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1.
在温和条件合成了新型晶态层状有机聚合物-无机杂化载体材料聚(苯乙烯-苯乙烯基膦酸)-磷酸锌, 结合实验数据提出了其可能的理想结构模型. 对该载体进行氯甲基化和酚羟基化修饰后, 轴向配位固载手性Salen Mn(Ⅲ), 合成了一类新型的多相催化剂. 以间氯过氧苯甲酸为氧源, 考察了其对α-甲基苯乙烯及茚不对称环氧化反应的催化性能. 结果表明, 这类固载催化剂具有与均相Jacobsen催化剂相当或更高的催化活性和对映选择性, 并具有优良的重复使用性. 特别是在该氧化体系中, 当无助催化剂N-甲基吗啉氮氧化物(NMO)参与时, 固载催化剂获得更高的转化率及e.e.值, 这为其扩大化生产增加了可能性.  相似文献   

2.
有机聚合物-无机杂化载体-聚(苯乙烯-苯乙烯基膦酸)-磷酸氢锆-轴向固载手性Salen Mn髥催化剂,将其应用于非官能烯烃的多相不对称环氧化反应。结果表明:在没有昂贵轴向添加剂参与下,产率与对映选择性均急剧增加。以间氯过氧苯甲酸(m-CPBA)为氧化剂催化氧化α-methylstyrene,转化率从25.0%上升到98.8%;对映选择性从5.3%提高到67.3%。催化剂在循环使用5次以后,催化活性无明显改变。  相似文献   

3.
王长炜  傅相锴  黄静 《化学学报》2011,69(14):1681-1687
合成了一系列以有机聚合物-无机杂化材料聚(苯乙烯-苯乙烯基膦酸)-磷酸氢锆(ZPS-PVPA)为载体,烷氧基为连接基团的新型固载手性Salen Mn(III)催化剂,并运用FT-IR,UV-vis,XPS,SEM,TG,元素分析等手段对其进行了表征.以m-CPBA为氧化剂,茚和α-甲基苯乙烯为底物,考察了催化剂对非功能...  相似文献   

4.
以聚(苯乙烯-苯乙烯基膦酸)-磷酸氢锆(ZPS-PVPA)为催化剂载体, 通过3-氨丙基三甲氧基硅烷对其中无机磷酸氢锆的羟基进行修饰, 再与均相手性Mn(salen)催化剂进行轴向配位固载, 实现了手性均相催化剂的非均相化. 催化剂的表征结果证实制得了非均相催化剂. 随后, 考察了该非均相催化剂对α-甲基苯乙烯、 苯乙烯以及茚不对称环氧化反应的催化性能. 结果表明, 以间氯过氧苯甲酸(m-CPBA)为氧化剂, 在 0 ℃反应 3 h, 催化剂用量为 0.03 mmol, 在轴向配体 N-甲基吗啉氮氧化物(NMO)的参与下, 催化剂能高效催化α-甲基苯乙烯的不对称环氧化, 反应的对映选择性(e. e.值)可达 91.5%, 转化率为 99%. 此外, 以茚为底物考察了催化剂的循环使用性能, 结果表明, 催化剂重复使用10次后, 反应的e. e.值(>90%)远高于在相同条件下均相Mn(salen)催化剂催化茚反应的e. e.值(65%).  相似文献   

5.
以有机共聚物-无机杂化材料聚(苯乙烯-苯乙烯基膦酸)-磷酸铝(AlPS-PVPA)为载体,酚氧基为连接基团,轴向配位手性salen Mn(Ⅲ)制备了新型固载手性salen Mn(Ⅲ)催化剂,并运用FT-IR,UV-vis,XPS,SEM,TG,元素分析等手段对其进行了表征.以m-CPBA为氧化剂,茚和α-甲基苯乙烯为底物,考察了催化剂对非功能化烯烃不对称环氧化反应的催化性能.结果表明,在相同的条件下,固载催化剂3a~3d在不加助催化剂NMO时显示出了优良的催化活性,其转化率和ee值均比添加了轴向配体NMO时有很大的提高(ee%,99.2 vs.45.9; conv%,98.6 vs.64.6),这种现象与大多数文献报道相反.此外,催化剂容易分离,且回收使用9次仍能保持较好的催化活性.  相似文献   

