(E)-2,3-二溴-2-丁烯-1,4-二醇的合成

在2-丁炔-1,4-二醇与溴的加成反应体系中,添加适量的溴化钠,不但可以有效地提高(E)-2,3-二溴-2-丁烯-1,4-二醇的收率,而且反应可以在室温下进行,避免了低温冷却,更有利于工业化的生产。     

The Hydrogenation of 2-butyne-1,4-diol over a Carbon-supported Palladium Catalyst

The hydrogenation of 2-butyne-1,4-diol in propan-2-ol over a carbon-supported palladium catalyst has been investigated in a batch reactor. At low conversions complete selectivity to cis-but-2-ene-1,4-diol is observed. However, further hydrogenation leads to a wide variety of products, most notably 2-isopropoxy-tetrahydrofuran and butane, neither of which have previously been associated with this reaction system. The former is thought to occur as a result of a surface-mediated process, involving the insertion of dissociatively adsorbed solvent molecules. Butane formation is attributed to the double condensation and hydrogenation of a chemisorbed cis-but-2-ene-1,4-diol intermediate. The alkane preferentially partitions in the gaseous phase, which results in an marked mass imbalance for the liquid phase. A reaction scheme is presented to rationalise these observations.     

2-丁炔-1，4-二醇双对甲苯磺酸酯的合成工艺研究

以25％氢氧化钠为缚酸剂、以2-丁炔-1,4-二醇和对甲苯磺酰氟为原料,经磺酯化反应合成了2-丁炔-1,4-二醇双对甲苯磺酸酯。在n（对甲苯磺酰氯）：”（Na0H）;n（2-丁炔-1,4-二醇）为2．6：2．4：1、反应温度为0℃、反应时间为6h的最佳反应条件下,2-丁炔-1,4-二醇双对甲苯磺酸酯的收率迭94．1％。通过元素分析、IR以及1 HNMR对产物结构进行了表征。     

Zinc electrowinning with 2-butyne-1,4-diol

The beneficial effect of 2-butyne-1,4-diol on zinc current efficiency in the presence of nickel impurity has been examined. Several techniques including HPLC, absorption spectrophotometry and constant current deposition experiments have shown that a trimer of 2-butyne-1,4-diol is responsible for the removal of Ni ions from the electrolyte, thus increasing the current efficiency of the zinc electrowinning process from sulphate solutions (60 g/L Zn + 200 g/L H₂SO₄) in the presence of Ni ions.     

酸性树脂催化1,4-丁烯二醇制备2,5-二氢呋喃

提出1,4-丁烯二醇在酸性条件下脱水关环制备2,5-二氢呋喃的反应机理。实验对照了磺酸基树脂D61、D72以及膦酸基树脂LSC-500的催化性能,在5小时的反应过程中,它们的催化活性均逐渐下降,其中D61活性最强,平均每克催化剂1小时转化2.96克1,4-丁烯二醇,D61和D72的收率逐渐下降,LSC-500的收率最高而且比较稳定,保持在80%以上。     

Hydrogenation of 2-Butyn-1,4-diol in the Presence of Functional Crosslinked Resin Supported Pd Catalyst. The Role of Polymer Properties in Activity/Selectivity Pattern

