惰性金属催化不对称硫醚氧化

药物中多数使用的为低于50个原子组成的有机小分子,这些小分子中很多具有手性,药理作用是药物小分子通过与体内大分子之间严格手性匹配识别实现的。手性亚砜作为重要的手性中间体、手性配体、辅剂、催化剂和手性药物,光学纯度的手性亚砜是很多药物的活性基团,所以对潜手性的硫醚的不对称催化氧化以达到高光学纯度是具备重大意义的。本文对钛催化硫醚氧化及其相关体系作简要的介绍,然后再进一步介绍亚砜作为药物方面的应用。     

Concise Catalytic Asymmetric Total Synthesis of Biologically Active Tropane Alkaloids

A general strategy for the total asymmetric synthesis of valuable tropane alkaloids by catalytic stereoselective transformations is disclosed. The power of this approach is exemplified by the concise catalytic enantioselective total syntheses of (+)‐methylecgonine, (−)‐cocaine and (+)‐cocaine as well as the first catalytic asymmetric total syntheses of a cocaine C‐1 derivative and (+)‐ferruginine starting from 5‐oxo‐protected‐α,β‐unsaturated enals using only two and three column chromatographic purification steps, respectively.     

合成肽在不对称催化反应中的应用

综述了合成肽作为催化剂在不对称催化反应中的应用,总结了各种合成肽催化剂的结构及其在催化不同类型反应如氰醇化反应、Strecker反应、Aldol反应、Michael加成反应、Morita-Baylis-Hillman反应和Stetter反应等中的催化活性及影响因素.     

双功能磺酰胺的合成及不对称催化羟醛缩合反应研究

合成了一系列单磺酰化手性二胺,并用于催化丙酮与对硝基苯甲醛的不对称羟醛缩合反应。研究了手性二胺以及磺酰基结构对反应的影响,也研究了添加剂对反应的影响。对催化剂进行筛选,发现对硝基苯磺酰基取代的(1 S,2 S)-1,2-二苯基乙二胺为最佳催化剂,采用苯甲酸作为添加剂,反应可取得中等收率与对映选择性。     

催化不对称烷基化反应中氨基醇配体研究进展

二烷基锌对醛的不对称加成反应是合成手性二级醇的有效方法,反应产物手性二级醇是药物、精细化学品、天然产物的重要中间体,手性氨基醇是诱导这类反应手性配体的重要组成部分并且表现出了很高的对映选择性。综述了催化该类反应手性氨基醇配体的一些研究新进展。     

Enantioselective Construction of the Biologically Significant Dibenzo[1,4]diazepine Scaffold via Organocatalytic Asymmetric Three‐Component Reactions

The first catalytic asymmetric construction of the biologically important dibenzo[1,4]diazepine scaffold has been established via SPINOL‐derived chiral phosphoric acid‐catalyzed three‐component reactions of aldehydes, 1,2‐phenylenediamines and cyclohexane‐1,3‐diones, which afforded structurally complex and diverse dibenzo[1,4]diazepines in high yields and good enantioselectivities (up to 98% yield, 92:8 er). This transformation also represents the first catalytic asymmetric version of this three‐component reaction and provides an easy access to structurally rigid seven‐membered chiral heterocycles.

     

金属络合物不对称催化硫醚氧化研究现状

手性亚砜是重要的手性中间体和辅剂、手性配体和催化剂、手性药物。手性金属络合物催化硫醚的不对称氧化是合成手性亚砜最有效的方法。文章简要的介绍了钛,钒,铌,铁四种金属的络合物不对称催化硫醚氧化的一些最新的研究现状。     

Asymmetric Sulfoxidation of Thioethers with Hydrogen Peroxide in Water Mediated by Platinum Chiral Catalyst

Easy stereoselective oxidation of prochiral aryl alkyl sulfides 2 to the corresponding sulfoxides can be achieved in water‐surfactant medium with inexpensive hydrogen peroxide mediated by the chiral platinum diphosphine complex {[(R)‐BINAP]Pt(μ‐OH)}₂(BF₄)₂ ( 1 ). Remarkable key features of general interest are (i) easy isolation of the products from catalyst by simple diethyl ether/water‐surfactant two phase separation, (ii) catalyst loading as low as 1% mol, (iii) good yields, sulfoxide 3 to sulfone 4 ratio up to 200 : 1 and enantioselectivities up to 88%, (iv) mild experimental conditions.     

A New Enantioselective Synthesis of Milnacipran and an Analogue by Catalytic Asymmetric Cyclopropanation

Milnacipran and analogues are conveniently prepared by a short sequence of steps from phenylacetic acid, the key step being highly enantioselective catalytic asymmetric cyclopropanation.     

