钌-手性膦配体催化剂在不对称催化氢化反应中的应用

较详细的综述了钌-手性膦配体催化剂在不对称催化氢化反应中的最新应用进展，主要从钌-手性膦配体催化剂在芳基丙烯酸(萘普生、布洛芬等)、酰胺类化合物、酮酯等方面的不对称催化反应中的应用进行综述，文章从催化剂活性、立体选择性、转化率和对映选择性等角度讨论了各种合成方法的优点及不足。     

兰化所高效手性催化剂开发取得进展

中科院兰州化学物理研究所日前在芳酮不对称氢化反应的催化剂制备研究中取得突破,研究人员首次将非手性膦与自行设计合成的刚性手性环状二双胺结合,制得一种新型手性钌催化剂,并将其成功应用于芳酮不对称氢化反应,得到了极高的对映选择性和反应活性。该研究成果将大大促进简单而实用的经济型双膦配体在酮类对映选择性氢化反应     

(R)-BINOL制备的手性磷酸在不对称Mannich反应中的应用

手性磷酸是本世纪初发展起来的一种新型有机小分子催化剂,其拥有一个Brnsted酸酸性位点和一个Lewis碱碱性位点,由于其酸性位点适宜的酸性,可向一些反应分子提供质子或与其形成氢键的弱相互作用,而碱性位点的磷氧双键可以提供孤对电子,因此手性磷酸具有双功能催化剂的优点,促使其在有机不对称反应中显示出独特的催化活性以及较高的对映选择性,特别在催化亚胺的反应中,更显示出特别高的催化效能。针对手性磷酸在不对称Mannich反应中的应用进展及其不对称催化作用机理进行综述,并对该类应用未来的发展方向做了一定的预测与展望。     

不对称催化制备手性苯并磺内酰胺的研究进展

手性苯并磺内酰胺类化合物广泛存在于各种药物结构和天然产物中,是抗菌、抗肿瘤、抗病毒等药物的重要组成部分。有机小分子催化剂和有机金属配合物催化剂的发展,使催化不对称合成手性苯并磺内酰胺领域涌现大量研究成果。综述了手性苯并磺内酰胺的不对称催化合成方法进展,包括不对称氢化还原、有机硼试剂不对称加成、不对称傅克反应和不对称曼尼希反应等反应类型,并重点阐述了不同类型的手性催化剂或手性配体对反应产率和对映选择性的影响。     

钛催化的不对称硫醚氧化研究进展

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.手性亚砜可以采用生物方法和化学方法来合成,化学方法包括手性辅剂诱导、手性氧化剂氧化、手性拆分和不对称催化等.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.理性设计各种手性金属络合物催化剂应用于催化对映选择性氧化潜手性硫醚反应中,近年来引起了化学家们较大的关注.作者简要综述了钛络合物催化剂在不对称硫醚氧化反应制备手性亚砜中的应用.     

不对称催化合成手性泛解酸内酯的研究进展

泛解酸内酯是合成D-泛酸钙和D-泛醇的重要中间体,国内主要采用生物拆分法,虽取得一定进展,但存在底物浓度偏低、反应条件苛刻、光学纯度不高和催化剂活性不强等问题。化学不对称合成法成为近年来制备手性泛内酯的研究热点。根据手性源的不同,介绍过渡金属配合物催化不对称还原酮基泛内酯,过渡金属配合物催化羟醛缩合反应,有机小分子及其衍生物不对称催化羟醛缩合反应并经还原内酯化合成泛内酯以及光学活性化合物作为反应底物或非手性底物中加入手性助剂的合成手性泛内酯工艺。其中,有机小分子催化乙醛酸酯与醛的反应表现出良好的催化效果,且催化剂易得,反应条件温和,操作简单。缩合产物的收率和对映选择性均不高,设计具有高活性和高选择性的有机小分子手性催化剂是今后研究的重点。     

