Novel structure-defined chiral bis(oxazolinyl)thiophenes for Ru-catalyzed asymmetric cyclopropanation

The novel structures of sulfur-containing chiral bis(oxazoline) compounds which have been synthesized have been determined by X-ray crystal diffraction analyses. A high enantioselectivity (ee >99%) in the asymmetric cyclopropanation of diphenylethene with diazoester using the bis(oxazoline)-Ru(II) catalyst was obtained.     

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…     

新型手性氨基醇的合成及其用于不对称催化醛类烷基化反应

制备了一种由糖类化合物衍生的新型手性氨基醇（Ⅰ），并将其作为手性源用于醛类的不对称烷基化反应．考察了在手性氨基醇的存在下，各种醛和二乙基锌作用生成相应的手性仲醇的光学收率及化学收率．结果表明，该催化剂对于芳香醛的烷基化更为有效．并考察了几种反应条件对于苯甲醛的不对称催化烷基化反应的影响，其中最佳结果为１－苯基－１－丙醇的光学收率达８２．７％，而化学收率达５８．８％．     

（＋）－樟脑硫亚胺的合成

合成了四种含樟脑巯基手性助剂的光学活性的硫亚胺化合物。     

Enantioselective total synthesis of antiangeogenic pentaketide dimers, epoxyquinols A and B, through an asymmetric aldol approach to their common monomeric precursor

A new enantioselective total synthesis of epoxyquinols A and B possessing unique pentaketide dimeric structures and potent antiangeogenic activity was achieved by oxidative dimerization of a monomeric pentaketide precursor obtained by the Evans asymmetric aldol reaction and a series of operationally simple transformations.     

二苯并18－冠－6辅助钡离子在1，2－二氯乙烷／水微界面转移的伏安研究

应用液／液界面微电极对二苯并１８－冠－６（ＤＢ１８－Ｃ－６）辅助推动Ｂａ~（２＋）在１，２－二氯乙烷／水（ＤＣＥ／Ｗ）界面转移的电化学过程进行了详细探讨，证明该过程遵循ＴＩＣ机理，是受扩散控制的可逆过程。通过转移电流和反应物浓度之间的线性关系，测定了Ｂａ~（２＋）以及用其它方法难以测定的ＤＢ１８－Ｃ－６。     

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

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%.     

General and practical catalytic enantioselective Strecker reaction of ketoimines: significant improvement through catalyst tuning by protic additives

Significant improvement in enantioselectivity and catalyst activity was achieved for the catalytic enantioselective Strecker reaction. Using a catalyst (1-2.5 mol %) prepared from Gd(OⁱPr)₃ and d-glucose derived ligand 1, and in the presence of 2,6-dimethylphenol as an additive, high enantioselectivity was obtained from a wide range of ketoimines, including heteroaromatic and cyclic ketoimines. The new method was applied to an efficient catalytic asymmetric synthesis of sorbinil, a therapeutic agent for diabetic complications.     

新型手性双膦配体的合成及其催化性能考察

以苯乙烯为原料,通过Sharpless不对称二羟基化反应合成高对映体纯的苯基乙二醇,经环化、亲核开环和取代反应转化为手性碳膦-氧膦型双膦配体.后者与[Rh(COD)Cl]2及NH4PF6作用生成手性膦-铑阳离子催化剂.在α-脱氢氨基酸衍生物的不对称氢化反应中,化学转化率为100%,对映选择性最高达到77?.     

Enantioselective addition of aldehydes to amines via combined catalytic biomimetic oxidation and organocatalytic C-C bond formation

The biomimetic catalytic enantioselective addition of aldehydes to amines is reported. This was accomplished by combining biomimetic coupled catalytic aerobic oxidation of amines involving ruthenium-induced dehydrogenation and organocatalytic asymmetric Mannich reactions. The novel one-pot reactions furnished β-amino aldehyde and α-amino acid derivatives in high yields with excellent chemoselectivity and up to >99% ee.