cl_2(THF)_2的四氢呋喃溶液作用, 合成了双二茂铁基醛亚胺钼(VI)配合物. 以配合物为催化剂, 叔丁基过氧化氢为氧化剂, 分别以苯乙烯和环己烯为底物, 考察了温度、时间、催化剂量及溶剂对于烯烃均相环氧化反应的催化性能的影响. 结果表明, 在最优实验条件下, 反应12 h, 环己烯的转化率为88%, 环氧环己烷的选择性为98%;苯乙烯的转化率为84%, 氧化苯乙烯的选择性为76%. 催化剂经简单分离可回收使用, 且催化活性基本保持不变. 同时对环氧化反应的机理进行了初步探讨.     

CuCl/菲咯啉/甲基咪唑催化甲醇/乙醇氧化羰化一步合成碳酸甲乙酯

 研究了CuCl与含氮杂环化合物配体1, 10-菲咯啉(phen)和N-甲基咪唑(NMI)形成的配合物催化剂对甲醇/乙醇氧化羰化一步合成碳酸甲乙酯(MEC)反应的催化活性. 讨论了配体的配比、甲醇和乙醇的相对用量、温度及压力等因素对甲醇和乙醇的转化率及MEC产率的影响. 结果表明,CuCl/phen/NMI原位配合物催化剂对氧化羰化一步合成MEC反应具有较高的催化活性. 配体phen及NMI对反应产物的选择性有明显的调变作用,甲醇和乙醇的配比对产物分布有很大的影响. 在V(MeOH)/V(EtOH)=0.25,c(CuCl)=0.20 mol/L,n(CuCl)∶n(NMI)∶n(phen)=1∶1.25∶1.25,p=2.40 MPa,θ=120 ℃的条件下反应2 h,甲醇的转化率为44.3%,乙醇的转化率为22.3%,MEC的产率为10.4%.     

温控相分离纳米Rh催化1,5-环辛二烯选择性加氢反应

发现离子液体[CH3(OCH2CH2)nN+Et3][CH3SO3-](ILPEG,n=12,16,22)具有临界溶解温度特性,据此确证了以ILPEG为稳定剂制得的Rh纳米催化剂具有温控相分离催化功能,并将其用于1,5-环辛二烯(1,5-COD)选择性加氢制环辛烯(COE)的反应中.在优化的反应条件下,1,5-COD转化率和COE选择性分别为99%和90%;Rh纳米催化剂经简单分相即可与产物分离,催化剂循环使用10次,其活性和选择性无明显降低.     

钯催化 1,3-丁二烯羧酯化合成 3-戊烯酸甲酯

 以 1,3-丁二烯、CO 和甲醇为原料, 进行羧酯化反应合成 3-戊烯酸甲酯是 Altam 路线生产己内酰胺绿色工艺的关键步骤. 将 Pd 与三齿 N-杂环配体或双膦配体组成的催化体系用于 1,3-丁二烯的羧酯化反应中, 其中乙酸钯/2,6-二 (3,5-二甲基吡唑基) 吡啶催化剂表现出中等的催化活性, 在 150 ºC, p(CO) = 6.0 MPa 的优化条件下反应 6 h, 1,3-丁二烯转化率为 78.8%, 3-戊烯酸甲酯选择性达 92.2% (TON = 226); 而乙酸钯/2,2?-二 (二苯基膦基) 苯醚催化体系的活性更高, 在优化反应条件下, 1,3-丁二烯转化率达 90.4%, 3-戊烯酸甲酯选择性为 91.6% (TON = 181). 在 200 ºC 及类似的羧酯化反应条件下, 1,3-丁二烯发生二聚反应, 其转化率为 99% 以上, 二聚产物 4-乙烯基-1-环己烯选择性高于 96%.     

