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JIANGChang-sheng LIYou-gui JIANGChen WENJi-wu YOUTian-pa 《高等学校化学研究》2003,19(2):238-239
The catalytic asymmetric cyclopropanation ofolefins with diazoacetate esters has been one of themost important methodologies for the formation ofchiral cyclopropane compounds[1,2 ] .The design andthe synthesis of an efficientcatalystare a challeng-ing task for organic chemists.The catalysts con-taining various metals and optically active ligandshave been employed for the reaction[3 ,4] . The cop-per- ( Schiff- base) complex was reported by Nazokiet al.[5] ,which exploited the area of catalyti… 相似文献
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Asymmetric cyclopropanation of diphenylethene with diazoacetates was catalyzed by new copper-(Schiff base) complexes. The
effects of the substituents in substituted salicylaldehyde on the ee's were studied, and a 94.5% ee was achieved.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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新型手性双二茂铁希呋碱亚胺配体的合成及其在不对称环丙烷化反应中的应用 总被引:3,自引:1,他引:3
以手性二茂铁乙胺为手性前体分别与吡啶二醛和吡啶二酮进行希呋碱缩合反应,合成了两种二茂铁手性亚胺膦配体,并经元素分析,^1HNMR,^31PNMR等手段进行了表征,用这类化合物作为手性配体,研究了其金属Ru(Ⅱ)配合物对苯乙烯与重氮乙酸乙酯的不对称环丙烷反应的催化作用,结果表明该类化合物的Ru(Ⅱ)配合物具有很高的催化活性。 相似文献
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Zhen QIAO Xue Yan SHI Qing Hua BIAN Shi Cong HOU Min WANG* Shandong Pesticide Research Institute Jinan College of Sciences China Agricultural University Beijing 《中国化学快报》2004,15(9)
Bis(oxazoline) ligands1 have been successfully used in a variety of metal-catalyzed asymmetric reactions, such as cyclopropanation, allylic oxidation reactions, etc; Chiral ferrocene derivatives2 have also been proved as effective ligands in numerous asymmetric reactions, for example, chiral ferrocenylphosphines exhibited high enantioselectivity for the reduction of olefins, Heck reactions and Aldol reactions of aldehydes. These results stimulated us to study the behaviour the bis(oxazoline) … 相似文献
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由新型联苯手性骨架(R)-( )-2-氨基-2′-羟基-6,6′-二甲基-1,1′-联苯la,(R)-( )-2-氨基-2′-羟基-4,4′,6,6′-四甲基-1,1′-联苯1b与不同取代基的水杨醛反应合成了9个新型席夫碱配体2a-2i,化合物的结构用核磁共振以及高分辨质谱进行表征.其中(R)-( )-2-氨基-2′-羟基-6,6′-二甲基-1,1′-联苯和3,5-二溴水杨醛衍生得到的席夫碱配体2g与Ti(O′Pr) 生成的配合物催化不对称2-甲氧基丙烯与对硝基苯甲醛的Hetero-ene反应,在-10℃反应3h时获得了最高为79?的反应产物. 相似文献
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Dr. Frady G. Adly Dr. Michael G. Gardiner Dr. Ashraf Ghanem 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(10):3447-3461
A novel approach to the design of dirhodium(II) tetracarboxylates derived from (S)‐amino acid ligands is reported. The approach is founded on tailoring the steric influences of the overall catalyst structure by reducing the local symmetry of the ligand's N‐heterocyclic tether. The application of the new approach has led to the uncovering of [Rh2(S‐tertPTTL)4] as a new member of the dirhodium(II) family with extraordinary selectivity in cyclopropanation reactions. The stereoselectivity of [Rh2(S‐tertPTTL)4] was found to be comparable to that of [Rh2(S‐PTAD)4] (up to >99 % ee), with the extra benefit of being more synthetically accessible. Correlations based on X‐ray structures to justify the observed enantioinduction are also discussed. 相似文献
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非对称双(均三唑席夫碱)衍生物的合成及抗肿瘤活性 总被引:2,自引:0,他引:2
为寻找新结构的水溶性抗癌先导化合物, 采用氨基均三唑硫代苯丙酮(1)与氨基均三唑硫醇(2a~2e)缩合得双均三唑单席夫碱化物3a~3e, 接着依次与氨基氯乙烷和水杨醛进行亲核取代和缩合反应, 分别得到含碱性侧链的单席夫碱4a~4e和非对称双席夫碱5a~5e. 所合成新化合物的结构经元素分析和光谱数据表征, 用甲基四噻唑蓝比色法(MTT)对新化合物进行了对于CHO, HL60和L1210 3种癌细胞株的体外活性试验. 在合成的15个新化合物中, 双席夫碱结构的抗癌活性最强, 其IC50值在20.0 μmol•L-1以下, 尤其是均三唑环连有双供电子取代基时(如化合物5c), 表现出潜在的活性, 其抗癌活性与上市药物比生群相当, 具有侯选药物研究的价值. 相似文献
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1,4-双(9-O-奎宁)-2,3-二氮杂萘-OsO4催化烯烃的不对称氨羟化反应 总被引:1,自引:0,他引:1
在氧化-供氮试剂N-氯代氨基甲酸苄酯存在下,1,4-双(9-O-奎宁)-2,3-二氮杂萘-OsO4催化剂在5种烯烃的不对称氨羟化反应中表现出极高的对映选择性(85%~99%e.e.)和区域选择性,产率48%~68%. 相似文献
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A C2-symmetrical aryl diphosphite derived from chiral binaphthol was prepared and its rhodium complex was used as catalysts in the asymmetric hydroformylation of olefins. High catalytic activity and good regioselectivity were observed. Up to 31.2% ee and 38.1% ee were achieved for the hydroformylation of 4-fluoro-styrene and vinyl acetate respectively. The influences of ligand-to-metal ratio, reaction temperature and the pressure of syn-gas on the enantioselectivity and regioselectivity were also studied. 相似文献
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考察了手性双膦配体DDPPI在钯催化1-辛烯及官能化端烯的不对称氢酯基化反应中的手性诱导作用,最高得到了45.2%的ee值.其中在1-辛烯的不对称氢酯基化反应中,考察了不同的膦-钯比、反应温度、压力、不同的溶剂、不同的钯催化剂前体以及助催化剂对反应的影响.其中膦,钯比在2~4的范围内,催化反应获得了较高的光学产率;以丙酮作溶剂,得到较好的催化效果. 相似文献