Functional gel type resins of various crosslinking degrees (3–20%) with C=O and carboxylic groups were used as the supports for Pd catalysts (0.5–2 wt% Pd). The role of polymer properties was studied in the hydrogenation of 2-Butyne-1,4-diol (B3-D) to alkene (B2-D) and alkane (B1-D). Hydrogenation was studied at atmospheric pressure of hydrogen using THF, H₂O and THF + H₂O mixtures as the solvents. Systematic studies were carried out to determine the role of the type of solvent, crosslinking degree of polymer, the content of Pd in catalysts, initial B3-D concentration and the procedure of catalyst reduction in activity/selectivity behaviour of catalysts. Swelling degree of polymer matrix under the catalytic run exhibits crucial role in the activity and selectivity to alkene, B2-D. In the presence of highly expanded catalyst (THF solvent, 3% crosslinking degree, 1 wt% Pd) the alkyne, B3-D, is hydrogenated to alkene, B2-D, with selectivity ca. 85% up to high B3-D conversion (90%). The suppression of alkene to alkane hydrogenation in the stage of B3-D is ascribed to high ability of Pd centres in the Pd/OFP catalysts to strong adsorption of alkyne substrate. It may also be related to steric hindrances of polymer in the vicinity of active Pd centres. At small content of added water (5% by vol.) to THF the catalysts offer very attractive performance in terms of activity and 98% selectivity to alkene. Water facilitates interactions of B3-D with functional groups of polymer that leads to better expansion of polymer matrix and more effective suppression of alkene hydrogenation in the alkyne stage.     

Palladium nanoparticles stabilized in block-copolymer micelles for highly selective 2-butyne-1,4-diol partial hydrogenation

Pd nanoparticles (2 nm) stabilized in the micelle core of poly(ethylene oxide)-block-poly-2-vinylpyridine were studied in 2-butyne-1,4-diol partial hydrogenation. Both unsupported micelles (0.6 kg_Pd/m³) and supported ones on γ-Al₂O₃ (0.042 wt.% Pd) showed nearly 100% selectivity to 2-butene-1,4-diol up to 94% conversion. The only side product observed was 2-butane-1,4-diol. The catalysis was ascribed to Pd nanoparticles’ surface modified by pyridine units of micelles and alkali reaction medium (pH of 13.4). TOFs over the unsupported and supported catalysts were found to be 0.56 and 0.91 s⁻¹ (at 323 K, 0.6 MPa H₂ pressure, solvent 2-propanol/water = 7:3), respectively. Reaction kinetics fit the Langmuir–Hinshelwood model assuming weak hydrogen adsorption. The experiments on the catalyst reuse showed that Pd nanoparticles remain inside the micelle core, but the micelles slightly desorbed (less then 5%) during the catalytic run.     

Cis–trans isomerization of olefinic alcohols promoted by Rh(I) complexes

Homogeneous hydrogenation and isomerization reaction of cis-2-butene-1,4-diol has been investigated in ethanol by using tris(triphenylphosphine)chlororhodium(I), RhCl(PPh₃)₃, and triethylamine at 303 K and 0.01–0.1 MPa partial hydrogen pressure. Under reduced H₂ pressure, the geometric isomerization reaction occurs, to a high extent, leading to trans-2-butene-1,4-diol up to 93% selectivity at 90% conversion of the cis analogous. Effects of H₂ partial pressure as well as triethylamine, added phosphine and olefin concentrations on the rate of reaction and on the products distribution were also investigated. The results obtained can be interpreted on the basis of a proposed mechanism in which RhH(PPh₃)₃ is the active species. The high selectivity towards cis-trans isomerization of cis-2-butene-1,4-diol is attributed to steric factors of the Rh(I) coordinated triphenylphosphine groups.     

Influence of alkali metal doping on selectivity behaviour of platinum catalysts for hydrogenation of 2-butyne-1,4-diol

Hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol (B₂D) and butane-1,4-diol (B₁D) using Pt catalysts doped with alkali metals was studied. These catalysts showed higher selectivity to the olefinic diol (B₂D) compared to that with monometallic platinum catalyst. Among various alkali metals, Cs-doped catalyst showed highest selectivity (>99%) to B₂D. The selectivity to B₂D increased (up to 99.9%) with increase in the concentration of Cs from 0.25% to 1%. The increase in the basic strength of alkali doped catalysts measured by CO₂-TPD, would be responsible for the increase in electron density of Pt hence, faster desorption and higher selectivity to the intermediate olefinic diol (B₂D). The reaction parameters, such as temperature, H₂ pressure and substrate concentration have strong influence on the catalyst activity but almost no effect on the selectivity to B₂D.     