6.
以苯乙烯-苯乙烯基膦酸共聚物、磷酸二氢钠作磷(膦)源,在温和的条件下,通过调节有机膦酸和无机磷酸的比例,合成了一系列不同化学计量比的聚(苯乙烯-苯乙烯基膦酸)-磷酸铝有机聚合物-无机杂化材料。通过FTIR、TG、N2吸附、XRD、SEM和TEM等表征手段对其进行了表征,并提出了其理想的结构模型。结果表明,这类杂化材料具有规则的层状结构和较高的热稳定性,作为催化剂载体具有潜在的应用价值。  相似文献   

7.
制备了二胺和二酚修饰的晶态有机聚合物-无机杂化载体低聚苯乙烯基膦酸-膦酸氢锆(LCZSPP)轴向固载手性Salen Mn(Ⅲ)催化剂,将其应用于非官能烯烃的多相不对称环氧化反应.研究了两类轴向连接基团及助催化剂在催化不对称环氧化反应中的影响.结果表明,通过二胺为链接基团固载的催化剂在加入轴向助剂(NMO)的情况下,转化...  相似文献   

8.
黄静  罗燕  蔡佳利 《催化学报》2016,(9):1539-1549
手性环氧化物是用途很广的中间体,通过区域和立体选择性开环反应,手性环氧化物能转化为多种对映纯的手性化合物.烯烃不对称环氧化反应是制备光学活性环氧化物的重要途径,在医药、农药和香料等精细化学品合成中具有非常重要的意义.由于salen Mn(Ⅲ)化合物在非官能团化烯烃的不对称环氧化反应中表现出高的催化活性和对映选择性,以及相对于均相手性催化,非均相手性催化具有产品易于分离和催化剂可重复利用等优点,因而成为手性催化领域的研究热点.近年来关于手性salenMn(Ⅲ)化合物的固载化研究受到广泛关注.虽然均相Mn(salen)催化剂在不对称环氧化反应方面已取得很大进展,但是在反应后处理、催化剂分离回收以及产品纯化方面也存在一定缺陷.多相salen Mn(Ⅲ)催化体系与均相催化体系相比,具有催化剂易分离回收、环境友好、产物易纯化、操作成本低和可以使用连续流反应器以及大规模生产等优点.因为在均相催化体系中,Mn(salen)Cl可能形成无活性的μ-oxo-Mn(Ⅳ)二聚体,而将salen Mn(Ⅲ)催化剂固载后则可以抑制这种二聚体的形成,并且将salen Mn(Ⅲ)催化剂多相化之后还可以促使活性位点的分离,进而增加催化剂的稳定性和保持单催化活性中心的高催化活性.本课题组近年来探索了磷酸锆与聚苯乙烯这类典型的有机功能高分子的复合,制备了一系列有机-无机杂化材料如聚(苯乙烯-异丙烯膦酸)-磷酸氢锆(ZPS-IPPA)和聚(苯乙烯-苯乙烯基膦酸)-磷酸氢锆(ZPS-PVPA),以这一系列材料为载体,通过对载体中的苯环进行氯甲基化,再接枝磺烃基、胺基或苯氧基等连接基团制备了多种非均相手性salen Mn(Ⅲ)催化剂.所制备的这些多相催化剂在催化活性、稳定性和循环使用性等方面显示出优良性能.本文在上述研究基础上,在ZnPS-PVPA的苯环上引入氯甲基,然后通过接枝芳香二胺和脂肪二胺最后轴向配位固载手性salen Mn(Ⅲ),实现了手性salen-Mn(Ⅲ)均相催化剂的多相化.并运用FT-IR,UV-Vis,XRD,TG,TEM,SEM和N2吸附-脱附等测试手段对多相催化剂进行了表征.分别以NaClO、m-CPBA和NaIO4为氧化体系考察了固载手性salen-Mn(Ⅲ)催化剂催化苯乙烯、α-甲基苯乙烯及茚的不对称环氧化反应的性能,对不同的氧化体系存有选择性;同时考察了温度、时间及溶剂等因素对催化性能的影响.考察了不同连接基团修饰的ZnPS-PVPA固载的手性salen-Mn(Ⅲ)在催化烯烃环氧化方面是否具有很好的催化性能和对映选择性.考察了助催化剂在不同的氧化体系中是否扮演着不同的角色.催化数据显示,助催化剂NMO和咪唑在催化反应中起着不同的作用.在m-CPBA氧化体系中,添加助催化剂NMO不但不能改善催化性能反而降低催化活性;在NaIO4氧化体系中,添加助催化剂咪唑略微改善了催化性能.选择催化效果最好的催化剂在m-CPBA催化体系中考察其重复使用性能,结果表明,多相催化剂经过9次循环使用,仍然显示出较好的催化性能.选择催化性能最好的多相催化剂进行环氧化反应的放大反应,结果显示,当放大倍数达到100倍时仍显示出与实验计量相当的催化性能,其转化率和ee值最高均可超过99%,具有潜在的工业应用价值.  相似文献   

