Dynamic Kinetic Resolution of Biaryl Atropisomers via Peptide-Catalyzed Asymmetric Bromination
作者:Jeffrey L. Gustafson、Daniel Lim、Scott J. Miller
DOI:10.1126/science.1188403
日期:2010.6.4
widespread use of axially chiral, or atropisomeric, biarylligands in modern synthesis and the occurrence of numerous natural products exhibiting axial chirality, few catalytic methods have emerged for the direct asymmetric preparation of this compound class. Here, we present a tripeptide-derived small-molecule catalyst for the dynamic kinetic resolution of racemic biaryl substrates. The reaction proceeds
conditions to synthesize dehydroaltenusin analogs bearing both polycyclic cyclohexadienone and benzopyrolactone moieties. This methodology achieves phenolic radical-mediated self-dearomatization promoted by electricity at anode in an undivided cell, having good functional group tolerance, and more eco-friendliness. The obtained products are dehydroaltenusin analogs which possess potentially pharmacological
chloroperoxidase (CiVCPO)-catalyzed tribromination of biaryls to transform freely rotating biaryl bonds to a sterically hindered axis is described. The strategy was used to produce 14 examples in analytical and preparative scales. The combination of Suzukicoupling and chemoenzymatic halogenations has enabled the chemoenzymatic one-pot synthesis of the tribrominated products in aqueous phase.
描述了钒依赖性氯过氧化物酶( Ci VCPO) 催化的联芳基三溴化反应,将自由旋转的联芳基键转变为空间位阻轴。该策略用于生成 14 个分析和制备规模的示例。Suzuki 偶联和化学酶促卤化的结合使得能够在水相中化学酶促一锅法合成三溴化产物。
The conformationally restricted, spatially defined macrocyclic ring system of formula (I) is constituted by three distinct molecular parts: Template A, conformation Modulator B and Bridge C. Macrocycles described by this ring system I are readily manufactured by parallel synthesis or combinatorial chemistry in solution or on solid phase. They are designed to interact with a variety of specific biological target classes, examples being agonistic or antagonistic activity on G-protein coupled receptors (GPCRs), inhibitory activity on enzymes or antimicrobial activity. In particular, these macrocycles show inhibitory activity on endothelin converting enzyme of subtype 1 (ECE-1) and/or the cysteine protease cathepsin S (CatS), and/or act as antagonists of the oxytocin (OT) receptor, thyrotropin-releasing hormone (TRH) receptor and/or leukotriene B4 (LTB4) receptor, and/or as agonists of the bombesin 3 (BB3) receptor, and/or show antimicrobial activity against at least one bacterial strain. Thus they are showing great potential as medicaments for a variety of diseases.
式(I)的构象受限、空间限定的大环环系统由三个不同的分子部分构成,分别是模板 A、构象调节剂 B 和桥 C:这种环系统 I 所描述的大环很容易通过平行合成或组合化学在溶液或固相中制造出来。它们可与各种特定的生物靶标相互作用,例如对 G 蛋白偶联受体(GPCR)的激动或拮抗活性、对酶的抑制活性或抗菌活性。特别是,这些大环化合物对亚型 1 内皮素转换酶(ECE-1)和/或半胱氨酸蛋白酶 cathepsin S(CatS)具有抑制活性,和/或可作为催产素(OT)受体的拮抗剂、或白三烯 B4(LTB4)受体的拮抗剂,和/或作为弹力素 3(BB3)受体的激动剂,和/或对至少一种细菌菌株具有抗菌活性。因此,它们作为治疗各种疾病的药物显示出巨大的潜力。
Synthesis of Fluorenone and Anthraquinone Derivatives from Aryl- and Aroyl-Substituted Propiolates
作者:Florian Pünner、Justin Schieven、Gerhard Hilt
DOI:10.1021/ol4023276
日期:2013.9.20
Fluorenone derivatives were generated from aryl-substituted propiolates via a cobalt-catalyzed Diels-Alder reaction/DDQ-oxidation and Friedel-Crafts-type cyclization. Several functional groups are tolerated, and good to excellent overall yields (up to 89%) could be achieved. For the synthesis of anthraquinone derivatives, aroyl-substituted propiolates were applied in a zinc iodide catalyzed Die Is Alder reaction with 1,3-dienes. The subsequent DDQ oxidation and Friedel-Crafts-type cyclization led to symmetrical as well as some unsymmetrical anthraquinones in good to excellent yields of up to 87% over the three-step reaction sequence.