1,4-二氯-2-丁炔的合成

1，4－二氯－2－丁炔是合成链状脂肪烃类化合物的中间体，按照3－氯－1－丙烯的合成方法，在吡啶的存在下，2－丁炔－1，4－二醇与PCl3作用合成，采用CH2C2溶剂稀释反应物浓度，反应温度低，产物和溶剂均比水重，分离效率高，加入少量的相转移催化剂HMPA，反应收率可达72％。     

Effects of 2-buthyne-1,4-diol additive on electrodeposited Ni films from a Watts-type bath

Structures of Ni films electrodeposited from a Watts-type bath containing 2-buthyne-1,4-diol (BD) were investigated using SEM, cross-sectional SIM, XRD measurement with a pole profiling technique and electrochemical methods for controlling properties of Ni electrodeposits. Preferred orientation of Ni electrodeposits was assigned to potential domains for electrodeposition. Preferred orientation in the higher potential region was (1 1 0) or (1 0 0), that in the middle potential region were (1 1 1) and (3 1 1), and that in the lower potential region was (1 0 0). The growing axis of Ni electrodeposits seems to agree with the speculation from Pangarov's model based on the two-dimensional nuclei theory in the lower overpotential region in which the dominant growing plane is fundamentally determined by crystallization overpotential related to supersaturation of adatom, although the growth axes of Ni deposits do not always agree with the preferred orientation. For example, preferred orientation of (1 1 0) was assigned to growing (1 1 1) plane which tilts at 55° to the substrate. Adsorption of BD affects the structure and morphology of electrodeposits via an inhibitory effect related to its surface coverage depending on surface orientation, growth rate and BD concentration in the plating bath.     

Complexation of Titanium Alkoxides with Cis-2-butene-1,4-diol and Hydrolysis of Their Products

Reaction of Ti(OEt)₄ and Ti(OBu ⁿ )₄ with cis-2-butene-1,4-diol (B.diol-2H) in 1:1 molar ratio was studied at room temperature using the sol-gel process. ¹³C{¹H}- and ¹H-NMR data showed that all the B.diol-2H completely reacted with both titanium alkoxides. Each of the products was hydrolyzed by water. The new hydrolyzed products were characterized by ¹³C- and ¹H-NMR spectroscopy and Karl–Fischer Titration. Thermogravimetric and differential thermal analyses (TGA-DTA) of the hydrolyzed-products were also studied.     

2-苯基-1,3-丙二醇合成工艺的研究

以苯乙酸乙酯、甲酸乙酯、甲醇钠、硼氢化钠为原料合成标题化合物,该方法操作方便,总收率达80.1%,产品纯度高达99.5%.同时研究了溶剂对第二步还原反应的影响,研究表明,乙醇作溶剂时收率较高,成本较低.通过IR和 ~1HNMR 分析确定了目标化合物的结构.     

活性炭固载磷钨酸催化合成异丁醛缩顺—2—丁烯—1，4—二醇

研究了用活性炭固载磷钨酸催化合成异丁醛缩顺 -2 -丁烯 -1,4-二醇。考察了催化剂固载量、醇醛物质的量比、带水剂用量等因素对缩合反应的影响。其优化条件为 :顺 -2 -丁烯 -1,4-二醇、异丁醛、催化剂、带水剂的量分别为 1mol、1.0 5mol、7.0 g、10 0mL ,反应在回流温度下进行 ,时间约 3h ,收率达 86.4%。催化剂可重复使用     

The selective hydrogenation of butyne-1,4-diol by supported palladiums: a comparative study on slurry, fixed bed, and monolith downflow bubble column reactors

