New Chiral Ligand N-Toluenesulfonyl-2,2′-dimethoxy-6,6′-diaminobiphenyl for Catalytic Asymmetric Transfer Hydrogenation of Ketones

A new chiral ligand N p toluenesulfonyl 2,2′ dimethoxy 6,6′ diaminobiphenyl (Ts DMBDPPA) was prepared from 2,2′ dimethoxy 6,6′ diaminobiphenyl via N tosylation. Its Ru(II) complex was effective catalysts for catalytic asymmetric transfer hydrogenation of aromatic ketones (with ee 's up to 69.3%).

Axially Dissymmetric Chiral (R)-N,N′-Bis(2-hydroxy-3,5-di-tert-butyl-arylmethyl)-1,1′-binaphthalene-2,2′-diamine as Chiral Ligands in the Reaction of Diethylzinc to Aldehydes

Chiral ligand (R)-N, N'-Bis(2-hydroxy-3,5-di- tert-butyl-aryl-methyl)-1, 1'-binaphthalene-2,2'-diamine derived from the reduction of Schiff base (R)-2,2'-bis (3,5-di-tert-butyl-2-hy-droxybenzylideneamino)-1, 1'-binaphthyl with LiAIH(4) is fairly effective in the asymmetric addition reaction of diethylzinc to aldehydes by which good yields (46%-94%) of the corresponding sec-alcohols can be obtained in moderate ee (51%-79%) with R configuration for a variety of aldehydes.

Asymmetric Reformatsky Reaction Induced by Dipeptides

For the first time, synthetic dipeptides were applied to the catalysis of asymmetric Reformatsky reaction. Review in this domain & factors influencing enantioselectivity were discussed.

Ruthenium-Catalysed Asymmetric Intramolecular Isomerization/Esterification Reaction: Direct Synthesis of Chiral Dihydrocoumarins

An asymmetric isomerization/intramolecular coupling reaction of allylic alcohols to synthesize chiral dihydrocoumarins was successfully accomplished through ruthenium catalysis.This method demonstrates a wide substrate applicability,excellent tolerance for various functional groups,and good enantioselectivities(up to 90%ee).It provides a convenient pathway to produce a diverse range ofstructurallydistinct chiral dihydrocoumarins ingoodefficiency.

Catalytic asymmetric dearomative azo-Diels–Alder reaction of 2-vinlyindoles

Due to the high electrophilic nature of azo-dienophiles, azo-Diels–Alder proceeds rapidly even without the need of a catalyst and is therefore regarded as the “click reaction”. This spontaneity causes strong background reaction and poses a daunting challenge to chemists for developing the catalytic asymmetric version. Reported herein is the first catalytic asymmetric dearomative azo-Diels–Alder reaction between2-vinylindoles and triazoledione. This protocol makes use of the high energy barrier of dearomatization to avert the strong background reaction of azo-Diels–Alder reaction, allowing the implementation of the projected reaction at ambient temperature. Density functional theory calculations have been performed to gain insights into the reaction mechanism and the origins of the enantioselectivity. By using this method,a variety of tetracyclic indole derivatives have been readily prepared in good to excellent yields and with excellent diastereo-and enantio–selectivities(33 examples, up to 97% yield and >99% ee, >20:1 dr).

Enantioselective Addition of Diethylzinc to Benzaldehyde by Catalysts of Chiral Heterocyclic Ligands

Several kinds of chiral heterocyclic ligands without hydroxyl group have been synthesized and used as catalysts for the asymmetric addition of diethylzinc to benzaldehyde. These ligands promoted the formation of (S)-1-phenylpropanols in good yields and medium to good enantioselectivities (50 similar to 86 % ee.).

Construction of axially chiral compounds via catalytic asymmetric radical reaction

The chemistry of axially chiral compounds has emerged as a subject of increasing interest due to their widespread presence in natural products,bioactive molecules,advanced materials,and chiral ligands/catalysts.On the other hand,catalytic asymmetric radical-based transformations provide a complementary platform for the construction of enantiomerically enriched molecules that are in growing demand in the chemical and pharmaceutical in-dustries.In recent years,considerable research efforts have been devoted to the development of catalytic asymmetric radical reactions for the construction of axially chiral compounds based on the unique reactivity modes of diverse radicals.In this review,we critically illustrate these recent achievements according to different radical precursors and catalytic activation modes.Wherever possible,special emphasis is also placed on the discussion of mechanistic features underlying these works and substrate scopes.This review should be of great interest to the experts in this area,but also serve as a helpful starting point for new researchers in this field.

铑−单膦催化剂在不对称氢化反应中的研究进展

不对称氢化反应凭借良好的原子经济性、立体选择性和环境效益等优点在有机合成化学领域占有重要地位.不对称催化氢化反应研究的核心内容是手性配体和手性催化剂,其中过渡金属中的铑表现出催化活性高、化学性质稳定等优异性能,以及手性单齿膦配体具有合成方法简便、原料易得等优点,使得铑−单膦催化剂在不对称氢化反应中得到广泛应用.基于此,开发新型、催化效率高的手性单膦配体及铑催化剂仍是一个不断发展的领域.以铑催化不对称氢化反应为核心,手性单齿膦配体的发展为主线,作者详细介绍了反应过程中涉及到的手性单齿膦配体、底物结构、反应条件和产物的对映选择性等,以期对铑−单膦催化剂在不对称氢化反应中的应用有深入理解.

