Asymmetric Catalysis

不对称催化
  • 文章类型: Journal Article
    据报道,在镍催化下,苯酚与外消旋甲硅烷基化/发芽烯丙基氯化物的α-/γ-区域异构体混合物发生了对映体和区域会聚烯丙基化。甲硅烷基/甲苯基基团控制区域选择性,并且该转化提供了对映体富集的不对称的1,3-二取代的烯丙基芳基醚,具有良好的区域控制性,产率和出色的对映选择性。值得注意的是,在室温下没有观察到镍介导的C-O键活化。在一系列化学选择性转化中证明了这些致密功能化的含硅结构单元的合成价值,包括用于构建α-手性硅烷的[3,3]-sigmatchic重排。
    An enantio- and regioconvergent allylation of phenols under nickel catalysis with an α-/γ-regioisomeric mixture of racemic silylated/germylated allylic chlorides is reported. The silyl/germyl group governs the regioselectivity, and the transformation affords enantiomerically enriched unsymmetrical 1,3-disubstituted allyl aryl ethers with great regiocontrol in good yields and with excellent enantioselectivities. Notably, no nickel-mediated C-O bond activation is observed at room temperature. The synthetic value of these densely functionalized silicon-containing building blocks is demonstrated in a series of chemoselective transformations, including a [3,3]-sigmatropic rearrangement for the construction of an α-chiral silane.
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  • 文章类型: Journal Article
    Silacycles在药物化学领域表现出巨大的应用潜力,农业化学,和材料科学。因此,合成这些化合物的有效方法的开发引起了越来越多的关注。这里,我们报道了一种有效的Cu催化的芳基亚甲基环丙烷与氢硅烷的对映选择性氢化硅烷化,这允许在温和条件下以良好的产率和优异的对映选择性和非对映选择性快速组装各种富含对映体的碳和硅立体异构硅杂环戊烷。手性硅中心上Si-H键的进一步立体定向转化扩展了这些C-和Si-立体异构硅环戊烷的多样性。
    Silacycles have exhibited significant potential for application in the fields of medicinal chemistry, agrochemistry, and materials science. Accordingly, the development of effective methods for synthesizing these compounds has attracted increasing attention. Here, we report an efficient Cu-catalyzed enantioselective hydrosilylation of arylmethylenecyclopropanes with hydrosilanes, that allows the rapid assembly of various enantioenriched carbon- and silicon-stereogenic silacyclopentanes in good yields with excellent enantioselectivities and diastereoselectivities under mild conditions. Further stereospecific transformation of the Si-H bond on the chiral silicon center expands the diversity of these C- and Si-stereogenic silacyclopentanes.
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  • 文章类型: Journal Article
    由于烯烃的两个邻键交叉π键的同时构建,烯烃的双官能化代表了建立分子复杂性的最直接的方案之一。控制该事件的立体化学结果是非常有吸引力但具有挑战性的。在过去的几年里,可见光和Ni催化的烯烃不对称双官能化为控制区域和对映选择性的饱和碳中心的构建提供了环境良性且有前途的解决方案。在这个概念中,总结了通过可见光和镍催化实现的烯烃的区域和对映选择性双官能化的主动性和进展。此外,已经讨论了发展可见光介导的Ni催化的烯烃不对称双官能化的进一步努力和方向。
    Difunctionalizations of alkenes represent one of the most straightforward protocols to build molecular complexity due to the simultaneous construction of two vicinal bonds cross π-bond of alkenes. It is extremely attractive yet challenging to control the stereochemistry outcome of this event. Over the past years, visible-light and Ni-catalyzed asymmetric difunctionalizations of alkenes provide an environmental benign and promising solution for the construction of saturated carbon centers with the control of regio- and enantioselectivity. In this Concept, the initiative and progress of regio- and enantioselective difunctionalizations of alkenes enabled by visible-light and nickel catalysis has been summarized. Moreover, further efforts and directions for the development of visible-light mediated Ni-catalyzed asymmetric difunctionalizations of alkenes has been discussed.