The present study was carried out to asses performance of a Pd-monolith downflow bubble column (DBC) reactor, and compare it with that of the slurry and the fixed bed DBC. The selective hydrogenation of butyne-1,4-diol to cis-2-butene-1,4-diol over palladium catalyst was chosen as a model reaction. In principle, the monolith DBC allowed the reaction to take place under kinetic control regime. Comparison with DBC employing 5% Pd/C powder and 1% Pd-on-Raschig ring catalysts revealed a better performance of the monolith DBC (1% Pd loading) with advantage of smaller reaction volume and intensified reaction rate. In the monolith DBC, improved hydrogen transport was possible, as the interface between bubbles and the channel wall was very thin, thus, the length of the diffusion path was very short. In addition, the interfacial surface area at both gas–liquid and liquid–solid interface in the monolith was also very high. The reaction kinetics was well represented by the Langmuir–Hinshelwood mechanism. As an alternative to conventional three-phase reactors, the monolith DBC was simple due to its inherent characteristic operation and no specially designed device.     

两类聚酯吸氧材料的制备及性能

制备了1,4-丁烯二醇/顺丁烯二酸酐和端羟基聚丁二烯（HTPB）/顺丁烯二酸酐酯化物吸氧剂,讨论了反应时间及醇酐比对吸氧剂酯化率的影响,并且将1,4-丁烯二醇/顺酐、HTPB/顺酐吸氧剂接枝共聚到PET中得到改性吸氧材料。考察了两种吸氧材料的物理性能和吸氧性能,以及影响吸氧性能的双键保留率,催化剂用量、醇酐比。实验表明,顺酐与1,4-丁烯二醇、HTPB反应的最佳酯化时间分别为2 h和3 h,含1,4-丁烯二醇/顺酐和HTPB/顺酐的吸氧材料最大数均分子量分别为3.66万和4.97万,最大双键保留率分别为77.4%和76.3%,最大催化剂用量为1.0 g/kg,含1,4-丁烯二醇/顺酐和HTPB/顺酐的吸氧材料24 h最大吸氧量为3.17 mL/g和10.04mL/g。     

利用呋喃酚废渣制备4-异丁基-1,2-邻苯二酚

在Pd/C催化下,通过催化加氢,将呋喃酚废渣中的4-(2-甲基烯丙基)-1,2-苯二酚,经精馏分离纯化得4-异丁基-1,2-苯二酚。产品纯度主要组分达98%,反应收率91%。     

1,4-二氯-2-丁炔的合成

不饱和二氯烷烃在有机合成中有着广泛的应用,通常由相应的不饱和醇制备。由2-丁炔-1,4-二醇可以很方便地得到1,4-二氯-2-丁炔,将2-丁炔-1,4-二醇(固体)的N,N-二甲基甲酰胺(DMF)溶液滴加到二氯亚砜中,在冰水浴中反应生成1,4-二氯-2-丁炔,产率可达到87.4%。上述制备方法反应条件温和、操作和装置简单。     

混酸催化1,4-桉叶素异构化合成4-松油醇的研究

研究了在磷酸和乙酸混酸催化下,1,4-桉叶素异构化合成4-松油醇。考察了混酸催化剂种类、催化剂用量、反应温度、反应时间等因素对反应的影响。结果表明,最佳反应条件为:1,4-桉叶素10 mL,在12 mL磷酸与乙酸体积比为6∶1的混合酸催化剂中,反应温度60℃,反应时间8 h,1,4-桉叶素转化率可达74.66%,选择性为75.4%。精制后的4-松油醇质量分数在90%以上。     

Preparation and study of terephthalate copolyester of ethylene glycol and butane-1,4-diol

Summary Random terephthalate copolyesters of ethylene glycol and butane-1,4-diol of various compositions were prepared by trans-esterification of poly(ethylene terephthalate) (PET) with butane-1,4-diol (BD). Proton nuclear magnetic resonance spectroscopy (NMR) was used to elucidate the structure and compositions of copolyesters. The thermal behaviour of the copolyesters were investigated by differential thermal analysis (DTA). Intrinsic viscosities were measured in orthochlorophenol at 30°C.