钯催化的酰胺羰基化反应合成草铵膦

[目的]研究采用钯催化的酰胺羰基化反应制备草铵膦。[方法]以(3,3-二乙酰氧基)丙基甲基次膦酸异丁酯为初始原料,经酸解得到3-甲基异丁氧基膦酰基丙醛,然后经过钯催化的酰胺羰基化反应得到2-乙酰氨-4-甲基(异丁氧基)膦丁酸,最后经水解、氨化制得草铵膦,并对反应条件进行优化。[结果]3-甲基异丁氧基膦酰基丙醛的收率达到80%,草铵膦的收率可达50%。[结论]钯催化的酰胺羰基化反应为合成草铵膦提供了新的方法,避免了传统工艺中氰化物的使用,减少了三废。     

异丁烯氢甲酰化合成异戊醛的研究

以Rh(acac)(CO)_2/双亚磷酸酯体系为催化剂,提高异丁烯氢甲酰化反应的活性和选择性。在此基础上考察了温度、压力、溶剂、有机碱、催化剂套用等参数对异丁烯氢甲酰化反应的影响。结果表明,以Rh(acac)(CO)_2/双(2,4-二叔丁基苯基)季戊四醇二亚磷酸酯为催化体系,铑的溶液浓度为1.55×10~(-3)mol/L,异戊醛为溶剂,三苯基氧膦为有机碱,在110℃下2 MPa的合成气下反应6 h,异丁烯的转化率高达96.82%,选择性为99.75%,套用4次衰减很小。该催化剂体系显著提高了异丁烯氢甲酰化反应的活性和选择性,且具有良好的套用性能。     

异丁烯氢甲酰化合成异戊醛的研究

以Rh(acac)(CO)_2/双亚磷酸酯体系为催化剂,提高异丁烯氢甲酰化反应的活性和选择性。在此基础上考察了温度、压力、溶剂、有机碱、催化剂套用等参数对异丁烯氢甲酰化反应的影响。结果表明,以Rh(acac)(CO)_2/双(2,4-二叔丁基苯基)季戊四醇二亚磷酸酯为催化体系,铑的溶液浓度为1.55×10^(-3)mol/L,异戊醛为溶剂,三苯基氧膦为有机碱,在110℃下2 MPa的合成气下反应6 h,异丁烯的转化率高达96.82%,选择性为99.75%,套用4次衰减很小。该催化剂体系显著提高了异丁烯氢甲酰化反应的活性和选择性,且具有良好的套用性能。     

环氧乙烷羰基合成1,3-丙二醇研究进展

综述了近年来环氧乙烷羰基化法合成1,3-丙二醇的研究进展,介绍了氢甲酰化法和氢酯基化法2条工艺路线及其金属催化体系,认为以环氧乙烷羰基化法为发展重点,进一步开发新型双金属非膦配体高活性低成本催化体系对我国未来1,3-丙二醇的工业应用具有现实意义。     

9-(2-羟基乙基)-6-氨基-2-烷硫基嘌呤衍生物的合成

以2-氨基-6-氯嘌呤为原料,与2-溴乙基乙酸酯反应得到9-乙酰氧基乙基-2-氨基-6-氯嘌呤(Ⅰ),收率65.6%;Ⅰ经重氮-烷硫化得到9-乙酰氧基乙基-2-烷硫基-6-氯嘌呤(Ⅱ),收率58.3%~72.1%;Ⅱ与叠氮化钠反应得到9-乙酰氧基乙基-2-烷硫基-6-叠氮嘌呤(Ⅲ),收率86.4%~92.0%。经核磁检测Ⅲ在溶液中存在叠氮结构(A)和四氮唑结构(T)的互变异构现象,CDCl3中叠氮结构比例在61.5%~67.2%。采用PPh3-HCl-DMSO为反应体系,"一锅法"将叠氮基还原为氨基同时将酯基彻底水解,高收率(~90%)得到9-(2-羟基乙基)-6-氨基-2-烷硫基嘌呤衍生物(Ⅳ)。这些化合物的结构经IR、1HNMR、13CNMR及HRMS得到确证。     

新的手性膦配体的合成及其在苯乙烯不对称氢甲酰化反应中的应用

以甘露醇为原料合成了两个新的手性膦配体，并用这些新的手性膦配体和醋酸钯原位生成的催化剂体系催化苯乙烯的不对称氢甲酰化反应，当配体为手性膦氧配体(DDPPIO)时得到S构型的2-苯基丙醛的e.e.为21.9％，用手性膦硫配体(DDPPIS)作配体时得到S构型的2-苯基丙醛的e.e.11.2％。     