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  • 文章类型: Journal Article
    杂芳族N-氧化物,以其高度极性的N-O键和坚固的结构而闻名,自发现米诺地尔以来,表现出显著的生物活性,并在各种药物开发项目中发挥了关键作用。此外,杂芳族N-氧化物,具有轴向手性双芳基骨架,是有机合成中不可缺少的路易斯碱催化剂和配体。尽管它们很重要,合成这些手性化合物具有挑战性,需要手性起始材料或拆分过程。催化策略依赖于杂芳族N-氧化物化合物的官能化,导致骨骼多样性相对有限的产品。这项研究介绍了一种通过从头杂芳族N-氧化物环形成来合成联芳基N-氧化物的Cu催化的偏选择性方法。这种温和有效的方法实现了优异的立体选择性(高达99:1er),能够用新型杂芳族支架生产广泛的N-氧化物。轴向手性N-氧化物产物3f表现出作为路易斯碱催化剂的高立体选择性和可循环利用性。此外,产品3e对三阴性乳腺癌具有良好的治疗效果,MDA-MB-231和MDA-MB-468细胞的IC50值为4.8和5.2μm,分别。这项研究不仅推进了具有挑战性的手性杂芳族N-氧化物的合成,而且还鼓励在发现生物活性小分子方面进一步探索N-氧化物实体。
    Heteroaromatic N-oxides, renowned for their highly polar N─O bond and robust structure, exhibit significant bioactivities and have played a pivotal role in various drug development projects since the discovery of Minoxidil. Moreover, heteroaromatic N-oxides, featuring axially chiral biaryl frameworks, are indispensable as Lewis base catalysts and ligands in organic synthesis. Despite their importance, synthesizing these chiral compounds is challenging, necessitating chiral starting materials or resolution processes. Catalytic strategies rely on the functionalization of heteroaromatic N-oxide compounds, leading to products with a relatively limited skeletal diversity. This study introduces a Cu-catalyzed atroposelective method for synthesizing biaryl N-oxides via de novo heteroaromatic N-oxide ring formation. This mild and efficient approach achieves excellent stereoselectivities (up to 99:1 er), enabling the production of a wide array of N-oxides with novel heteroaromatic scaffolds. The axially chiral N-oxide product 3f demonstrates high stereoselectivity and recyclability as a Lewis base catalyst. Additionally, product 3e exhibits promising therapeutic efficacy against triple-negative breast cancer, with IC50 values of 4.8 and 5.2 µm in MDA-MB-231 and MDA-MB-468 cells, respectively. This research not only advances the synthesis of challenging chiral heteroaromatic N-oxides but also encourages further exploration of N-oxide entities in the discovery of bioactive small molecules.
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  • 文章类型: Journal Article
    在碳-碳双键上没有取代基的空间位阻较小的链烯酸底物的对映体选择性卤代内酯化仍然是一个艰巨的挑战。为了解决这个限制,我们在此报道了由BINOL衍生的手性双官能硫化物催化的5-己烯酸衍生物的不对称溴内酯化。
    Enantioselective halolactonizations of sterically less hindered alkenoic acid substrates without substituents on the carbon-carbon double bond have remained a formidable challenge. To address this limitation, we report herein the asymmetric bromolactonization of 5-hexenoic acid derivatives catalyzed by a BINOL-derived chiral bifunctional sulfide.
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  • 文章类型: Journal Article
    天然产物中广泛存在平面手性骨架,生物活性化合物,和其他功能分子。尽管在过去几年中在中心或轴向手性分子的不对称合成领域取得了重大进展,平面手性的对映选择性构建仍然是一个很大的障碍,在这一领域已经做出了许多努力。以前的工作主要集中在平面手性[2,2]-对环烷基和茂金属的组装。这篇小综述描述了平面手性大环的不对称催化合成的最新进展,包括安莎连锁建设,平面编队和非对称转换策略。预计此Minireview将作为开发新的非常规程序以获取平面手性骨架的灵感来源。
    Planar chiral skeletons widely exist in natural products, bioactive compounds, and other functional molecules. Although significant progress has been made in the field of asymmetric synthesis of central or axial chiral molecules over the past years, enantioselective constructing of planar chirality is still a big obstacle and numerous efforts have been made in this field. Previous works have mainly focused on the assembly of planar chiral [2,2]-paracyclophanes and metallocenes. This Minireview describes the recent advancements on asymmetric catalytic synthesis of planar chiral macrocycles, including ansa chain construction, plane formation and asymmetric transformation strategies. It is anticipated that this Minireview will sever as a source of inspiration for developing new unconventional procedures for access to planar chiral skeletons.
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  • 文章类型: Journal Article
    由于该特性在药物发现中提供的独特优势,因此在化学合成中,对慢异构小分子的合理设计变得越来越普遍。不对称催化,和脊骨活动。在这项研究中,我们设计了一个结构稳定的β-咔啉的合成六步。我们的合成利用了创新的格氏加成/消除反应,该反应形成了炔-炔酰胺前体,然后在铑(I)催化的[2222]环三聚反应中与氰基甲酸乙酯反应,以优异的收率得到阻转异构的β-咔啉,良好的对映选择性,和优异的区域选择性。描述了这种转换的广泛优化。还对各个阻转异构体进行了外消旋化动力学实验,并通过圆二色性确定了它们的绝对构型。
    The rational design of atropisomeric small molecules is becoming increasingly common in chemical synthesis as a result of the unique advantages this property provides in drug discovery, asymmetric catalysis, and chiroptical activity. In this study, we designed a synthesis of a configurationally stable β-carboline in six steps. Our synthesis made use of an innovative Grignard addition/elimination reaction that formed an yne-ynamide precursor that then reacted with ethyl cyanoformate in a rhodium(I)-catalyzed [2+2+2] cyclotrimerization reaction to give the atropisomeric β-carboline in excellent yield, good enantioselectivity, and excellent regioselectivity. Extensive optimization of this transformation is described. Racemization kinetics experiments were also conducted on the individual atropisomers and their absolute configurations were determined by circular dichroism.
