亮点介绍

<正>手性双Salen-Ti络合物协同催化合成手性氰醇衍生物Angew.Chem.Int.Ed.2010,49,6746～6750手性氰醇在化学制药和农药合成中应用广泛,是合成α-氨基酸等生理活性化合物的重要中间体.氰化物对醛或酮的催化不对称加成是合成手性氰醇衍生物的有效方法,虽已报道了多种类型的生物催化剂和化学催化剂,但通常存在催化效率或选择性低、底物适用范围窄、催化剂昂     

光学活性氰醇的合成研究进展

光学活性氰醇是合成大量医药、农药产品的重要中间体。本文介绍了通过生物或化学催化剂进行外消旋底物的拆分或前手性底物的不对称化来制备光学活性氰醇的方法,重点讨论了有较大发展前景的有机溶剂中脂肪酶催化氰醇酯的动力学拆分的方法。     

手性Schiff Base—Ti（OR）4配合物催化醛的不对称硅腈化反应

设计合成了新型手性Ｓａｌｅｎ－Ｔｉ（ＯＲ）配合物催化剂，用其催化一系列醛的不同对称硅化反应，得到了ｅ，ｅ值为２２．４％～８７．１％的氰醇，催化剂中抗衡离子的Ｌｅｗｉｓ碱强烈地影响催化活性，但对反应的对映选择性影响很小，并探讨了其不对称催化反应机理。     

手性稀土配合物催化的亚膦酸酯对醛的不对称加成（Pudovik）反应研究

手性稀土配合物催化的亚膦酸酯对醛的不对称加成（Ｐｕｄｏｖｉｋ）反应研究钱长涛黄太生（中国科学院上海有机化学研究所金属有机化学开放实验室上海２０００３２）关键词对映选择性加成Ｐｕｄｏｖｉｋ反应手性镧配合物α－羟基膦酸酯分类号Ｏ６４３．３２光学纯的α－羟...     

氰醇酶制备手性氰醇的研究进展

手性是自然界的普遍特征 .手性药物的研制和开发 ,是现代制药行业发展的一种必然趋势 ,也是药物研究和开发中急待解决的重大课题 .利用酶的手性合成和制备手性药物中间体是当今国外医药研究的热点 .光学活性氰醇是一类重要的手性合成子 ,它很容易转化为β-氨基醇、α-羟基酸、α-羟基酮等许多手性物质 [1～ 4 ] ,进而合成其它多种光学活性化合物 ,因而在医药、农药等精细化工领域具有广阔的应用前景 ,特别对制备手性药物中间体最具发展潜力 ,它将为手性药物的研制和开发开辟一条新的途径 .手性氰醇的巨大应用价值推动了手性氰醇制备方法的发…     

柱前衍生化高效液相色谱手性固定相法拆分手性氰醇

利用正相高效液相色谱法在多糖衍生物手性固定相(OJ-H、OD-H、AD-H或AS-H)上成功地分离了一系列(31个)氰醇对映体的乙酰化或丙酰化衍生物,并拆分了3个脂肪族氰醇对映体的乙酰化衍生物。探讨了这些外消旋体在这四支手性柱上的色谱行为,通过考察流动相组成、流速、进样浓度和温度等因素对对映体拆分效果的影响,优化了色谱分离条件。方法已应用于脂肪酶催化转酯化拆分反应中手性氰醇衍生物的光学纯度的鉴定。     

手性Lewis酸催化的三甲基镓对醛的不对称加成反应

不对称碳碳键的形成是不对称催化中最活跃的领域之一,其中,二乙基锌对醛的加成一直受到广泛关注.但是最简单的甲基化试剂对醛的加成却很少提及到.有机镓铟的化合物早在1932年就已经被合成出来了,然而它们在有机合成中的应用却很少.因为它们对亲电试剂的活性较低,而且对水,空气很不稳定.我们在研究中发现,在强的Lewis酸(TiCl4)的催化下,三甲基镓能对醛进行加成,得到甲基醇.我们使用手性叔胺为手性配体,与TiCl4来催化三甲基镓对醛的加成,可以得到具有光学活性的甲基醇,首次实现了以GaMe3为烷基化试剂对醛的不对称加成反应.     