(R)-(-)-3-氯-1,2-丙二醇合成(S)-(+)-缩水甘油对甲苯磺酸酯的研究

以环氧氯丙烷动力学水解制备(S)-环氧氯丙烷过程中所产生的水解副产物为原料合成医药中间体(S)-( )-缩水甘油对甲苯磺酸酯.环氧氯丙烷动力学水解制备(S)-环氧氯丙烷过程中所产生的水解副产物经过精密分馏得到(R)-(-)-3-氯-1,2-丙二醇,然后经脱HCl环化得到(S)-( )-缩水甘油,再进一步与对甲苯磺酰氯反应得到(S)-( )-缩水甘油对甲苯磺酸酯.在适宜合成条件下其得率为73%.     

官能团化烯烃的氢甲酰化反应研究及应用进展

氢甲酰化反应已发展成为重要的工业均相催化反应之一,通过官能团化烯烃氢甲酰化反应可以得到官能团化的醛类化合物,该类化合物大多是精细化学品或合成中间体,官能团化烯烃显示出很多不一样的特性。综述近年来官能团化烯烃氢甲酰化反应研究进展,介绍乙烯基芳烃、α-官能团化烯烃以及β-官能团化烯烃的氢甲酰化反应及应用,并对官能团化烯烃氢甲酰化反应进行展望。     

固体酸催化合成3,5-二乙酰氧基苯乙烯

以3,5二-羟基苯乙酮(4)为原料,经三步反应制得3,5二-乙酰氧基苯乙烯(1)。在硫酸催化下化合物(4)与乙酸酐反应,得到3,5二-乙酰氧基苯乙酮(3),收率92%,对于化合物(3)进行了1H NMR表征;化合物(3)经催化加氢,得到1-(1羟-基乙基)-3,5二-乙酰氧基苯(2),收率98%,对于化合物(2)进行了1H NMR表征;化合物(2)在固体酸催化下反应得到3,5二-乙酰氧基苯乙烯(1),制备化合物(1)的反应条件为:m[化合物(2)]∶m(固体酸)=5∶1,110℃回流5 h,收率95%,纯度98%,对化合物(1)进行了IR,1H NMR,MS表征,并对化合物(1)的1HNMR,MS表征结果进行了进一步分析。     

含功能团烯烃氢甲酰化的研究

0 引言α-碳烯烃氢甲酰化是制备醛醇化合物重要的过程和人们广泛研究的领域。含功能团烯烃(如酯、腈、醇、醚等)氢甲酰化更具有合成意义和工业价值,越来越引起人们的重视。如丙烯腈在 Co_2(CO)_8 催化剂作用下局部选择氢甲酰化,以80%产率生成3-氰基丙醛,用于制备左旋谷氨酸钠盐。     

Various approaches to transfers improvement during biphasic catalytic hydroformylation of heavy alkenes

The [HRh(CO)(TPPTS)₃] precursor, where TPPTS is the water-soluble P(m-C₆H₄SO₃Na)₃ ligand, has opened a large area for the Supported-Aqueous-Phase (SAP) catalysed functionalisation of heavy substrates. We investigated several ways to increase the efficiency of heavy alkenes hydroformylation by [Rh₂(μ-S^tBu)₂(CO)₂(TPPTS)₂]. Addition of a cosolvent was shown to lead to a significant leaching of rhodium in the organic phase. Promising results were obtained. First, the Delmas–Chaudhari method of adding small amounts of PPh₃ to [HRh(CO)(TPPTS)₃] to maintain the complex at the interface, was examined for [Rh₂(μ-S^tBu)₂(CO)₂(TPPTS)₂]. Here [Rh₂(μ-S^tBu)₂(CO)₂(PPh₃)₂] was rapidly formed and is operating classically in the organic phase. Moreover, β-cyclodextrin was used as a phase-transfer agent allowing the inclusion of the substrate and its transport to the aqueous phase where the reaction is occurring. Finally, the use of silica with various hydration ratios in SAP catalysis led us to propose that the microreactors containing water, complex and extra TPPTS operate on the surface of the support.     

