L-脯氨酸催化α-酮酰胺与甲基酮的不对称直接Aldol反应

用L-脯氨酸催化α-酮酰胺与甲基酮的不对称直接Aldol反应, 获得了不同光学活性的α-羟基酰胺, 产率在21%～99%之间, 对映选择性最高达到43% ee. 加成产物的结构用元素分析、红外光谱和核磁共振进行了表征.     

氢化喹啉及其芳(杂)环稠合衍生物的合成

通过环己二酮与β-二腈基苯乙烯的Michael加成得到2-氨基-3-氰基-4-芳基-5-氧代-1,4,5,6,7,8-六氢喹啉(1); 4-苯基六氢喹啉(1a)与环己二酮发生胺的加成缩合反应生成2-N-(3-氧代-1-环己烯基)氨基-3-氰基-4-苯基-5-氧代-1,4,5,6,7,8-六氢喹啉(2), 在碱性和氯化亚铜催化下进一步环合成4-苯基-5-氨基-二-(2-氧代环己烷)并[b,g]-1,3-二氢萘啶(3). 芳醛、α-萘胺和环己二酮在乙醇中共回流, 则一锅法完成9-芳基-5,6,7,8,9,10-六氢苯并[c]吖啶酮(4)的合成. 对合成中所涉及的化学反应机理进行了尝试性的讨论. 新化合物1a～4c均经IR, ¹H NMR 及元素分析证明其结构.     

有机催化的不对称氧化反应

有机催化剂在不对称氧化反应中显示出巨大应用潜力. 综述了不同类型的有机催化剂催化的α,β-不饱和醛酮、烯烃的不对称环氧化反应及羰基化合物的不对称α-羟基化反应, 并对催化特点及催化机理作了详细的描述.     

非贵金属催化酮的不对称硅氢加成反应的研究进展

手性二级醇作为手性药物、香料等的原料,主要通过不对称加氢来制备.近来通过不对称硅氢加成的方法来制备手性醇的方法,由于其温和的反应条件及相对低廉的催化剂成本而受到广泛关注.介绍了近年来锌、铁、铜、钛等非贵金属催化剂催化潜手性酮的不对称硅氢加成反应的研究进展.     

二苯基膦功能化氧化石墨固载铂催化剂的制备及其催化烯烃硅氢加成性能

以氧化石墨为载体,采用二苯基膦配体对其进行改性,再利用膦配体对Pt的螯合配位作用合成了氧化石墨固载膦铂配合物催化剂(GO-P-Pt),并采用元素分析、FT-IR、XRD等方法对催化剂进行了表征,考察了催化剂催化不同烯烃与三乙氧基硅烷的硅氢加成反应性能。结果表明,该催化剂对烯烃与三乙氧基硅烷的硅氢加成反应具有良好的催化活性,在100℃,反应180 min后,1-辛烯的转化率为94.6%,β-加成产物的选择性高达99.4%;当底物为芳香烯烃时,β-加成产物的选择性比脂肪烯烃低。此外,催化剂在重复使用4次之后,活性基本保持不变。     

L-脯氨酸对离子液体介质中的不对称Michael反应催化性能研究

研究了L-脯氨酸对离子液体介质中醛(酮)与β-硝基烯烃的不对称Michael加成反应的催化性能, 利用X射线单晶衍射对Michael产物结构进行了表征. 结果表明, 反应在遵循胺催化机理的同时, 烯胺是从Re面对β-硝基烯烃进行加成, 产物的优势结构为(1R,2S)的syn型. 脯氨酸在离子液体1-正己基-3-甲基咪唑氯盐中显示良好的催化性能, 室温反应3～5 h, 得到89%以上收率的Michael产物, 其ee值最高70%. 脯氨酸与离子液体形成的催化体系具有良好的重复使用性能, 可至少稳定地重复使用6次.     