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  • 文章类型: Journal Article
    (R,R)-Teth-TsDPEN-Ru(II)配合物在温和条件下通过不对称转移氢化/动态动力学拆分(ATH-DKR)促进了α-烷基-β-酮醛的一锅法双C=O还原。在这个过程中,以良好的产率(41-87%)和优异的对映选择性(所有化合物的ee>99%)获得了十种反2-苄基-1-苯基丙烷-1,3-二醇(85:15至92:8dr)。值得注意的是,醛部分的优先还原导致原位形成2-苄基-3-羟基-1-苯基丙-1-酮中间体。这些中间体在通过氢键增强反应性和立体选择性方面起关键作用。
    The (R,R)-Teth-TsDPEN-Ru(II) complex promoted the one-pot double C=O reduction of α-alkyl-β-ketoaldehydes through asymmetric transfer hydrogenation/dynamic kinetic resolution (ATH-DKR) under mild conditions. In this process, ten anti-2-benzyl-1-phenylpropane-1,3-diols (85:15 to 92:8 dr) were obtained in good yields (41-87%) and excellent enantioselectivities (>99% ee for all compounds). Notably, the preferential reduction of the aldehyde moiety led to the in situ formation of 2-benzyl-3-hydroxy-1-phenylpropan-1-one intermediates. These intermediates played a crucial role in enhancing both reactivity and stereoselectivity through hydrogen bonding.
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  • 文章类型: Journal Article
    尽管存在三种对丙炔氧基吲哚的竞争反应,我们报道了对映选择性炔丙基[2,3]-Wittig重排和Conia-ene型反应之间的化学选择性转换,抑制[1,2]-Wittig型重排。以C1对称咪唑烷-吡咯并咪唑酮吡啶为配体,以Ni(acac)2为路易斯酸,通过不对称炔丙基[2,3]-Wittig重排,以高达98%的产率和99%的ee获得了含有丙烯基的多种3-羟基3-取代的羟吲哚。在AgOTf-Duanphos存在的情况下,通过Conia-烯型反应给出的手性螺环二氢呋喃羟吲哚的产率高达98%,ee高达91%。
    Despite the existence of three competing reactions for propargyloxyoxindoles, we report a chemoselectivity switch between enantioselective propargyl [2,3]-Wittig rearrangement and Conia-ene-type reactions, with suppression of the [1,2]-Wittig-type rearrangement. Using C1-symmetric imidazolidine-pyrroloimidazolone pyridine as the ligand and Ni(acac)2 as the Lewis acid, diverse 3-hydroxy 3-substituted oxindoles containing allenyl groups were obtained in up to 98% yield and 99% ee via asymmetric propargyl [2,3]-Wittig rearrangement. In the presence of AgOTf-Duanphos, chiral spiro dihydrofuran oxindoles were given in up to 98% yield and 91% ee through a Conia-ene-type reaction.
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  • 文章类型: Journal Article
    手性农药的不同构型对其生物活性有显著影响。高光学纯度手性农药因其毒性小等优点,已成为新型农药研究领域的突出课题。更高的效率,并降低了残留水平。然而,大多数具有手性元素的市售农药仍以外消旋形式使用。迄今为止,不对称催化已成为各种手性农药和新型手性农药活性分子对映选择性合成的通用工具。这种观点提供了各种不对称催化方法在许多新型农药活性分子的容易制备中的应用的全面概述。最后,我们对这一高度活跃的研究方向的未来发展也提出了自己的展望。
    The different configurations of chiral pesticides generally have significant influence on their biological activities. Chiral agrochemicals with high optical purities have become a prominent topic in the research field of new pesticides due to their advantages including lower toxicity, higher efficiency, and reduced residue levels. However, most commercially available pesticides that possess chiral elements are still used in their racemic forms. To date, asymmetric catalysis has emerged as a versatile tool for the enantioselective synthesis of various chiral agrochemicals and novel chiral pesticide active molecules. This perspective provides a comprehensive overview of the applications of diverse asymmetric catalytic approaches in the facile preparation of numerous novel pesticide active molecules, and our own outlook on the future development of this highly active research direction is also presented at the end of this review.
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