9.
本文以聚(苯乙烯-异丙烯膦酸)-磷酸氢锆(ZPS-IPPA)为载体,对该载体进行氯甲基化、胺化修饰后与手性Salen Mn(Ⅲ)轴向配位,合成了一种新的固载型手性Salen Mn(Ⅲ)催化剂,采用FTIR,DR UV-Vis,XPS,SEM,TEM,TG等手段对催化剂进行表征.以次氯酸钠和间氯过氧苯甲酸为氧化剂,考察了固载催化剂对a-甲基苯乙烯不对称环氧化反应的催化性能,结果表明,固载型催化剂的催化活性比相应均相催化剂略低,但对映体选择性明显提高.在NaClO/PPNO氧化剂体系中0 ℃反应24h,a-甲基苯乙烯环氧化物的转化率达68%,e.e.值达99%.循环使用8次后催化效果无明显降低.  相似文献   

10.
使用不同空间位阻的苯氧链接手臂修饰的聚(苯乙烯基-苯乙烯膦酸)-磷酸氢锆轴向固载手性MnIII(Salen)催化剂(Cat1–Cat3),随后在间氯过氧苯甲酸(m-CPBA)为氧化剂的体系中考察了固载催化剂的催化性能.同时,在相同氧化体系下测试了一系列均相催化剂类似物(Cat4–Cat6).结果表明,在非均相条件下,可调变苯氧链接手臂的邻位取代基对催化剂活性起着重要作用,环氧化产物的对映选择性随着取代基位阻的增加而增大,但产物转化率有一定程度下降.此外,非均相催化剂即使在没有轴向助剂的参与下(通常需要添加,为了增大催化活性)仍然表现出非常高的催化活性,尤其对α-甲基苯乙烯反应,其对映选择性从6.8%增加到76.8%,转化率从19.8%上升到90.7%.制备的非均相催化剂11次的循环使用实验表明,在前5次使用后催化剂活性与对映选择性没有明显变化.  相似文献   

11.
A novel type of organic polymer-inorganic hybrid material layered crystalline zinc poly(styrene-phenylvinyl phosphonate)-phosphate (ZnPSPPP) was prepared by the reaction of styrene-phenylvinyl phosphonic acid copolymer with zinc acetate dihydrate and sodium dihydrogen phosphate. The ZnPSPPP were characterized by FT-IR, diffusion reflection UV-Vis, AAS, N(2) volumetric adsorption, SEM, TEM and TG. Unexpectedly, the layered crystalline ZnPSPPP obtained was not synthesized with traditional methods as other zinc phosphonates, but with the ones for amorphous reactions without addition of any template. It can be deduced that the layered crystalline ZnPSPPP could have potential applications for heterogeneous catalyst supports.  相似文献   

12.
A novel type of organic polymer-inorganic hybrid material layered crystalline zinc poly(styrene-phenylvinylphosphonate)-phosphate (ZnPS-PVPP) was synthesized under mild conditions in the absence of any template. And the ZnPS-PVPP were characterized by FT-IR, diffusion reflection UV-vis, AAS, N2 volumetric adsorption, SEM, TEM and TG. Notably, this method was entirely different from the traditional means used for preparing other zinc phosphonate. Moreover, it could be deduced that ZnPS-PVPP possessed the potential applications for catalyst supports. In the initial catalytic tests, the catalysts immobilized onto ZnPS-PVPP showed comparable or higher activity and enantioselectivity with that of catalysts reported by our group in the asymmetric epoxidation of unfunctional olefins.  相似文献   

