1,4-丁炔二醇加氢制1,4-丁烯二醇工艺及催化剂研究进展

论述1,4-丁烯二醇发展现状,简述1,4-丁烯二醇BYD加氢法、3,4-环氧-1-丁烯水解法和1,3-丁二烯法3种生产工艺特点.其中,BYD催化加氢法是生产BED技术最为成熟、应用最为广泛的生产工艺.BYD加氢反应是一个多步复杂反应.论述了BYD加氢催化反应过程以及3种催化剂(贵金属催化剂、过渡金属催化剂、骨架型Ran...     

电化学合成2,5-二甲氧基-2,5-二氢呋喃甲醇工艺研究

以糠醇为原料,NaBr为电解质,甲醇为溶剂,利用电化学法合成焦袂康酸中间体2,5-二甲氧基-2,5-二氢呋喃甲醇,考察反应时间、NaBr添加量、反应温度对产率的影响。结果表明,反应时间与反应温度对产率有显著影响,NaBr添加量对产率影响不显著。当加入糠醇3 g(24 mmol),恒压15 V,最优条件为反应时间2.4 h, NaBr添加量为1.76 g,反应温度-10℃时,平均电流0.93 A,2,5-二甲氧基-2,5-二氢呋喃甲醇产率为67.9%。     

催化半氢化制备1,4-丁烯二醇

研究制备了聚－γ－氨丙基硅氧烷钯络合物催化剂ＰＣＡＬ，用于丁炔二醇（ＢＹ）的催化半氢化，半氢化产物丁烯二醇（ＢＥ）收率高达９５％。在相同试验条件下用Ｌｉｎｄｌａｒ催化剂作了催化半氢化丁炔二醇的对比，发现二者有相同的催化效果，就生成ＢＥ的选择性和催化剂寿命而言，ＰＣＡＬ催化剂具有更多优点。该催化剂是适用于炔醇催化半氢化的新品种催化剂。     

毛细管气相色谱法测定2,5-二氢呋喃含量

目的:建立气相色谱法测定2,5-二氢呋喃含量。方法:采用DB-624石英毛细管柱(30 m×0.53 mm×3μm),以乙腈为内标物,检测器:氢火焰离子化检测器,柱温:程序升温,初始温度45℃,保持5 min,以10℃/min升至250℃,保持10 min。进样器温度:220℃;检测器温度280℃;载气:氮气,流速3 mL/min,分流比:30∶1。结果:2,5-二氢呋喃在5.884~29.422 mg·mL~(-1)范围内与峰面积呈良好的线性关系,r=0.999 95;平均回收率(n=5)为100.03%。结论:本法灵敏度高、结果准确、重复性好,可用于2,5-二氢呋喃的质量控制。     

(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。     

1,4-丁二醇选择性催化脱水制备3-丁烯-1-醇的工艺技术

探讨了1,4-丁二醇选择性催化脱水制备3-丁烯-1-醇的工艺技术。探讨了焙烧温度、金属氧化物掺杂,以及气液比、反应温度对反应工艺的影响,并分析了催化剂的性能表征。结果显示：在CaO-ZrO₂类催化剂中掺杂SnO₂和Bi₂O₃,可提升1,4-丁二醇转化率及3-丁烯-1-醇收率;反应温度与焙烧温度相同时,CaO-ZrO₂-SnO₂催化剂的催化性能更好;在380℃的反应温度下,CaO-ZrO₂-SnO₂作催化剂,1,4-丁二醇转化率及3-丁烯-1-醇收率达到最佳。研究结果对利用1,4-丁二醇选择性脱水制备3-丁烯-1-醇的工艺开发具有参考价值。     

钯催化2,5-二氢呋喃的氢胺羰基化反应

以氯化钯为催化剂,三苯基膦为配体,对甲苯磺酸为助催化剂,通过2,5-二氢呋喃与具有不同取代基的芳香胺、一氧化碳的氢胺羰基化反应,合成了一系列四氢呋喃-3-甲酰胺类化合物。用IR、1HNMR、13CNMR、HRMS对产物进行了结构表征。并考察了不同芳香胺底物的适应性,当苯胺上的取代基为烷基、卤素、甲氧基以及硝基时,均能得到四氢呋喃-3-甲酰胺类衍生物,收率为54.3%～93.2%。     

2-甲基-2,5-二甲氧基-2,5-二氢呋喃合成研究

2-甲基-2,5-二甲氧基-2,5=二氢呋喃是合成重要肉香味香料2-甲基-3-呋喃硫醇的原料,本文对其合成方法进行了研究,产率达到77.4％～87.0％。     

氯化亚铁催化合成呋喃-2,5-二甲酸及其二甲酯

以氯化亚铁为催化剂,呋喃、四氯化碳和甲醇回流反应10 h合成了呋喃-2,5-二甲酸二甲酯,产率97.5%;呋喃-2,5-二甲酸二甲酯经碱性条件下水解、酸化合成了呋喃-2,5-二甲酸,总产率90.7%。     

Palladium supported on filamentous active carbon as effective catalyst for liquid-phase hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol

Structured palladium catalysts suitable for three-phase reactions have been developed based on woven fabrics of active carbon fibres (ACF) as the catalytic supports. The Pd/ACF were tested in liquid-phase hydrogenation of 2-butyne-1,4-diol showing a selectivity towards 2-butene-1,4-diol up to 97% at conversions up to 80%. The catalyst multiple reuse with stable activity/selectivity in a batch reactor was also demonstrated. The reaction kinetics was studied and the main kinetic parameters were obtained. Assuming a Langmuir-Hinshelwood kinetics and a weak hydrogen adsorption a suitable kinetic model was developed consistent with the experimental data.     

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     

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.     

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.     

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.     

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.     

CuO/Bi2O3催化合成3-己炔-2,5-二醇

采用均匀沉淀法在水热体系中制备出CuO/Bi2O3粉体催化剂,讨论了水解过程中pH对生成晶形沉淀的影响,通过TG分析确定合适的焙烧温度。采用XRD、SEM、BET等技术对催化剂进行了表征,结果表明,在400℃下焙烧可得到晶形完善,比表面积较大,平均尺寸0.1～0.5μm的粉体颗粒。在高压反应釜中考察了Bi质量分数、反应温度、乙炔分压、pH对催化活性的影响,得到了催化合成3-己炔-2,5-二醇的适宜反应条件:Bi质量分数12%,反应温度120℃,乙炔分压1.0 MPa,pH=6～7,产物收率达20.10%。     

强酸性树脂催化合成羧酸烯丙酯

本文讨论了利用强酸性阳离子交换树脂催化合成丙酸烯丙酯的条件,并合成了乙酸烯丙酯、丙酸烯丙酯、丁酸烯丙酯和戊酸烯丙酯。     

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.