(1<i>R</i>)-(+)-Camphor and Acetone Derived α′-Hydroxy Enones in Asymmetric Diels−Alder Reaction: Catalytic Activation by Lewis and Brønsted Acids, Substrate Scope, Applications in Syntheses, and Mechanistic Studies
作者:Patricia Bañuelos、Jesús M. García、Enrique Gómez-Bengoa、Ada Herrero、José M. Odriozola、Mikel Oiarbide、Claudio Palomo、Jesús Razkin
DOI:10.1021/jo9023039
日期:2010.3.5
enones as reaction partners of the Diels−Alder reaction are shown, with especial focus on their potentials and limitations in solving the above difficult cases. α′-Hydroxy enones are able to bind reversibly to bothLewisacids and Brønsted acids, forming 1,4-coordinated species that are shown to efficiently engage in these inherently difficult Diels−Alder reactions. On these bases, a convenient control
nutrient-deprived pancreaticcancer cells. In order to overcome this limitation, the search for novel agents that can eliminate cancer cells’ adaptations to nutrition starvation, also known as “antiausterity” agents, represents a promising strategy to make the cancer cells susceptible to treatment. The natural product (+)-nicolaioidesin C (Nic-C) was found to have potent antiausterityactivity against the
人类胰腺肿瘤本质上是缺乏血管的,其肿瘤微环境往往因不受控制的异质生长而导致缺氧和严重营养缺乏,这种现象被称为“紧缩”。然而,即使在如此低营养和缺氧的微环境中,胰腺肿瘤细胞也具有适应和繁荣的固有能力。吉西他滨和紫杉醇等抗癌药物针对快速增殖的细胞,通常对营养缺乏的胰腺癌细胞无效。为了克服这一限制,寻找能够消除癌细胞对营养饥饿的适应的新药物(也称为“抗紧缩”药物)代表了一种使癌细胞对治疗敏感的有前途的策略。天然产物 (+)-nicolaioidesin C (Nic-C) 被发现对营养缺乏条件下的 PANC-1 人胰腺癌细胞系具有有效的抗紧缩活性。然而,其体内功效尚未经过测试。为了解决这个问题,我们合成了外消旋形式的 Nic-C,并评估了其在人类胰腺癌异种移植模型中的抗肿瘤潜力。 Nic-C 抑制胰腺癌细胞迁移和集落形成,并以剂量依赖性方式显着抑制 MIA PaCa-2 异种移植物中的肿瘤生
Electron Transfer-Initiated Diels−Alder Cycloadditions of 2′-Hydroxychalcones
作者:Huan Cong、Dustin Ledbetter、Gerard T. Rowe、John P. Caradonna、John A. Porco
DOI:10.1021/ja803094u
日期:2008.7.1
An efficient approach to cyclohexenyl chalcones employing highly electron rich 2'-hydroxychalcone dienophiles via electron transfer-initiated Diels-Alder cycloaddition is described. Using the methodology, the total synthesis of nicolaiodesin C has been accomplished.
Asymmetric Total Synthesis and Biological Evaluation of Proapoptotic Natural Myrcene-Derived Cyclohexenyl Chalcones
Based on a bioinspired asymmetricDiels–Alder cycloaddition using a chiral Evans oxazolidinone, the first total synthesis of both enantiomers of two myrcene-derived cyclohexenyl chalcones, fislatifolione and fislatifolic acid, has been carried out. This strategy was also applied to the total synthesis of nicolaiodesin C. These naturalproducts, as well as their synthetic intermediates, were evaluated