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1.
《有机化学》2009,29(3)
α-手性酮化合物是一类重要的合成中间体.至今已有很多工作致力于在酮羰基α-位构建手性中心,但由于产物易于消旋,有效地不对称催化合成α-手性酮化合物的方法非常有限.从结构看通过α,β-不饱和酮的还原是一个构建酮羰基α-位手性中心的直接方法,但α,β-不饱和酮的还原往往是羰基而不是双键被还原.中国科学院上海有机化学研究所侯雪龙小组发现,利用Phosphinooxazoline(PHOX)为配体的Tr催化剂1能有效地催化氢化α,β-不饱和酮的碳碳双键,  相似文献   

2.
3类手性配体d-10-樟脑磺酸及其衍生物,α-(-)-羟蒎酮及其衍生物,又恶唑啉6衍生物分别与铜(Ⅱ)形成手性铜配合物,催化重氮乙酸酯与1,1-二苯乙烯或异丁烯的环丙烷化加成反应,得到光学活性环丙羧酸酯,不对称诱导最高可达95%e.e.。  相似文献   

3.
合成了3种4-酰基-双(1,3-二苯基-5-吡唑啉酮),1,5-双(1′,3′-二苯基-5′-吡唑啉酮-4′-基)-1,5-戊二酮;1,6-双(1′,3′-二苯基-5′-吡唑啉酮-4′-基)-1,6-己二酮和1,10-双(1′,3′-二苯基-5′-吡唑啉酮-4′-基)-1,10-癸二酮,通过元素分析,红外光谱和核磁共振氢谱对产物组成进行了表征,合成了它们的Tb(Ⅲ)二元和三元[1,10-二氮杂菲(Phen)或2,2′-联吡啶(Dipy)]配合物,测定了配合物的荧光光谱,对其荧光性质进行了研究,结果表明,配合物发射Tb(Ⅲ)的特征荧光,4-酰基0双(1,3-二苯基-5-吡唑啉酮)配体的三重态能级与Tb(Ⅲ)的最低激发态(5D4)能级匹配较好,配合物荧光强度随4-酰基-双(1,3-二苯基-5-吡唑啉酮)配体2个吡唑环间碳链的增长而减弱,第2配体Phen和Dipy具有荧光增强作用,且前者优于后者。′  相似文献   

4.
重点报道了以(1R,2S)或(1S,2R)-1,2-二苯基-2-氨基乙醇衍生物手性配体的合成及其用于不对称催化反应的研究,如去氢氨基酸的氢化、醛的乙基锌加成、酮的还原、活泼亚甲基化合物的烷基化、醛的硅腈化和瑞福马斯基反应等.研究了手性配体的结构、底物和反应条件等对上述反应的对映选择性和催化活性的影响.  相似文献   

5.
用丙二酸酯法合成了N-乙酰基-3-(2-萘基)-DL-α-丙氨酸乙酯3.3经酶法拆分,得光学活性的D-3,后者经盐酸水解、酯化后再与苯基溴化镁作用,制得标题化合物6。在0.5mmol6存在下,用过量硼烷对一系列前手性酮还原,得到了相应的光学活性二级醇。对映体过量(e.e值)57.0~100%。  相似文献   

6.
合成了铽与1-苯基-3-甲基-4-异丁酰基吡唑啉酮和不同中性配体的4个三元配合物Tb(PMIBP)3.2H2O、Tb(pmibp)3.Dipy、Tb(PMIBP)3、Phen和Tb(PMIBP)3.2TPPO(Dipy=2.2’-联吡啶、Phen=1,10-邻菲罗啉,TPPO=三苯基氧膦)。  相似文献   

7.
新型手性配体的设计合成是不对称催化研究的重要内容,其中手性胺膦配体因同时含有"软"的磷原子和"硬"的氮原子而具有丰富的配位化学性能和优秀的不对称诱导能力.本文总结了本研究组最近设计合成的手性环状胺膦配体的制备、表征及其在铁催化酮的不对称还原中的应用.手性1,2-环己二胺与双(2-甲酰基苯基)苯基膦通过[2+2]环缩合反应能够顺利获得手性22元环的亚胺膦配体21,该配体经Na BH4还原后生成大环胺膦配体22.利用手性大环胺膦配体22与Fe3(CO)12原位生成的催化体系,能够高活性、高对映选择性地实现包括杂环芳香酮在内50多种酮的不对称转移氢化和不对称氢化反应,其S/C(底物与催化剂的摩尔比)最高可达5000:1,产物手性芳香醇的光学纯度高达99%ee.  相似文献   