Chiral Imidazoline Ligands and Their Applications in Metal-Catalyzed Asymmetric Synthesis

As a structural analog of oxazoline,imidazoline(4,5-dihydroimidazole)has received much attention in the rational design of chiral ligands.The additional N-substituent provides broader space for fine-tuning of electronic and steric effects,and it offers a good handle for immobilizing onto solid supports.In the past decades,imidazoline ring has emerged as a powerful candidate for the design of chiral nitrogen-containing ligands,as well as a significant alternative for oxazoline ring.Various chiral imidazoline ligands have been designed and utilized in asymmetric organic reactions.These new catalysts can not only be applied in classical reactions,but also be employed to develop new organic reactions with high enantioselectivities.This review provides an overview of chiral imidazoline ligands.Their applications in asymmetric synthesis are also summarized.

Efficient P-Chiral Biaryl Bisphosphorus Ligands for Palladium-Catalyzed Asymmetric Hydrogenation

A series of structurally novel P-chiral biaryl bisphosphorus ligands L1-L5 （BABIBOPs） are developed, providing high efficiency for the first time in palladium-catalyzed asymmetric hydrogenation of β-aryl and β-alkyl substituted β-keto esters. With the Pd-1.3 （iPr-BABIBOP） catalyst, a series of chiral β-hydroxyl carboxylic esters are formed in excellent enantioselectivities （up to 〉 99% ee） and yields at catalyst loading as low as 0.01 mol%.

氨甲基树脂固载手性双烯配体-铑催化剂的制备及催化不对称1,4加成反应的研究

从(R)-α-水芹烯和丙炔酸甲酯开始合成手性双烯配体,再与氨甲基(AM)树脂反应并络合铑得到固载铑的催化剂。用得到的固载催化剂进行一系列α,β不饱和酮与苯硼酸的不对称1,4加成反应。研究结果表明,合成的固载化催化剂参与的反应在温和的反应条件下产率为70%~80%,ee为70%~90%,而且合成的固载化铑催化剂具有很好的重复利用性。

新型手性辅剂N-甲基苯丙胺醇诱导不对称Michael加成反应研究

新型手性辅助剂是Michael加成反应体系中一类重要的催化剂,可实现高立体选择性的Michael加成反应。本论文以苯丙氨酸制备的手性N-甲基苯丙胺醇作为手性辅剂,通过其与溴代芳基醛形成四氢噁唑芳基锂试剂,然后对烷基的α,β-不饱和叔丁酯类化合物(1-环戊烯甲酸叔丁酯和1-环己烯甲酸叔丁酯受体)进行了不对称共轭加成反应研究。本方法成功制备了ee值为90%~95%和产率为35%~55%的加成产物(6/7/6a/6b/7a/7b)。

Design, Synthesis and Application of Multifunctional Chiral Aminophosphine Catalyst for Asymmetric Intermolecular Cross Rauhut-Currier Reaction

A series of structurally novel multifunctional chiral aminophosphine catalysts were developed through a concise synthetic strategy from easily available starting materials.The highly enantioselective intermolecular cross Rauhut-Currier reactions of vinyl ketones with 3-acyl acrylates and 2-ene-1,4-diones catalyzed by(S,S)-5a were well realized,generating a wide range of the structurally important chiral multicarbonyl products in good to excellent yields with high stereocontrol(up to 97%yield,99%ee).In addition,a series of 31P NMR experiments were carried out to further investigate the catalytic process.

手性药物技术与展望

在 2 0世纪有机化学的发展中 ,最重要的突破之一是不对称催化反应的研究成功 ,它作为手性技术应用于合成工业 ,尤其是涉及到人类健康的巨大市场而崛起的高科技产业———手性药物 ,倍受关注 .本文综述了对手性药物的认识和发展 ,并且参考最新文献和作者近期的研究工作 。

手性季铵盐类相转移催化剂的新进展

叙述了手性季铵盐类相转移催化剂在不对称催化反应 (包括活性亚甲基的烷基化、Michael加成、双键的环氧化、Darzens缩合、氮杂环丙烷的合成、羟醛缩合以及Horner Wadsworth Emmons反应 )中应用的新进展 .

手性二茂铁膦配体在不对称催化反应中的应用

综述了手性二茂铁膦配体的过渡金属配合物催化不对称氢化、硅氢化、交叉偶联、环加成、Aldol等反应的最新进展 ,参考文献 5 6篇。

手性Salen-Cu(Ⅱ)和噁唑啉-Cu(Ⅱ)配合物催化2-苯基环己酮的不对称Baeyer-Villiger反应研究

对一系列手性Salen和唑啉配体与中心金属Cu(Ⅱ )的配合物催化 2 苯基环己酮的不对称Baeyer Villiger反应进行了研究 ,设计和合成了新型手性配体Ⅲ ,Ⅳ ,Ⅴ ,对配合物Ⅴ Cu(Ⅱ )进行了单晶X射线衍射分析 .并考察了助氧化剂、溶剂等对反应活性和选择性的影响 .

具有C_2对称轴的手性配体及其不对称催化反应

按配位原子的数目进行分类，综述了近年来研究较多的具有Ｃ_２对称轴的手性配体及其相关的不对称催化反应，并对该类手性配体的设计做了分析和总结。参考文献７９篇。

催化不对称Michael加成反应的新进展

总结了近年催化不对称Michael加成反应的新方法 ,包括手性金属络合物催化的反应 ,呈手性Lewis酸性的手性金属络合物促进的不对称加成 。