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用自由配体法将对称、不对称Co(II)Salen型席夫碱配合物封装于Y型沸石分子筛的超笼中,并采用FTIR、UV-Vis、热分析和催化技术研究了其空间结构和催化性能.结果表明,被封装于分子筛超笼中的Salen型席夫碱配合物,同样具有未封装配合物的物理化学性能,也没有影响分子筛的框架结构;在以O2作氧化剂,催化苯乙烯环氧化反应中表现了非常高的反应活性和稳定性;金属配合物的量子化学密度泛函计算结果揭示了配合物的催化性能与轨道能量密切相关. 相似文献
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Y型分子筛中对称与不对称Co(II)Salen型席夫碱配合物的结构和催化性能 总被引:1,自引:0,他引:1
用自由配体法将对称、不对称Co(II)Salen型席夫碱配合物封装于Y型沸石分子筛的超笼中, 并采用FTIR、UV- Vis、热分析和催化技术研究了其空间结构和催化性能. 结果表明, 被封装于分子筛超笼中的Salen型席夫碱配合物, 同样具有未封装配合物的物理化学性能, 也没有影响分子筛的框架结构;在以O2作氧化剂, 催化苯乙烯环氧化反应中表现了非常高的反应活性和稳定性;金属配合物的量子化学密度泛函计算结果揭示了配合物的催化性能与轨道能量密切相关. 相似文献
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不添加任何稳定剂,在碱性条件下制备了5%Ir/SiO2催化剂,并用于催化苯乙酮的不对称加氢反应中,详细考察了碱和手性修饰剂种类、氢气压力、反应温度、(1S,2S)-1,2-二苯基乙二胺((1S,2S)-DPEN)浓度对反应的影响.在优化反应条件下,5%Ir/SiO2催化剂表现出较好的反应活性和对映选择性.其中,苯乙酮不对称加氢反应的对映选择性达70%.该催化剂不需要任何稳定剂,制备方法简单,催化性能稳定,通过简单的离心分离即可循环使用. 相似文献
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不添加任何稳定剂,在碱性条件下制备了5%Ir/SiO2催化剂,并用于催化苯乙酮的不对称加氢反应中,详细考察了碱和手性修饰剂种类、氢气压力、反应温度、(1S,2S)-1,2-二苯基乙二胺((1S,2S)-DPEN)浓度对反应的影响.在优化反应条件下,5%Ir/SiO2催化剂表现出较好的反应活性和对映选择性.其中,苯乙酮不对称加氢反应的对映选择性达70%.该催化剂不需要任何稳定剂,制备方法简单,催化性能稳定,通过简单的离心分离即可循环使用. 相似文献
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在温和的条件下制备了负载型3%(w)Ir/SiO2/2TPP(三苯基膦)催化剂, 并且考察了(1S,2S)-1,2-二苯基乙二胺[(1S,2S)-DPEN]作为手性修饰剂对其催化苄叉丙酮不对称加氢反应性能的影响. 结果表明, 手性修饰剂(1S,2S)-DPEN的加入, 对苄叉丙酮不对称加氢反应活性和C=O加氢的选择性都有很好的促进作用. 经优化条件, 在40 ℃下, LiOH浓度为0.375 mol·L-1的甲醇溶液中, 氢气压力为6 MPa, 反应8 h后, 苄叉丙酮的转化率大于99.0%, 对不饱和醇的选择性大于99.0%, 不饱和醇的对映选择性(ee)值达到48.1%. 相似文献
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设计合成了一种新型的钌-双膦-手性二胺三元配合物RuC l2(BDPX)[(S,S)-DPEN][BDPX=邻-二(二苯基膦)甲苯,DPEN=1,2-二苯基乙二胺].利用此配合物作催化剂催化了苯乙酮和几种取代苯乙酮的不对称氢化反应;考察了多种因素对苯乙酮不对称氢化反应的转化率和ee值的影响.结果表明,此配合物对苯乙酮进行不对称氢化反应具有良好的催化性能和较高的对映选择性,在优化的条件下,当苯乙酮、配合物的摩尔比为20000?1时,其不对称氢化反应的转化率可达到100%,其ee值可达到59.0%;对取代苯乙酮的不对称氢化反应也具有一定的催化活性和中等的对映选择性. 相似文献
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制备了以三苯基膦(PPh3)作为助剂的Ru-Rh/γ-Al2O3 催化剂, 在氢氧化钾的异丙醇溶液中, 用(1S, 2S)-DPEN [(1S, 2S)-1,2-diphenylethane-1,2-diamine]作手性修饰剂对苯乙酮及其衍生物进行不对称催化加氢, 此催化剂表现出较高的催化活性和良好的对映选择性. 优化反应条件, 苯乙酮、乙基苯基酮和异丙基苯基酮的转化率分别达到92.5%, 95.9%, 100%, 生成(R)-构型产物的ee值分别达到79.6%、81.2%和81.4%. 相似文献
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在碱性条件下制备了三氧化二铝负载的铱(Ir/γ-Al2O3)催化剂,并用于苯乙酮及其衍生物的不对称催化加氢反应.考察了不同的碱、碱浓度、手性二胺(1S,2S)-1,2-二苯基乙二胺[(1S,2S)-DPEN]浓度、反应温度和反应压力对催化剂及反应的影响.结果显示,在优化反应条件下,该催化剂表现出较高的催化活性和良好的对映选择性,其中异丁酰苯不对称催化加氢反应的对映选择性达到了80.3%.该催化剂不需要使用任何稳定剂,制备方法简单,催化性能稳定,通过简单的离心分离即可循环使用. 相似文献
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报道了配合物RuCl2(BISBI)[(R,R)-DPEN] [BISBI=2,2'-二(二苯膦亚甲基)-1,1'-联苯, DPEN=1,2-二苯基乙二胺]的合成和表征, 并研究了其在苯乙酮不对称加氢反应中的催化性能. 考察了底物/催化剂物质的量比、碱浓度、反应温度和氢气压力等对催化活性和对映选择性的影响, 在苯乙酮/KOH/催化剂的物质的量比为30000∶250∶1, 氢气压力为2 MPa, 反应温度为35 ℃时, 苯乙酮的转化率和生成α-苯乙醇的对映选择性分别达到了100%和65% ee. 相似文献