13.
A novel layered organic polymer-inorganic hybrid zinc poly (styrene-phenylvinylphosphonate)-phosphate (ZnPS-PVPA) has been synthesized under mild conditions and diphenol-modified ZnPS-PVPA was used to successfully immobilize the chiral salen Mn(III) by axial coordination. The obtained heterogeneous chiral catalysts exhibited excellent activities and enantioselectivities using sodium periodate as an oxidant for asymmetric epoxidation of unfunctionalized olefins, especially for the epoxidation of α-methylstyrene (conversion: up to 97%; ee: exceed 99%). Moreover, these synthesized catalysts were relatively stable and could be expediently separated from the reaction system, and could be recycled at least ten times without obvious loss of activity and enantioselectivity. These novel catalysts could be efficiently used in large-scale reactions with the enantioselectivity being maintained at the same level, which offer a great possibility for application in industry.  相似文献   

14.
烯烃的不对称环氧化物通过选择性开环或者官能团的转化,可以生成一系列有价值的手性化合物,被广泛用作医药、农药、香料等精细化学品的合成中间体.手性Mn(salen)金属配合物被证明是烯烃不对称环氧化最有效的催化剂之一.本文综述了近年来均相手性Mn(salen)催化剂、有机聚合物固载的手性Mn(salen)、无机载体固载手性...  相似文献   

15.
A series of chiral salen Mn(iii) immobilized onto azole onium modified zinc poly(styrene-phenylvinyl phosphonate)-phosphate (ZnPS-PVPA) were prepared. The catalysts were characterized by FT-IR, diffusion reflection UV-vis, AAS, N(2) volumetric adsorption, SEM, TEM, XPS, XRD, TG and elemental analysis. The results showed that the chiral salen Mn(iii) complex was successfully immobilized onto ZnPS-PVPA. These prepared catalysts were evaluated in the asymmetric epoxidation of unfunctionalized olefins with m-CPBA and NaIO(4) as oxidants and demonstrated higher catalytic activities than those of the corresponding homogeneous chiral salen Mn(iii) catalyst under the same conditions. Moreover, these heterogeneous catalysts were stable and could be recycled nine times without significant loss of activity. Furthermore, this novel type of catalyst could also be validly used in large-scale reactions with superior catalytic disposition being maintained at the same level, which indicated the potential for applications in industry.  相似文献   

16.
以聚(苯乙烯-异丙烯膦酸)-磷酸氢锆(ZPS-IPPA)为载体,对其苯环氯甲基化、磺酸化后与手性Salen Mn(Ⅲ)轴向配位,合成了一类新的固载型手性Salen Mn(Ⅲ)催化剂,采用FTIR,XPS,SEM,TEM,N2吸附等对催化剂表征.分别在次氯酸钠溶液和间氯过氧苯甲酸氧化体系中,考察了固载催化剂对苯乙烯、α-甲基苯乙烯、茚等非功能化烯烃不对称环氧化反应的催化性能,结果表明,与均相催化剂相比,对映体选择性明显提高.尤其在m-CPBA/NMO氧化体系中0℃反应12h,茚的环氧化物的转化率及ee值均达到99%以上.并且催化剂容易分离,回收使用5次仍能保持较好的催化性能.  相似文献   

17.
Kai Yu 《Tetrahedron》2009,65(1):305-55
Two chiral Mn(III) salen complexes were immobilized onto a series of mesoporous MCM-41 and MCM-48 materials with different pore sizes and the as-synthesized catalysts were active and enantioselective for the asymmetric epoxidation of styrene and indene. The results of XRD, FTIR, DR UV-vis, and N2 sorption showed that the chiral Mn(III) salen complexes were anchored in the channels of mesoporous materials. The influence of organic silicane dosage on the catalytic performance was studied and the optimum dosage of organic silicane for preparing heterogeneous catalysts was determined. Furthermore, the effect of the fine-tuning of pore size on the performance of heterogeneous catalysts was discussed. In general, larger pore size of the supports could lead to higher conversions and the compatible pore size with substrate may be responsible for the improved enantiomeric excess (ee) values.  相似文献   

18.
Four new kinds of heterogeneous catalysts for olefins epoxidation were obtained by grafting diamines on organic polymer–inorganic hybrid material, zirconium poly (styrene‐phenylvinylphosphonate)‐phosphate (ZPS‐PVPA), and subsequently coordinating with Schiff base Mo(VI) complexes. The catalysts were characterized by IR, XPS, SEM and TEM. All catalysts were evaluated through the epoxidation of olefins using tert‐BuOOH as oxidant. The heterogeneous catalysts possess the advantages of high conversion, selectivity and excellent reusability. The catalysts were easily separated from the reaction systems and could be reused 13 times without significant loss of catalytic activity. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

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