氮杂冠醚取代非对称双Schiff碱配合物催化氧化对二甲苯研究

将一系列苯并-10-氮杂-15-冠-5或吗啉基取代的不对称双Schiff碱配合物作为催化剂,在常压和120℃条件下用于催化氧化对二甲苯研究。探讨了Schiff配合物中心金属离子、Schiff碱配体中挂接的氮杂冠醚环、配体芳环上取代基等对催化氧化对二甲苯反应活性及其氧化产物选择性的影响。实验结果表明:配合物中氮杂冠醚的存在能显著缩短反应诱导期、提高催化活性和选择性;Schiff碱Mn(Ⅲ)配合物比Schiff碱Co(Ⅱ)和Schiff碱Cu(Ⅱ)具有更高的催化活性;氮杂冠醚Schiff碱Mn(Ⅲ)配合物催化氧化二甲苯的转化率和产物选择性分别达75%和90%。     

水溶性钌-氢配合物催化1-已烯双键异构化反应研究

研究了水溶性钌-氢配合物RuHCl(TPPTS)3在水/有机两相体系中催化1-己烯双键异构化反应.考察了反应温度、时间、膦配体浓度、相转移催化剂CTAB浓度以及底物与催化剂摩尔比等对转化率和产物选择性的影响.在最佳条件下1-己烯转化率达到82.4%,2-己烯选择性21.2%,3-己烯61.2%,没有发现骨架异构化.催化剂可重复使用5次.     

聚氧乙烯基取代膦—铑配合物催化有机单相苯乙烯氢甲酰化反应研究

基于非离子表面活性膦配体的临界溶解温度特性 ,研究了以 Rh Cl3· 3H2 O为催化剂前体、聚氧乙烯基取代膦为配体原位合成的膦铑配合物催化剂 ,对有机单相体系中苯乙烯氢甲酰化反应的催化性能 .考察了反应温度、压力及不同聚氧乙烯基取代膦 -铑配合物催化剂对反应的影响 .以 Rh/PETPP配合物为催化剂时 ,在 T=10 0℃ ,p=6 .0 MPa (CO/H2 =1∶ 1)条件下 ,反应 3.5 h后 ,烯烃转化率和产物醛收率可分别达 96 .7%和 92 .6 %     

钛酸酯催化碳酸二甲酯与苯酚酯交换反应的研究

用Ti(OBu)4、Ti[OCH(CH3)2]4和T(OPh)43种钛酸酯作催化剂,对碳酸二甲酯（DMC）与苯酯的酯交换反应进行了研究。以Ti(OBu)4为催化剂,对反应的热力学、原料配比、催化剂用量、反应温度和反应时间等工艺条件进行了考察 。实验表明,当DMC：苯酚：Ti(OBu)4(摩尔比）＝1.5:1:0.05、反应温度175℃、反应时间为25h时,酯交换反应基本上达到平衡,苯酚的转化率为47.4％,MPC的选择性为90.9%,DPC的选择性为9.14%.     

超临界二氧化碳中功能化聚乙二醇稳定的钯纳米粒子催化醇的选择氧化反应

 以超临界二氧化碳 (scCO2)/聚乙二醇 (PEG) 两相为反应介质, 双齿氮配体功能化聚乙二醇稳定的 Pd 纳米颗粒作为催化剂, 进行了醇的需氧氧化反应. 系统研究了催化剂制备条件和反应条件对苯甲醇需氧氧化反应的影响. 结果表明, 以氢气为还原剂制备的 Pd 纳米粒子的催化活性最高. 反应结束后, 可以利用 scCO2 直接进行原位萃取得到产物, 实现了催化剂与产物的有效分离和催化剂的循环使用. 反应中没有检测到钯的流失. 催化剂经过 5 次循环利用后转化率仍可达 98%.     

羟胺酸钴配合物催化对二甲苯氧化的研究

利用羟胺酸BPHA(N 苯甲酰基 N 苯基羟胺)钴配合物Co(BPHA)2作催化剂,对对二甲苯液相氧化反应进行了研究.详细考察了反应温度、催化剂浓度、配体浓度、反应时间和轴配体对该催化反应的影响.实验结果表明:当反应温度为125℃、氧气压力为0.5MPa、催化剂浓度为1.0×10-3mol/L、配体与催化剂的摩尔比为2∶1时、添加四甘醇或聚乙二醇作配体,反应2h时对二甲苯转化率可达41～43%、选择性为92%.本研究丰富了二甲苯选择性氧化的内容,并具有一定的工业应用前景.     

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%.     

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.     

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.