有机催化苯并三氮唑与查耳酮的不对称aza-Michael加成反应

将脯氨醇衍生物用于有机催化苯并三氮唑与查耳酮的不对称aza-Michael加成反应,制备手性氮杂环化合物。通过~1HNMR、~(13)CNMR和HR-MS光谱技术对其结构进行表征,通过HPLC手性色谱柱测定产品的对映体过量值(e.e.)。考察溶剂、温度及催化剂用量对反应立体选择性的影响,进而优化催化剂体系。结果表明,最佳催化条件为20 mol%催化剂,甲苯为溶剂,0℃下反应。将此条件用于7种不同取代查耳酮的反应,得到了58%~70%的收率和最高达72%的对映选择性,拓宽了该反应的催化剂类型和底物范围。     

手性方酰胺催化迈克尔加成反应合成1,4-萘醌衍生物的研究

以奎宁和方酸二乙酯为主要原料制备了手性方酰胺催化剂1,研究了催化剂1对指甲花醌和β-硝基苯乙烯反应合成1,4-萘醌衍生物的催化性能。催化剂1和衍1,4-萘醌衍生物的结构经~1 HNMR和~(13)CNMR确证,并对反应采用的溶剂、物料比、反应温度、催化剂用量进行了考察,在最佳的反应条件下,1,4-萘醌衍生物的收率为95.24%,对映体选择性(ee值)为61.18%。     

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。     

双官能团硫脲-胺催化剂催化不对称有机反应的研究进展

双官能团硫脲-胺催化剂因在不对称催化反应中表现出的高效、高对映选择性而受到广泛关注,已成功应用于催化各种不对称有机反应中,本文简述了双官能团硫脲-胺催化剂在Michael加成、1,2加成以及Michael-type串联反应中应用的研究进展。     

手性3,3-二取代氧化吲哚衍生物及其合成方法和应用

<正>本发明涉及一种具有PTP1B抑制作用的新型的手性3,3-二取代氧化吲哚衍生物的化学合成方法。本发明以重氮靛红、吲哚、芳胺和醛酸酯为原料,以金属催化剂为催化剂,以手性磷酸为共催化剂,以有机溶剂为溶剂,以分子筛为添加剂,在25℃条件下经过一步反应,柱层析提纯即得到产物。本发明具有步骤经济性、原子经济性、非对映选择性和对映选     

脂肪酶催化动力学拆分大分子手性化合物的研究进展

脂肪酶已广泛用于制备手性化合物的动力学拆分中,但大多数酶催化拆分外消旋化合物,特别是大分子手性化合物的对映选择性不很理想。目前,提高脂肪酶对映选择性的研究主要在改造脂肪酶蛋白结构、优化体系的反应条件、改善反应过程以及对映选择性抑制等方面进行。本文主要介绍了几种改善脂肪酶催化动力学拆分大分子手性化合物对映选择性的合理方法。     

3,3’-位杂原子取代的BINOL类手性催化剂在不对称合成中的应用

从一系列3,3’-位杂原子取代的BINOL（1,1’-联二萘酚）类手性催化剂不对称催化反应类型的不同,探讨了3,3’-位杂原子取代的BINOL类手性催化剂在不对称合成中应用的研究进展,指出3,3’-位杂原子取代的BINOL类手性催化剂不对称催化底物高效的对映体选择性,并对该类手性催化剂的发展进行了展望。     

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。     

金属催化制备手性胺的研究新进展

手性胺化合物广泛存在于自然界中并扮演着重要的角色,亚胺的不对称催化还原反应是制备手性胺化合物的最直接有效的方法。金属钯、钴、铜、铼和锌作为亚胺不对称还原的新型催化剂是最近几年发展起来的,在底物普适性和产物对映选择性方面取得了很大的进展。综述了这五种金属催化体系在制备手性胺中的研究进展和存在的问题,总结了每一催化体系的优缺点。     

Highly Enantioselective Michael Addition of Cyclic 1,3‐Dicarbonyl Compounds to β,γ‐Unsaturated α‐Keto Esters

A highly enantioselective Michael addition of cyclic 1,3‐dicarbonyl compounds to β,γ‐unsaturated α‐keto esters catalyzed by amino acid‐derived thiourea‐tertiary‐amine catalysts is presented. Using 5 mol% of a novel tyrosine‐derived thiourea catalyst, a series of chiral coumarin derivatives were obtained in excellent yields (up to 99%) and with up to 96% ee under very mild conditions within a short reaction time.     

[2.2]Paracyclophane-Derived Planar-Chiral Hydrogen-Bond Receptors

The development of planar-chiral hydrogen-bond donors based on the [2.2]paracyclophane scaffold is discussed. General strategies to access functionalized enantiopure [2.2]paracyclophane derivatives are briefly reviewed, with the focus on suitable precursors for the synthesis of planar-chiral thiourea derivatives. The synthesis of fourteen hydrogen-bond donors is described. The interaction of four thiourea derivatives with hydrogen-bond acceptors (DMSO and tetramethylammonium chloride) was investigated by ¹H NMR spectroscopy and X-ray crystallography. A selection of enantiomerically pure planar-chiral derivatives was applied in asymmetric hydrogen-bond catalysis.     