二苯基膦功能化氧化石墨固载铂催化剂的制备及其催化烯烃硅氢加成性能

以氧化石墨为载体,采用二苯基膦配体对其进行改性,再利用膦配体对Pt的螯合配位作用合成了氧化石墨固载膦铂配合物催化剂(GO-P-Pt),并采用元素分析、FT-IR、XRD等方法对催化剂进行了表征,考察了催化剂催化不同烯烃与三乙氧基硅烷的硅氢加成反应性能。结果表明,该催化剂对烯烃与三乙氧基硅烷的硅氢加成反应具有良好的催化活性,在100℃,反应180min后,1-辛烯的转化率为94.6%,β-加成产物的选择性高达99.4%;当底物为芳香烯烃时,β-加成产物的选择性比脂肪烯烃低。此外,催化剂在重复使用4次之后,活性基本保持不变。     

不对称催化Pictet-Spengler反应研究进展

手性四氢-β-咔啉骨架广泛存在于天然产物和药物分子中, 是其活性的关键结构. 不对称Pictet-Spengler反应是高效构建四氢-β-咔啉化合物的直接途径. 根据有机催化剂种类, 我们从手性磷酸、 手性方酰胺和其他催化剂3个方面, 综述了近5年来有机催化不对称Pictet-Spengler反应的研究进展.     

KF/Al2O3催化下4-芳基-9,10-二氢萘并[2,1-b]-4H-吡喃衍生物的合成

在KF/Al₂O₃催化下, α,β-不饱和腈或α,β-不饱和羧酸酯和7-甲氧基-1,2,3,4-四氢-2-萘酮反应, 生成了一系列4-芳基-9,10-二氢萘并[2,1-b]-4H-吡喃衍生物. 产物的结构通过红外光谱和核磁共振氢谱进行表征, 并通过X单晶衍射分析进一步证实产物的结构.     

γ-烷氧基-2(5H)-呋喃酮的合成、反应性及在合成中的应用

总结了近年来一类具有-烷氧基-2(5H)-呋喃酮结构的手性化合物的合成, 反应性的研究进展, 主要包括Michael加成、环加成、对位置的亲核进攻以及此手性建构基团在不对称合成中的应用.     

催化不对称硅氧化反应研究进展

综述了催化不对称硅氢化反应的研究进展情况，重点介绍了最近十年来手性催 化剂配体的研究情况。     

Palladium-catalyzed asymmetric hydrosilylation of 1,3-dienes

Advances in the palladium-catalyzed asymmetric hydrosilylation of 1,3-dienes are presented according to substrate types and chiral monophosphine ligands. Chiral monodentate phosphine ligands with a binaphthyl moiety have been proven to be the most efficient ligands for cyclic 1,3-dienes, and planar chiral ferrocenylmonophosphine ligands with two ferrocenyl moieties for linear 1,3-dienes. The ferrocenylmonophosphine ligands have expanded the substrate scope to 1,3-enynes in the asymmetric hydrosilylation. Palladium-catalyzed asymmetric hydrosilylation of 1,3-dienes and 1,3-enynes leads to the stereoselective synthesis of allylsilanes and allenylsilanes, respectively.     

Iron‐ and Cobalt‐Catalyzed Asymmetric Hydrosilylation of Ketones and Enones with Bis(oxazolinylphenyl)amine Ligands

Chiral bis(oxazolinylphenyl)amines proved to be efficient auxiliary ligands for iron and cobalt catalysts with high activity for asymmetric hydrosilylation of ketones and asymmetric conjugate hydrosilylation of enones.     