有机小分子催化α，β-不饱和酮的不对称共轭加成反应研究进展

不饱和酮的不对称共轭加成反应在有机合成中是一类连接C-C键的非常重要的反应。相比过渡金属催化,有机小分子催化剂有着独特的优势,如不含过渡金属、容易制备、价格低廉、反应条件温和以及稳定性强等。文章综述了几类有机小分子催化剂对α,β-不饱和酮的不对称共轭加成反应。结果表明,手性胺和手性磷酸催化剂在不对称加成中具有良好的收率及选择性,但是包含联萘酚骨架的催化剂对于大部分的共轭加成反应均具有优秀的催化作用以及优异的选择性。     

聚合物负载手性催化剂在不对称合成中的应用

综述了近期聚合物负载手性催化剂在碳－碳键对映选择性的形成、有对称氧化反应和不对称还原反应方面应用的新进展。     

手性二烯配体的合成及其应用

随着不对称催化合成的发展,手性双烯配体得到快速的成长。与传统的手性配体相比,手性双烯配体在许多过渡金属化的不对称反应中体现出了更好的反应活性和立体选择性。本论文主要设计并改进了新型手性双烯配体的设计合成。     

金属卟啉催化烯烃不对称环氧化反应的研究

合成了5种简单金属卟啉锰配合物，并以这5种金属卟啉作为催化剂，以手性季铵盐为手性相转移催化剂，研究催化烯烃不对称环氧化反应。结果表明：金属卟啉锰中苯环上的不同取代基对烯烃环氧化速度有较大的影响；手性相转移催化剂的加入，不仅提高了反应速度，而且对烯烃的环氧化起到了一定的不对称诱导作用；不同底物的烯烃，不对称环氧化反应对映选择性不同。     

Reduced graphene oxide supported chiral Ni particles as magnetically reusable and enantioselective catalyst for asymmetric hydrogenation

A reduced graphene oxide (rGO) supported chiral-modified Ni catalyst was synthesized, characterized and employed for asymmetric hydrogenation. The prepared hybrid catalyst could produce each enantiomer with d- or l-tartaric acid as chiral modifier and exhibited a high TOF (20160 h⁻¹) and enantioselectivity (enantiomeric excess, 98.5%) for asymmetric hydrogenation of methyl acetoacetate. The high catalytic activity and enantioselectivity were mainly attributed to the unique properties of the support rGO, as it had a large specific surface area to sustain and stabilize Ni particles and its high charge carrier mobility could enable the readily transfer of electrons in the reaction process. Besides, the catalyst could also gain an enhanced reactant sorption with the support of rGO, thus achieved a greatly catalysis enhancement. The ferromagnetism of Ni made the catalyst easier for separation and reuse. The catalytic and recycling performance of the prepared chiral Ni catalyst demonstrated that rGO was indeed a promising support to improve activity, enantioselectivity and durability of catalysts, and the prepared catalysts were promising reusable heterogeneous catalysts for asymmetric hydrogenation.     

Asymmetric transfer hydrogenation of ketones catalyzed by thermoregulated ionic liquid-regulating ruthenium complexes

A sulfonated chiral diamine ligand anion-based functionalized ionic liquid has been synthesized. Then the new ionic liquid-regulating ruthenium complexes were prepared successfully and employed as efficient catalysts for the asymmetric transfer hydrogenation of various ketones. The catalysts were highly efficient for the hydrogenation of a wide range of substrates bearing different functional groups and could be separated easily from the reaction mixture by thermoregulated phase separation, which can be efficiently recycled five times without significant changes in catalytic activity and enantioselectivity.     

铑催化剂催化烯烃不对称加氢反应研究进展

不对称催化氢化反应具有完美的原子经济性和清洁高效等特点,是最受青睐的不对称合成方法之一。C=C、C=O、C=N的不对称加氢反应仍主要依赖过渡金属催化剂。过渡金属催化剂,尤其是铑催化剂,催化碳碳双键的不对称加氢反应仍是一个不断发展的领域。本文对近年来利用铑催化剂催化烯烃进行不对称氢化反应的研究进展进行了综述,着重介绍了铑-双膦配体催化体系催化烯烃不对称加氢反应的催化机理,以及铑催化剂在烯胺、不饱和羧酸及衍生物、烯醇酯和非官能团烯烃不对称氢化中的应用,并通过对现有文献的总结指出了今后铑催化剂催化烯烃氢化反应的研究重点,即:①铑-单膦配体催化烯烃不对称氢化反应的作用机理须待提出;②非官能化底物不对称催化氢化反应的手性配体亟待拓宽。     