Highly Enantioselective Michael Addition Reactions of 3‐Substituted Benzofuran‐2(3H)‐ones to Chalcones Catalyzed by a Chiral Alkyl‐Substituted Thiourea

A highly enantioselective Michael addition of 3‐substituted benzofuran‐2(3H)‐ones to chalcones catalyzed by a chiral bifunctional thiourea was developed. Several chiral 3,3′‐substituted benzofuran‐2(3H)‐ones derivatives, bearing adjacent quaternary‐tertiary stereocenters, were efficiently synthesized with excellent enantioselectivities.     

论氧气法制胍衍生物的化学反应

通过对硫脲衍生物分子化学键的研究，发现了氧气法不仅适用于生产二苯胍，还适用于生产其他胍衍生物。就是说，硫脲衍生物可以通过氧气法制成相应的胍衍生物。氧气法生产胍衍生物的化学反应过程中，铜离子的催化作用发生在硫脲衍生物与氧气进行反应生成二氧化硫脲衍生物的反应阶段。铜离子的催化作用表现为消除硫脲衍生物分子母体的共轭π键，使硫基π键孤离出来，并使硫基极化。本文讨论硫脲衍生物分子母体的化学键及其变化，叙述氧气法制胍衍生物的化学反应。     

The enantioselective synthesis of alpha-amino acids by phase-transfer catalysis with achiral Schiff base esters

The development and application of chiral phase-transfer catalysis (PTC) for the enantioselective synthesis of optically active alpha-amino acid derivatives using achiral Schiff base esters developed in the author's laboratory and by others is reviewed. Phase-transfer catalysts derived from the Cinchona alkaloids have been exploited as inexpensive and attractive organocatalysts in the chiral PTC process. The recent evolution and use of these and other catalytic systems is described.     

Fundamental Investigations of Enantioselective Heterogeneous Catalysis

Enantioselective heterogeneous catalysis is an important and rapidly expanding research area. The two most heavily researched examples of this type of catalysis are the enantioselective hydrogenation of α-ketoesters over Pt-based catalysts and the enantioselective hydrogenation of β-ketoesters over Ni-based catalysts. These systems share one extremely important common feature—the enantioselective surface reaction is controlled by the presence of adsorbed chiral molecules (modifiers) on the surface of the metal component of the catalyst. In each system, a number of models have been proposed to explain the enantioselective behavior in the light of catalytic experiments. In recent years, surface science has begun to address the issues relevant to this branch of catalysis. This article reviews to what extent surface science has enabled the verification of the proposed models and, in addition, what new light surface science has shed on the possible mechanisms of enantioselective heterogeneous catalysis.     

Organocatalytic Asymmetric Michael Addition of Pyrazolin‐5‐ones to Nitroolefins with Bifunctional Thiourea: Stereocontrolled Construction of Contiguous Quaternary and Tertiary Stereocenters

The first organocatalytic diastereo‐ and enantioselective Michael addition reaction of 4‐substituted‐pyrazolin‐5‐ones to nitroolefins has been developed with a chiral bifunctional thiourea as organocatalyst. A wide variety of desired multi‐substituted pyrazolin‐5‐one derivatives with contiguous quaternary and tertiary stereocenters are smoothly obtained in very good yields (up to 98%) with excellent enantioselectivities (up to>99% ee) and acceptable diastereoselectivities (up to 80:20). This experimentally simple process facilitates the access to various enantioenriched, multiply substituted pyrazolin‐5‐one derivatives, potential biologically active molecules, starting from readily available starting materials.     

Kinetic resolution of terminal epoxides with phenols promoted by heterometallic Co–Al and Co–Ga salen complexes

The binuclear chiral (salen) Co complexes bearing Lewis acid salt (Al and Ga) and 4-nitrobenzene sulfonic acid (NBS) catalyze the enantioselective ring opening of terminal epoxides with phenol derivatives. The easily prepared complexes exhibited very high catalytic reactivity and enantioselectivity for the asymmetric ring opening of terminal epoxides with phenol and consequently provide enantiomerically enriched corresponding α-aryloxy alcohols (up to >99% ee). The two unit of salen complexes combined by Lewis acid exhibited co-operative catalysis during the ring opening reaction.     

Asymmetric Organocatalytic Cascade Michael/Michael/Henry Reaction Sequence: Control of All Stereocenters in One Cyclohexane Skeleton

The highly diastereo‐ and enantioselective relay cascade Michael/Michael/Henry reaction catalyzed by combination of readily available diphenylprolinol silyl ether and the quinine thiourea in a one‐pot fashion has been developed. Up to 70% yield and up to >99% enantioselectivity of the single major isomer were obtained from the cascade reactions.     

Rapid and highly efficient synthesis of thioureas in biocompatible basic choline hydroxide

A straightforward and convenient synthesis of symmetrical thiourea derivatives by the reaction of primary amines and carbon disulfide in biocompatible basic choline hydroxide is presented. A variety of biologically important thiourea derivatives can be obtained in good to excellent yields without a tedious work-up under mild reaction conditions. A series of primary aliphatic and aromatic amines with different substituted functional groups have been converted to thiourea derivatives under milder reaction conditions and short reaction times.