氰化钠和醛及苦杏仁粗酶一锅法合成手性氰醇

直接使用固体氰化钠代替易挥发的HCN为氰源,用来源于苦杏仁的(R)-醇腈酶粗酶催化和醛的反应,并加入足量的HOAc来抑制非酶促反应和手性氰醇产物的外消旋化,一锅法合成了手性氰醇.考察了酸、(R)-醇腈酶粗酶、水、氰化钠和反应温度等因素对反应的影响.大部分反应底物的产物的产率及ee值都大于95%.该方法简单、安全、低成本、高对映选择性和收率,具有很好的应用价值.     

醛酮的不对称硅氰化反应研究进展

羰基化合物的不对称氰醇化反应是当前不对称催化领域里的一个研究热点.具有光学活性的氰醇是有机合成的重要中间体,通过官能团转化可以很容易制备出一些在天然产物和化学制药中具有重要意义的手性化合物,如β-氨基醇、α-氨基酸和α-羟基酸等.目前,不对称催化的三甲基氰硅烷与醛酮的加成反应作为手性氰醇的主要化学合成方法受到人们的广泛关注,而反应体系中采用的手性配体与Lewis酸是控制这类反应的效能和立体选择性的关键,因此,主要就三甲基氰硅烷和醛酮不对称加成反应中催化体系的发展作了一个简要的述评.     

光学活性芳族氰醇的合成及其稳定性的研究

光学活性芳族氰醇以及由它转变而成的α-羟基酸、α-羟基酯、α-羟基酮和β-羟基胺等光学活性异构体都是重要的农药和医药中间休,从实用观点看,利用催化不对称合成来制取光活性氰醇,更具有重要意义。近年来,环状二肽Cyclo[L(D)-Phe-L(D)-His]用于催化芳族氰醇的不对称合成,由于具有与D-羟腈酶相类似的高活性和高对映选择性,尤为     

Catalytic asymmetric borane reduction of prochiral ketones using chiral camphor-derived mercapto-alcohols

Easily available D-(+)-camphor-derived chiral mercapto-alcohols 2 and 3 were employed for catalytic asymmetric borane reduction of aromatic ketones. Moderate enantioselectivities with e.e. 20.2-72.1% were obtained with 10 mol% catalyst. Opposite asymmetric induction was achieved when mercapto-alcohols 2 and 3 were used.     

Reduction of Sulphur-containing Aromatic Nitro Compounds with Hydrazine Hydrate over Iron(III) Oxide-MgO Catalyst

Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron(III) oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.     

PEG型酸性温控离子液体中芳香酸和醇的酯化反应

报道了该催化体系在芳香酸和醇酯化反应中的应用. 研究发现, 该离子液体具有优良的催化性能, 产品易分离, 催化剂可循环使用且活性不降低, 催化剂不易流失, 实现了均相催化剂的高效回收和再利用.     

Organocatalytic regio- and asymmetric C-selective S(N)Ar reactions-stereoselective synthesis of optically active spiro-pyrrolidone-3,3'-oxoindoles

The first example of catalytic enantioselective nucleophilic aromatic substitution of beta-dicarbonyl compounds is presented. An O-benzoylated cinchona alkaloid derivative catalyst gave a selective C-arylation reaction compared to, e.g., the corresponding benzylated catalyst which provided a 1:1 mixture of the C- and O-arylation products. The reaction proceeds well for various aromatic compounds with different 1,3-dicarbonyl compounds, and the optically active products are obtained in very high yields and with up to 92% ee. One further scope of the organocatalytic enantioselective nucleophilic aromatic substitution reaction is demonstrated by the synthesis of the optically active spiro-pyrrolidone-3,3'-oxoindole structure.     