钯-手性膦配体催化剂在烯烃不对称催化反应中的应用

综述了钯-手性膦配体催化剂在烯烃的不对称氢氰化、不对称羰基化、不对称交叉偶联、不对称氢化硅氢化等方面的研究进展。参考文献36篇。     

Polishing a diamond in the rough: "Cu--H" catalysis with silanes

The value of a novel chemical transformation is often underappreciated at the time of its discovery. The reasons are doubtlessly manifold, but the "chemical zeitgeist" subtly determines how the new reaction will be received by the chemical community. The enantioselective reduction of carbonyls by copper-catalyzed hydrosilylation was certainly outshone by other asymmetric hydrogenation techniques. A seminal report at an early stage indicated the considerable potential of this catalytic process, yet it was disregarded for more than a decade. A refined mechanistic picture in connection with a plethora of new chiral ligands then led to copper-catalyzed 1,2- as well as 1,4-reductions of carbonyl compounds with excellent levels of enantioselection at high substrate-to-catalyst ratios and even more remarkable substrate-to-ligand ratios. The tide is turning for inexpensive copper catalysts in asymmetric hydride transfer reactions!     

Highly efficient and convenient asymmetric hydrosilylation of ketones catalyzed with zinc Schiff base complexes

Several chiral Schiff base ligands derived from α-amino acids were prepared, and zinc complexes with these chiral Schiff base ligands prepared were tested for the catalytic asymmetric hydrosilylation of ketones, and the results showed that excellent ee values were obtained, which are the prominent examples of catalytic asymmetric hydrosilylation of ketones catalyzed with zinc complexes in the presence of readily available and inexpensive α-amino acids based Schiff base ligands.     

Convenient, enantioselective hydrosilylation of imines in protic media catalyzed by a Zn-trianglamine complex

Chiral hexamine macrocycle derived from trans-1,2-diaminocyclohexane (DACH) in a complex with diethylzinc efficiently catalyzes the asymmetric hydrosilylation of N-phosphorylated aryl-alkyl or aryl-aryl ketimines in protic media with enantiomeric excess of the product approaching 100%. The cyclic structure of the trianglamine ligand increases the enantioselectivity and/or the yield of the reaction, in comparison to the catalysis by acyclic N,N'-dibenzyl-DACH ligands. Density functional theory (DFT) computations on the structure of the model ligand-zinc complex and on the structures of the pre-organized reactants together with the calculations of possible transition states allow rationalization of the direction of the asymmetric induction of the hydrosilylation reaction. This is the first example of asymmetric catalysis of the hydrosilylation reaction of ketimines with the use of a readily available and inexpensive macrocyclic trianglamine ligand.     

ASYMMETRIC HYDROSILYLATION CATALYZED BY POLYMER—SUPPORTED THIAZOLIDINE RHODIUM CATALYSTS

Asymmetric hydrisilylation catalyzed by polymeric thiazolidine rhodium catalysts was conducted.Almost the same optical yields have been obtained when comb-shaped polymeric ligands and their corresponding monomer complexed rhodium cataltysts were used to asymmetric hydrosilylation of acetophenone.Optical yield of chiral 1-methylbenzyl alcohol reaches as high as 71.5%.Temperature dependence of enantioselective hydrosilylation of acetophenone was discussed.     

Rhodium-catalysed asymmetric hydrosilylation of ketones using HETPHOX ligands

The HETPHOX ligand class was applied to the rhodium-catalysed asymmetric hydrosilylation of a range of substituted acetophenones. Enantioselective hydrosilylation of acetophenone with the tert-butyl substituted HETPHOX ligand gave (R)-phenylethanol in excellent enantioselectivity (84% ee) and in good conversion (80%). When applied to the hydrosilylation of other ketones conversions up to 93% and enantioselectivities up to 88% were observed.     

Asymmetric Hydrosilylation of Aromatic Ketones Catalyzed by an Economical and Effective Copper-Diphosphine Catalytic System in Air

In the presence of the inexpensive and non‐toxic polymethylhydrosiloxane, the combination of copper(II) acetate and a chiral diphosphine displayed high catalytic efficiency in the asymmetric hydrosilylation of a series of aromatic ketones in air atmosphere and at room temperature. (R)‐1‐Arylethanols were obtained with up to 99% yield and 93% enantiomeric excess. Meanwhile, the electron effect and steric hindrance of substituents on the aromatic ring had an interesting influence on both the yields and enantioselectivities. Furthermore, a possible mechanism was presented to explain the influence of some key factors on the reaction.