Conjugate addition of silyl groups to β-unsubstituted enones, & Si-to-OH conversion: a synthesis of (±)-lavandulol
作者:Ian Fleming、Duckhee Lee
DOI:10.1016/0040-4039(96)01519-5
日期:1996.9
TMS chloride raises the yield in the conjugate addition of silylcuprates and zincates to β-unsubstituted enones, and Si-to-OH conversion is possible using the 2-methylbut-2-enyl(diphenyl)silyl group in the presence of highly nucleophilic alkenes. Both reactions are used in a synthesis of lavandulol.
[<i>n</i>]Dendralenes as a Platform for Selective Catalysis: Ligand-Controlled Cu-Catalyzed Chemo-, Regio-, and Enantioselective Borylations
作者:Camille Desfeux、Céline Besnard、Clément Mazet
DOI:10.1021/acs.orglett.0c01892
日期:2020.11.6
We report the development of two complementary methods for the Cu-catalyzed anti-Markovnikov borylation of one specific olefin in 2-substituted [n]dendralenes (n = 3–6). The first protocol operates with a bisphosphine ligand and occurs with high regio- and chemoselectivity for the terminal double bond, independently of the number of cross-conjugated alkenes. We show that the use of a chiral phosphanamine
我们报告了在2个取代的[ n ]树枝状烯(n = 3–6)中一种特定烯烃的Cu催化的反Markovnikov硼化的两种互补方法的发展。第一种方案使用双膦配体,并且对末端双键具有高区域选择性和化学选择性,而与交叉共轭烯烃的数量无关。我们表明,使用手性膦胺配体可以使与[ n ]树枝状烯烃中的末端烯烃交叉共轭的烯烃具有高度的化学,区域和对映选择性的硼化作用。
Polycyclic Polyprenylated Acylphloroglucinols: An Emerging Class of Non-Peptide-Based MRSA- and VRE-Active Antibiotics
In the past 20 years, peptide‐based antibiotics, such as vancomycin, teicoplanin, and daptomycin, have often been considered as second‐line antibiotics. However, in recent years, an increasing number of reports on vancomycin resistance in pathogens appeared, which forces researchers to find novel lead structures for potent new antibiotics. Herein, we report the total synthesis of a defined endo‐type B
The total synthesis of hyperpapuanone, hyperibone L, epi-clusianone and oblongifolin A
作者:Nicole Biber、Katrin Möws、Bernd Plietker
DOI:10.1038/nchem.1170
日期:2011.12
Polyprenylated polycyclic acylphloroglucines (PPAPs) are a family of natural products that possess a wide range of different important biological activities because of the relative position and configuration of four substituents that decorate one common central bicyclo[3.3.1]nonane-2,4,9-trione core. The rigid bicyclic framework with its lipophilic side chains and its hydrophilic trione moiety represents a nature-derived lead structure that arranges the substituents (R1 to R4) into a defined topographical orientation. As the substituents are responsible for the biological activities, the seven-step synthetic approach presented here sets the stage for an iterative introduction of R1 to R4 and thus generates structurally diverse trans-type B PPAPs. Four natural and one non-natural trans-type B PPAPs were prepared starting from acetylacetone with overall yields that ranged from 6 to 22%. The concept of separating framework construction from decorating transformations plus the minimization of protecting-group operations are the key issues for the realization of our synthetic approach. The polyprenylated polycyclic acylphloroglucines (PPAPs) are a family of natural products in which a common core is decorated with four different substituents. Here, a synthetic strategy is presented that separates the core building steps from the core decorating steps, offering a general solution to the synthesis of these natural products that will allow investigation of their biological activities.
多烯化多环酰基氯葡萄糖(PPAPs)是一个天然产品家族,由于装饰一个共同的中心双环[3.3.1]壬烷-2,4,9-三酮核心的四个取代基的相对位置和构型不同,因此具有多种不同的重要生物活性。具有亲油性侧链和亲水性三酮分子的刚性双环框架代表了一种源自自然的先导结构,它将取代基(R1 至 R4)排列成确定的地形方向。由于取代基具有生物活性,本文介绍的七步合成方法为 R1 至 R4 的迭代引入创造了条件,从而产生了结构多样的反式 B 型 PPAP。从乙酰丙酮开始,制备了四种天然和一种非天然反式 B 型 PPAP,总产率在 6% 到 22% 之间。框架构建与装饰转化分离的概念以及保护基操作的最小化是实现我们合成方法的关键问题。多烯化多环酰基氯吡啶(PPAPs)是一个天然产品家族,其中一个共同的核心被四个不同的取代基所装饰。这里介绍的合成策略将核心构建步骤与核心装饰步骤分开,为这些天然产物的合成提供了一个通用解决方案,从而可以研究它们的生物活性。
The enantioselective total synthesis of (+)-clusianone
(+)-Clusianone, an exo-type B PPAP with reported anti-HIV and chemoprotective activities, was synthesized in eleven steps with 97% ee starting from acetylacetone.