8.
刘湘  李纪国 《应用化学》1997,14(4):88-90
奎宁与钴(Ⅱ)手性络合物用于前手性酮的不对称催化还原刘湘*李纪国张正(无锡轻工大学化工系无锡214036)(南京大学化学系南京)关键词手性络合物,不对称还原,前手性芳香酮1996-10-25收稿,1997-04-22修回前手性酮的不对称催化还原作为光...  相似文献   

9.
王彩兰  王玉炉 《合成化学》1998,6(4):358-364
综述了α,β-不饱和醛、酮的1,2-选择性还原方法。全面介绍了选择性还原羰基的各种方法及特点,同时也描述了一些反应机理。  相似文献   

10.
以手性醇修饰LiAlH4不对称还原α—亚胺酮   总被引:2,自引:0,他引:2  
张静  刘晖 《化学通报》1997,(10):46-47,50
以手性醇修饰LiAlH4不对称还原α-亚胺酮张静刘晖*王东眭秀楣(中国科学院化学所北京100080*北京大学化学系100871)不对称还原羰基合成光活性的醇是一个重要的研究领域。其中α-不饱和酮,如:α-酮酯,α-烯基酮的不对称还原的研究已有不少报道...  相似文献   

11.
Sodium nitrate was used as an effective redox mediator in the electrochemical oxidation of primary and secondary aromatic alcohols in biphase electrolysis at ambient temperature. The oxidation reactions were carried out in an undivided cell equipped with carbon anode and stainless steel cathode in which upper aqueous phase contained 0.83% sodium nitrate with minimum amount of HCl whereas, the lower organic phase consisted of aromatic alcohols in chloroform. A variety of aromatic alcohols were efficiently oxidized to aldehydes and ketones in good yields with maximum selectivity (>99%).  相似文献   

12.
《Tetrahedron: Asymmetry》2007,18(6):734-741
A new series of amino alcohols with a chiral cyclopropane backbone have been developed and used in the catalytic asymmetric diethylzinc addition and phenyl transfer to various types of aldehydes. These cyclopropane-based chiral amino alcohols show high enantioselectivity in the addition of organozincs to aromatic and aliphatic aldehydes. For diethylzinc addition to aromatic and aliphatic aldehydes, up to 97% ee and 93% ee are obtained, respectively. For the phenyl transfer to aromatic aldehydes, the best enantioselectivity was 89% ee.  相似文献   

13.
A novel method for the one pot synthesis of N-alkyl arylamines from nitro aromatic compounds and alcohols is proposed through the combination of the aqueous-phase reforming of alcohol for hydrogen production, the reduction of nitro aromatic compounds for the synthesis of aromatic amine and the N-alkylation of aromatic amine for the production of N-alkyl arylamine over an identical catalyst under the same conditions of temperature and pressure in a single reactor. In this process, hydrogen generated from the aqueous-phase reforming of alcohols was used in-situ for the hydrogenation of nitro aromatic compounds for aromatic amine synthesis, followed by N-alkylation of aromatic amine with alcohols to form the corresponding N-alkyl arylamines at a low partial pressure of hydrogen. For the system composed of nitrobenzene and ethanol, under the conditions of 413 K and PN2 = 1 MPa, the conversion degrees of nitrobenzene and aniline were 100%, the selectivity to N-ethylaniline and N, N-diethylaniline were 85.9% and 0%-4%, respectivity, after reaction for 8 h at the volumetric ratio of nitrobenzene:ethanol:water = 10:60:0. The selectivity for N, N-diethylaniline production is much lower than that through the traditional method. In this process, hydrogen and aromatic amines generated from the aqueous-phase reforming of alcohols and hydrogenation of nitro aromatic compounds, respectively, could be promptly removed from the surface of the catalyst due to the occurrence of in-situ hydrogenation and N-alkylation reactions. Thus, this may be a potential approach to increase the selectivity to N-alkyl arylamine.  相似文献   