手性金属Salen-Mn络合物在不对称环氧化反应中的应用

手性salen金属络合物在烯丙醇类化合物的动力学拆分,环氧化合物的不对称开环以及非官能化烯烃的不对称环氧化等反应中已得到了广泛的应用。本文主要介绍了手性金属salen-Mn络合物在非官能化烯烃的不对称环氧化反应中取得的新进展。     

不对称催化反应合成手性药物的研究进展

综述了不对称催化反应在手性药物合成中的应用,包括不对称催化氢化、不对称催化氧化、不对称催化环丙烷化、不对称催化羰基化和羰基的不对称催化还原。介绍了L-多巴、(S)-萘普生、薄荷醇、(S)-心得安、(S)-阿替洛尔、二肽抑制剂Cilastatin、氟西汀、布洛芬的合成工艺和Sharpless环氧化(AE反应)、不对称双羟基化(AD反应)、不对称羟氨化(AA反应)三种典型的不对称催化氧化反应。展望了不对称催化反应在手性药物合成中的发展方向。     

手性BINOL磷酸催化剂在不对称转化中的应用

3,3＇-位基团取代手性BINOL磷酸在不对称催化反应中具有较强的催化活性。其原因在于：（1）手性BINOL磷酸具有较强的（P=O）Lewis碱和较强的（P-OH）Lewis酸,可以有效通过与催化底物之间形成氢键,激活反应体系;（2）在手性BINOL磷酸的3,3＇-位上引入阻位基团,建立有效的手性环境,可以成功地诱导不对称转化。本文例举了通过氢键相互作用,手性BINOL磷酸催化剂成功地诱导不对称催化反应。     

烯烃不对称环氧化反应催化剂的研究进展

综述了手性催化剂催化的不对称环氧化反应研究进展情况。     

Catalytic Asymmetric Synthesis of Chiral Benzofuranones

The chiral benzofuranone structural motif is a prominent feature in many natural products, which exhibit a broad range of biological and pharmaceutical activities. In the past few years, a survey of chiral benzofuranone derivatives based on asymmetric catalysis reveals an increasing number of papers, which reflects the latest achievements to facilitate the synthesis of sufficient quantities of related compounds as potential medicinal agents and biological probes. Recent advances in this area are summarized and classified according to the structure of the starting substrate.

     

Asymmetric oxidation of sulfides

This review discusses synthesis of enantiopure sulfoxides through the asymmetric oxidation of prochiral sulfides. The use of metal complexes to promote asymmetric sulfoxidation is described in detail, with a particular emphasis on the synthesis of biologically active sulfoxides. The use of non-metal-based systems, such as oxaziridines, chiral hydroperoxides and peracids, as well as enzyme-catalyzed sulfoxidations is also examined.     

Vanadium‐Catalyzed Enantioselective Sulfoxidation and Concomitant,Highly Efficient Kinetic Resolution Provide High Enantioselectivity and Acceptable Yields of Sulfoxides

Simple, inexpensive, preformed vanadium‐Schiff base complexes were facilely prepared and used in enantioselective sulfoxidation. Both the amount of aqueous H₂O₂ and reaction time greatly influenced the ee values and yields of chiral sulfoxides. High enantioselectivities (up to 99% ee) and reasonable yields (>40%) for various chiral sulfoxides were achieved by combining enantioselective sulfoxidation and appropriate concomitant kinetic resolution.     

A Highly Active 4‐Siloxyproline Catalyst for Asymmetric Synthesis

trans‐4‐tert‐Butyldimethylsiloxy‐L ‐proline displays a greater catalytic activity than the parent proline without compromising the enantioselectivity, which widens the substrate scope in the α‐aminoxylation of carbonyl compounds, as well as O‐nitroso‐aldol/Michael, and Mannich reactions.     

Chiral Phosphoric Acid‐Catalyzed Asymmetric Oxidation of Aryl Alkyl Sulfides and Aldehyde‐Derived 1,3‐Dithianes: Using Aqueous Hydrogen Peroxide as the Terminal Oxidant

(R)‐1,1′‐Binaphthyl‐2,2′‐diol (R‐BINOL) derived chiral phosphoric acids have been explored as organocatalysts for the asymmetric oxidation of a series of aryl alkyl sulfides and 1,3‐dithianes derived from aldehydes with aqueous hydrogen peroxide (H₂O₂) as the terminal oxidant. The enantiomerically enriched sulfoxides are obtained in moderate to excellent yield (up to 99%) with excellent diastereoselectivity (up to >99:1 dr) and moderate to good enantioselectivity (up to 91:9 er). In particular, the present protocol stereoselectively provides an efficient access to enantiomerically enriched aryl alkyl sulfoxides and dithioacetal mono‐sulfoxides, which strictly restrains the formation of the undesirable by‐products: sulfones or disulfoxides. The tracking experiments also verify that this approach proceeds via a direct sulfoxidation process, instead of a kinetic resolution route by overoxidation of the resulting sulfoxides.     

Modular Synthesis of Ar‐BINMOL‐Phos for Catalytic Asymmetric Alkynylation of Aromatic Aldehydes with Unexpected Reversal of Enantioselectivity

An interesting group of multifunctional phosphines (Ar‐BINMOL‐Phos; Ar‐BINMOL=1,1′‐binaphthalene‐2‐α‐arylmethanol‐2′‐ol) with multi‐stereogenic centers of axial and sp³‐central chirality has been prepared successfully from a single chiral source through a concise synthetic route, in which the neighbouring lithium‐promoted [1,2]‐Wittig rearrangement proceeding with excellent diastereoselectivity and enantioselectivity is the key process in this approach. Also, in the catalytic alkynylation of aromatic aldehydes with terminal alkynes, the combination of these Ar‐BINMOL‐Phos ligands with dimethylzinc was found to be an effective catalyst system to afford predominantly the S‐configured propargylic alcohols, whereas the additional use of calcium hydride and n‐butyllithium along with the same Ar‐BINMOL‐Phos ligands gave the R‐configured products in high yields and excellent enantioselectivities (up to >99% ee).