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ChaoFen Yang HeYan Jiang Jian Feng HaiYan Fu RuiXiang Li Hua Chen XianJun Li 《Journal of molecular catalysis. A, Chemical》2009,300(1-2):98-102
A series of silica (SiO2) supported iridium catalysts stabilized by cinchona alkaloids was prepared and applied in the heterogeneous asymmetric hydrogenation of acetophenone. Cinchona alkaloids exhibited a marked ability to stabilize and disperse the Ir particles. In the presence of (1S,2S)-diphenylethylenediamine ((1S,2S)-DPEN)) as chiral modifier, the cinchonidine (CD) stabilized catalyst 5%Ir/2CD-SiO2 exhibited excellent catalytic performance in the asymmetric hydrogenation of acetophenone in MeOH. Under the optimum conditions, the ee value of (R)-phenylethanol achieved 79.8% and no other product was produced, a higher enantioselectivity than that reported up to now for acetophenone hydrogenation catalyzed by the supported metal catalysts modified by chiral reagents. In particular, a synergistic effect between (1S,2S)-DPEN and CD was observed, which significantly accelerated the reaction rate and enhanced the enantioselectivity. The catalyst can be reused several times without a significant loss of activity and enantioselectivity. 相似文献
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Dichlorocobalt(III) complexes of (2S,5S,9S)-trimethyltriethylenetetraamine (L1) and (2S,5R,9S)-trimethyltriethylenetetraamine (L2) have been prepared. Both L1 and L2 coordinate to the cobalt(III) ion to give three isomers: Λ-cis-α, Δ-cis-β, trans isomers for L1 and Δ-cis-α, Δ-cis-β, trans isomers for L2. Each of the trans-dichloro complexes of the two ligands have been isomerized stereospecifically to the cis-α-dichloro complex in methanol, and each of the cis-α-dichloro complexes stereospecifically to the trans-diaqua complex in water. Both the geometrical and optical inversions took place at the same time in the observed stereospecific isomerizations. 相似文献
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Based on (1R,2R)-(+)-(1,2)-DPEN skeleton, a series of primary amine–sulfamide bifunctional catalysts were synthesized, which exhibited excellent catalytic performance in the Michael addition of acetone to β-nitrostyrene. Therefore, a trifunctional heterogeneous catalyst was designed and prepared by simple N-sulfonyl reaction of (1R,2R)-(+)-(1,2)-DPEN and sulfonyl chloride resin. It was employed for the aforementioned addition without any additive and satisfactory results (80.5% conversion; 84.3% ee) were obtained. Meanwhile, the structural and textural properties of the catalyst were characterized by infrared spectroscopy (FT-IR), elemental analysis, SEM, and N2 adsorption and desorption experiments. Finally, the generality of the catalyst was investigated. 相似文献