Supercritical carbon dioxide as an alternative reaction medium for hydroformylation with integrated catalyst recycling

The cobalt-catalyzed hydroformylation of 1-octene using the complex bis{tri(3-fluorophenyl)phosphine}hexacarbonyldicobalt (1) and Co₂(CO)₈ as pre-catalysts in supercritical carbon dioxide (scCO₂) as a reaction medium was investigated. The catalytic performance in scCO₂ was compared to the one in toluene as a conventional solvent. Similar activities and selectivities were obtained in both reaction media. In scCO₂, a substantial improvement of the selectivity for aldehydes was found by using (1) (P:Co = 1:1) in comparison to the unmodified catalyst Co₂(CO)₈ (P:Co = 0:1). Surprisingly, further addition of (m-FC₆H₄)₃P (P:Co = 6:1 and 11:1, respectively) resulted in a little enhancement of the aldehydes selectivity only, whereas the conversion and, hence, the aldehydes yield were reduced. A concept for catalyst recycling by using scCO₂ was introduced. It was found that (1) was insoluble in the cold reaction mixture and was completely soluble in the supercritical reaction medium. By cooling the reactor content after the olefin conversion, the catalyst was regenerated as a solid, separated by filtration and could be recycled several times.     

Al_2(SO_4)_3/FeCl_3催化合成乙酸异戊酯

以冰乙酸和异戊醇为原料,Al_2(SO_4)_3/FeCl_3为催化剂,对催化合成乙酸异戊酯的条件进行研究。考察催化剂用量、乙酸与异戊醇物质的量比以及反应时间对乙酸酯化率的影响。结果表明,Al_2(SO_4)_3/FeCl_3具有良好的催化活性,在乙酸物质的量为0.1 mol、乙酸与异戊醇物质的量比为1∶4、催化剂用量1.0 g、反应时间2.0 h和带水剂环己烷用量10 m L反应条件下,重复实验3次,平均乙酸酯化率为93.50%。     

Ethylene hydroformylation and carbon monoxide hydrogenation over modified and unmodified silica supported rhodium catalysts

Ethylene hydroformylation and carbon monoxide hydrogenation (leading to methanol and C₂-oxygenates) over Rh/SiO₂ catalysts share several important common mechanistic features, namely, CO insertion and metal–carbon (acyl or alkyl) bond hydrogenation. However, these processes are differentiated in that the CO hydrogenation also requires an initial CO dissociation before catalysis can proceed. In this study, the catalytic response to changes in particle size and to the addition of metal additives was studied to elucidate the differences in the two processes. In the hydroformylation process, both hydroformylation and hydrogenation of ethylene occurred concurrently. The desirable hydroformylation was enhanced over fine Rh particles with maximum activity observed at a particle diameter of 3.5 nm and hydrogenation was favored over large particles. CO hydrogenation was favored by larger particles. These results suggest that hydroformylation occurs at the edge and corner Rh sites, but that the key step in CO hydrogenation is different from that in hydroformylation and occurs on the surface. The addition of group II–VIII metal oxides, such as MoO₃, Sc₂O₃, TiO₂, V₂O₅, and Mn₂O₃, which are expected to enhance CO dissociation, leads to increased rates in CO hydrogenation, but only served to slow the hydroformylation process slightly without any effect on the selectivity. Similar comparisons using basic metals, such as the alkali and alkaline earths, which should enhance selectivity for insertion of CO over hydrogenation, increased the selectivity for the hydroformylation over hydrogenation as expected, although catalytic activity was reduced. Similarly, the selectivity toward organic oxygenates (a reflection of the degree of CO insertion) in CO hydrogenation was also increased.     

The influence of different monodentate P-ligand mixtures on Rh-catalyzed 1-butene hydroformylation

Four monodentate P-ligands and their mixtures (six groups of double-ligand systems, four groups of triple-ligand systems and one group of tetra-ligand system) were used with Rh(acac)(CO)₂ (acac=acetylacetonate) or Rh (acac)CO(PPh₃) as the catalyst in the hydroformylation reaction of 1-butene. It was found that different Rh catalysts showed little difference in the catalysis performance. The general order of catalysis performance is doubleligand system > single-ligand system > triple-ligand system > tetra-ligand system. Some synergistic effect in the double-ligand system was detected which needs a further investigation.     

Graft polymerization of vinyl monomers from initiating groups introduced onto polymethylsiloxane-coated titanium dioxide modified with alcoholic hydroxyl groups