14.
以高压反应釜为反应装置,采用CuI/Bipy(2,2'-联吡啶)/TEMPO(2,2,6,6-四甲基哌啶氧化物)催化体系,以氨水作氮源,分子氧作氧化剂,对醇催化氧化生成相应腈的方法进行了优化。 以苯甲醇的催化氧化反应为模型反应,考察了催化剂及其用量、溶剂、反应温度以及时间对催化性能的影响。 实验表明:在高压釜中,120 ℃、40×105 Pa的氮氧混合气(φ(O2)=8%)条件下,将催化剂摩尔分数降低至1%(脂肪醇催化剂摩尔分数为5%),反应时间缩短至8 h时,催化效果最佳。同时,该反应系统对于不同的芳香醇和脂肪醇的氧化均取得了90%以上的转化率和90%以上的产品收率。  相似文献   

15.
《Tetrahedron: Asymmetry》2001,12(15):2147-2152
A series of binaphthyl-derived amino alcohols were synthesized and used as catalytic ligands in the asymmetric alkynylation of aromatic aldehydes in the presence of a dialkylzinc reagent. The alkynylation of a variety of aromatic aldehydes gave the corresponding chiral propargylic alcohols in 61–93% e.e.  相似文献   

16.
Al2O3/NaOH固相条件下研磨Cannizzaro反应的研究   总被引:1,自引:0,他引:1  
田大年  刘万毅 《有机化学》2006,26(11):1525-1528
将芳香醛与氧化铝负载的固体碱氢氧化钠混合于研钵中, 在室温下研磨5~10 min, 可得相应的芳香醇和芳香酸, 产率在80%~99%. 该法反应条件温和、操作简便、收率高.  相似文献   

17.
Asymmetric reduction of aromatic ketones, with the reagent (1) prepared from borane-methyl sulfide (EMS) and (15, 25)-(+)-2-amino-3-methoxy-1-phenyl-1-propanol (3a) yielded the corresponding alcohols in 30–65% e.e. This reagent (1) is also effective for the asymmetric hydroboration of 2-phenyl-1-alkenes, isoelectronically similar to the aromatic ketones, and yielded the corresponding alcohols in 8–37% e.e.  相似文献   

18.
Various primary alcohols, particularly benzylic alcohols, could be converted into the corresponding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq. NH3, followed by reaction with ∼30% aq H2O2. Similarly, various benzylic halides could be also converted into the corresponding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq NH3, followed by reaction with ∼30% aq H2O2. The present reactions involve the metal-free one-pot oxidative conversion of benzylic alcohols and benzylic halides into the corresponding aromatic amides, respectively.  相似文献   

19.
《Tetrahedron: Asymmetry》2006,17(1):112-115
Novel spiroborate esters derived from nonracemic 1,2-amino alcohols were examined as chiral catalysts in the borane reduction of acetophenone and other aromatic ketones at room temperature. The optically active alcohols were obtained in excellent chemical yields and enantioselectivities up to 99% ee with 10% of catalyst.  相似文献   

20.
Nitro‐aromatic compounds can be photocatalytically reduced into the corresponding amine‐aromatic compounds using TiO2 as a photocatalyst in the UV/TiO2/holes scavenger and Vis/TiO2/dye‐sensitized systems. In the UV/TiO2/holes scavenger system, reaction substrate alcohols such as methanol could be used as the holes scavengers, and in the Vis/TiO2/dye‐sensitized system, substrate alcohols could be oxidized to the corresponding aldehydes with high selectivity. When methanol was used as the holes scavengers and the illumination time was 6 h, 87.2% of p‐nitrotoluene could be photocatalytically reduced into p‐toluidine. In the Vis/TiO2/dye‐sensitized system, the effect of aromatic alcohols for the photocatalytic reduction of nitrobenzene was better than that of other alcohols. At the same time, aromatic alcohols can be easily oxidized, and the production efficiencies of the corresponding aldehydes were higher than those of other alcohols. The possible reaction mechanisms were also proposed.  相似文献   

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