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合成了(R,R)-1,2-二苯基乙二胺((R,R)-DPEN)、 钌和三苯基膦的三元配合物RuCl2[P(C6H5)3]2-(R,R)-DPEN, 并将其用于萘乙酮的不对称加氢反应. 考察了碱/催化剂的摩尔比、反应温度和氢气压力等对催化活性和对映选择性的影响. 结果表明,多种因素对反应的转化率和对映选择性均有影响. 在萘乙酮:(CH3)3COK:催化剂摩尔比为 50000:450:1, 氢气压力为4 MPa, 反应温度为25 ℃的条件下,反应16 h时,萘乙酮生成α-萘乙醇的产率和对映选择性分别达到了100%和83%. 相似文献
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Lu Yin Wenjun Shan Xingshu Li Albert S.C. Chan 《Journal of organometallic chemistry》2009,694(13):2092-111
The preparation of methyl (R)-o-chloromandelate via Ru-catalyzed asymmetric hydrogenation and transfer hydrogenation was investigated. With Ru-(R,R)-2,4,6-triisopropyl C6H2SO2-DPEN as the catalyst and HCOOH-Et3N azeotrope as the hydrogen donor, up to 92% ee was obtained in an optional condition. The synthesis of (S)-Clopidogrel was also studied. 相似文献
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E. R. Latypova A. V. Bannova R. R. Muslukhov M. A. Shutova R. F. Talipov G. Yu. Ishmuratov 《Chemistry of Natural Compounds》2010,46(3):370-372
New capabilities for the synthetic use of (R)-4-menthen-3-one were demonstrated using as examples (3S)-methylundec- and (2S)-methyldec-1-ylbromides, key synthons for (S,S,S)-diprionylacetate (sex pheromone of pine sawflies of genera Diprion and Neodiprion). 相似文献
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An easy and efficient one-pot reaction from readily available 2-(N-Cbz) aminocyclobutanone selectively gave, by means of an asymmetric Strecker synthesis in the presence of a chiral benzylic amine, the thermodynamic 1,2-diamino nitriles. Basic hydrolysis, cleavage of the benzylic group and acidic hydrolysis of the resulting trans-1,2-diaminocyclobutanecarbonitrile gave, in a four-step sequence from the ketone, (1S,2S)- or (1R,2R)-1,2-diaminocyclobutanecarboxylic acid, ornithine derivatives. The absolute configuration has been established by X-ray analysis of the corresponding trans-diamino amide. 相似文献
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采用浸渍法在温和条件下制备了羟基磷灰石负载的铱催化剂(Ir/HAP), 并以X射线衍射(XRD), 透射电子显微镜(TEM), X射线光电子能谱(XPS), 比表面积测定(BET)以及附带能量散射X射线谱的扫描电子显微镜(SEM-EDS)等手段对载体和催化剂进行了表征. 以(1S,2S)-1,2-二苯基乙二胺((1S,2S)-DPEN)为手性修饰剂时, 该催化剂对苯乙酮及其衍生物不对称加氢反应表现出较高活性和对映选择性(ee). 在氢气压力为3.0 MPa、303 K条件下反应3 h, 苯乙酮及其衍生物的加氢转化率在94.7%以上, 其中生成2'-(三氟甲基)苯乙醇的对映选择性高达81.5%. 在不使用其它配体作稳定剂的情况下, 该结果比目前文献报道值高. 通过对比研究发现, 羟基磷灰石作为载体优于二氧化硅等其它无机载体. 催化剂通过简单离心分离可循环使用多次, 无明显的金属铱流失. 相似文献