The grafting of vinyl polymers onto the surface of polymethylsiloxane-coated titanium dioxide modified with alcoholic hydroxyl groups (Ti/Si–R–OH) were investigated. The introduction of azo and trichloroacetyl groups onto the surface of Ti/Si–R–OH was achieved by the reaction of the surface alcoholic hydroxyl groups with 4,4′-azobis(4-cyanopentanoic acid) and trichloroacetyl isocyanate, respectively. The radical polymerizations of vinyl monomers were successfully initiated by the azo groups introduced onto the surface and by the system consisting of Mo(CO)₆ and Ti/Si–R–COCCl₃. During the polymerization, the corresponding polymers were effectively grafted onto the titanium dioxide surface through propagation from surface radicals formed by the decomposition of azo groups and by the reaction of Mo(CO)₆ with trichloroacetyl groups on the surface. The percentage of grafting and grafting efficiency in the graft polymerization initiated by the system consisting of Ti/Si–R–COCCl₃ and Mo(CO)₆ were much larger than those initiated by azo groups. The polymer-grafted titanium dioxide was found to produce a stable colloidal dispersion in good solvents for the grafted polymer. The dispersibility of poly(N,N-diethylacrylamide)-grafted titanium dioxide in water was controlled by temperature. In addition, the wettability of the surface of titanium dioxide to water was readily controlled by grafting of hydrophilic or hydrophobic polymers.     

Heterogenized HRh(CO)(PPh3)3 on zeolite Y using phosphotungstic acid as tethering agent: a novel hydroformylation catalyst

Heterogenization of HRh(CO)(PPh₃)₃ tethered through phosphotungstic acid to zeolite Y support, gives a novel hydroformylation catalyst with excellent stability, reusability and even improved activity. The activity, selectivity and stability of this catalyst for hydroformylation of a variety of linear and branched olefinic substrates have been demonstrated. The heterogenized HRh(CO)(PPh₃)₃ catalyst was recycled several times without loss of any activity. The catalyst was characterized by powder XRD, SEM, XPS, and ³¹P CP MAS NMR to establish true heterogeneity and morphological characteristics.     

氢气高温还原制备的负载型镍基催化剂用于苯酚加氢的性能

通过等体积浸渍法分别将Ni(NO₃)₂、NiCl₂、NiSO₄ 3种镍前体浸渍于A1₂O₃或SiO₂载体上,然后通过H₂高温还原法制备了负载型镍基催化剂,考察了镍前体、载体种类、镍负载量、反应条件等对镍基催化剂苯酚加氢性能的影响。结果表明,对比3种镍前体,在H₂高温还原体系中Ni(NO₃)₂最容易被还原,制备的镍基催化剂苯酚加氢活性最高。SiO₂负载的镍基催化剂活性远高于γ-Al₂O₃催化剂。适宜的Ni负载量有助于活性组分的分散和催化活性的提高。镍基催化剂的苯酚加氢产物以环己醇为主,相对缓和的反应条件更容易生成环己酮。在非极性溶剂正庚烷或环己烷存在下,苯酚加氢反应速率远远高于极性溶剂水或乙醇存在下的结果,而且环己酮的选择性更高。     

Towards recycling purpose: Converting PET plastic waste back to terephthalic acid using pH-responsive phase transfer catalyst

Converting polyethylene terephthalate (PET) wastes to its monomer and valuable chemicals via eco-friendly chemical method is still a challenge task. Previously, phase transfer catalysts used for alkaline hydrolysis were soluble in reaction media and hardly separated after reaction. Here, we reported several pH-responsive catalysts combined alkyl quaternary ammonium units with heteropolyacid anion for achieving stepwise product/catalyst separation and catalyst recycling. The properties of homogeneous/heterogeneous transfer behavior allow catalyst to be easily separated from reaction media by adjusting of pH value. Among them, [C₁₆H₃₃N(CH₃)₃]₃PW₁₂O₄₀ (abbreviated as [CTA]₃PW) exhibits the highest activity and the most suitable pH responsive values. Such a pH triggered switchable catalytic system not only shows good performance for depolymerization of pure PET, but also some real PET wastes such as coloured trays and PE/PET complex films could be completely degraded into terephthalic acid. Additionally, the reaction kinetics and activation energy of PET alkaline hydrolysis also studied with and without pH-responsive [CTA]₃PW.     

CHEMICAL AND TECHNICAL ASPECTS OF HYDROFORMYLATION OF OLEFINS WITH SUPPORTED LIQUID-PHASE RHODIUM CATALYSTS

Supported liquid-phase catalysts containing RhH(CO)(PPH₃)₃ dissolved in PPH₃ are used in the gas-phase hydroformylation of several olefins. Their activity in the hydroformylation of ethylene, propylene and the butenes is reported.

Various physicochemical aspects of the rhodium SLP catalysts, such as the adsorptive withdrawal of the rhodium complexes by the supports, the activity of the rhodium complexes at the gas-liquid interface and the solubility of the reactants and products in the liquid part of the catalysts, are discussed.

The results are presented of a bench-scale process study of the hydroformylation of propylene, from which the design parameters of a future plant are calculated.