Self-supported chiral catalysts for heterogeneous asymmetric catalysis

A conceptually new strategy for chiral catalyst immobilization, self-supported catalysts, in heterogeneous asymmetric catalysis is highlighted in the present article. Various homochiral metal-organic polymers with diverse structures have been designed and readily prepared through coordination assembly of modular polytypic/polyfunctional ligands and metal ions without using any supports. These polymers have been successfully employed as chiral catalysts in a variety of heterogeneous asymmetric ractions, including hydrogenation, epoxidation, sulfoxidation, carbonyl-ene reactions, diethylzinc addition, and Michael addition. The self-supported heterogeneous chiral catalysts showed activity and enanioselectivity comparable or even superior to those obtained with their corresponding homogeneous counterparts, and could be readily recovered and reused several times without significant loss of activity or enantioslectivity.     

Preparation of microgel-supported chiral catalysts and their application in the asymmetric hydrogenation of aromatic ketones

An enantiomerically pure chiral monomer (S,S)-2 was prepared and copolymerized with styrene and four different cross-linkers to produce four distinct microgel-supported chiral TsDPEN derivatives. These chiral copolymers were allowed to form complexes with [RuCl₂(cymene)]₂ and the resulting homogeneous catalysts were applied in asymmetric hydrogenation reactions of aromatic ketones to give enantioenriched secondary alcohols in quantitative yield. These polymeric catalysts can be easily separated from the reaction mixture and recycled several times without a significant loss in catalytic activity.     

多相手性催化剂的制备及其对不对称加氢反应的催化作用

综述了不对称加氢反应中多相手性催化剂的研究进展,包括将均相手性催化剂固定到有机聚合物、磁性的Fe₃O₄纳米颗粒、功能化修饰的分子筛等载体上;直接利用有机金属配合物中的阳离子和分子筛骨架中的阴离子相互作用实现多相化;采用金鸡纳生物碱等手性小分子为修饰剂和天然高分子为手性源制备多相催化剂。同时对不同途径制备的多相手性催化剂的结构特性、催化性能和立体选择性进行了评价。     

Dendronized Poly(Ru‐BINAP) Complexes: Highly Effective and Easily Recyclable Catalysts For Asymmetric Hydrogenation

A new kind of dendronized polymeric chiral BINAP ligands has been synthesized and applied to the Ru‐catalyzed asymmetric hydrogenation of simple aryl ketones and 2‐arylacrylic acids. These dendronized poly(Ru‐BINAP) catalysts exhibited high catalytic activity and enantioselectivity, very similar to those obtained with the corresponding parent Ru(BINAP) and the Ru(BINAP)‐cored dendrimers. It was found that the pendant dendrons had a major impact on the solubility and the catalytic properties of the polymeric ligands. These polymeric catalysts could be easily recovered from the reaction solution by using solvent precipitation, and the reused catalyst showed no loss of activity or enantioselectivity.     

Asymmetric hydrogenation of heteroaromatic compounds

Asymmetric hydrogenation of heteroaromatic compounds has emerged as a promising new route to saturated or partially saturated chiral heterocyclic compounds. In this Account, we outline recent advances in asymmetric hydrogenation of heteroaromatic compounds, including indole, quinoline, isoquinoline, furan, and pyridine derivatives, using chiral organometallic catalysts and organocatalysts.     

Diastereoselective catalytic hydrogenation on heterogeneous metal catalysts

The application of diastereoselective hydrogenation catalyzed by heterogeneous catalysts for the asymmetric synthesis of organic compounds is illustrated in the reduction of several functional groups. In that approach, the chiral information is provided by the prior attachment of a chiral auxiliary to the substrate to be hydrogenated. The optically active hydrogenated product is then disconnected from the chiral auxiliary. Proper choice of the inductor, of the catalyst and of reaction conditions may result in high diastereoselectivities. This revised version was published online in June 2006 with corrections to the Cover Date.