Amide Ionic Liquids（AILs）/L-Proline Synergistic Catalyzed Asymmetric Mannich Reactions

IntroductionThe Mannich reaction is one of the most importantreactions for the formation of C—C bonds in the organicsynthetic chemistry, and this reaction has been widelyused for the synthesis of secondary and tertiary aminederivatives that is considered…     

Ferric hydroxide supported gold subnano clusters or quantum dots: enhanced catalytic performance in chemoselective hydrogenation

An attempt to prepare ferric hydroxide supported Au subnano clusters via modified co-precipitation without any calcination was made. High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) have been employed to study the structure and chemical states of these catalysts. No Au species could be observed in the HRTEM image nor from the XRD pattern, suggesting that the sizes of the Au species in and on the ferric hydroxide support were less than or around 1 nm. Chemoselective hydrogenation of aromatic nitro compounds and alpha,beta-unsaturated aldehydes was selected as a probe reaction to examine the catalytic properties of this catalyst. Under the same reaction conditions, such as 100 degrees C and 1 MPa H2 in the hydrogenation of aromatic nitro compounds, a 96-99% conversion (except for 4-nitrobenzonitrile) with 99% selectivity was obtained over the ferric hydroxide supported Au catalyst, and the TOF values were 2-6 times higher than that of the corresponding ferric oxide supported catalyst with 3-5 nm size Au particles. For further evaluation of this Au catalyst in the hydrogenation of citral and cinnamaldehyde, selectivity towards unsaturated alcohols was 2-20 times higher than that of the corresponding ferric oxide Au catalyst.     

Pt/NbPWO双功能催化剂的制备及氢解碱木质素制备芳香单体

木质素是一种天然芳香族聚合物,约占木质纤维素的30%,是唯一通过裂解C―O醚键和C―C键生产芳香族化学品或液体燃料的可再生芳香族资源。迄今为止,对木质素氢解制备有价值化合物的研究主要集中在相对不稳定的C―O键的裂解上,这限制了木质素氢解的效率。采用水热法和湿浸渍法制备了多功能Pt/NbPWO催化剂。通过破坏碱木质素中的C―O键和C―C键,可以得到产率为18.02%的芳香族单体。该反应不仅可以断裂木质素聚合物中醚键,同时也可以断裂部分关键的C―C键。其氢解机理可能是丰富的Brønsted酸和Lewis酸位点参与了C―C的活化。此外,重点分析载体和Pt物种在Pt/NbPWO催化剂中的协同作用。     

杂双金属复合物ZABDP催化芳香酮与芳香醛的直接不对称Aldol反应

合成了新型的手性铝/锌杂双金属复合物(R,S,S)-3,3'-二[(N-二苯基脯氨醇)甲基]-2,2'-二羟基-1,1'-联萘酚铝/锌复合物(ZABDP).在催化芳香酮与芳香醛的羟醛缩合(Aldol)反应中,该复合物中的铝作为路易斯酸活化醛,锌的烷氧化物作为Br?nsted碱,使苯乙酮形成活性锌的烯醇化物,2种金属的应用使得芳香醛与芳香酮的直接不对称Aldol反应顺利进行,反应的对映选择性最高达90%,产率最高达99%.     

Pt/NbPWO双功能催化剂的制备及氢解碱木质素制备芳香单体

Lignin is a natural aromatic polymer that accounts for nearly 30% of lignocellulose and is considered the only renewable aromatic (re)source for producing aromatic chemicals or liquid fuels via the cleavage of C―O ether bonds and C―C bonds. Thus far, the majority of investigations involving the production of valuable compounds via lignin hydrogenolysis have focused on the cleavage of relatively labile C―O bonds only, which restricts the efficiency of hydrogenolysis. Therefore, in this work, a bifunctional Pt/NbPWO catalyst was synthesized using hydrothermal and wet impregnation methods. It was found that aromatic monomers with a yield of 18.02% could be obtained by breaking the C―O and C―C bonds in alkali lignin. This reaction was applicable to breaking the key C―C bonds when the C―O ether bonds were broken in lignin polymers. The hydrogenolysis mechanism most likely involves the abundant Brønsted acid and Lewis acid sites on the catalyst that facilitate C―C bond activation. Additionally, the synergy between the support and Pt species in the Pt/NbPWO catalyst was primarily emphasized.     

均相苯乙酮加氢反应研究

合成了一种新的钌膦配合物[RuCl2(Dmpp)2en](Dmpp=4-(2，6-二甲氧吡啶基)二苯基膦，en=乙二胺)，对其结构进行了表征．系统研究了反应温度，氢气压力，底物和催化剂的比例，碱和催化剂的比例等反应条件对[RuCl2(Dmpp)2en]催化的芳香酮加氢反应活性的影响，证明其在苯乙酮加氢反应中具有很好的催化活性．