2,3-Dihalo-1-propenes as Building Blocks in Cu(I)-Catalyzed Domino Reactions: Efficient and Selective Synthesis of Furans
摘要:
The Cu(I)-catalyzed reaction of 2,3-dibromo-1-propenes with beta-ketoesters and 1,3-diketones, respectively, in DMF at 120 degrees C using Cs2CO3 as a base and hydroquinone as an additive exclusively delivers 2,3,5-trisubstituted furans and related compounds with yields up to 96%. The highly regioselective domino process is based on an intermolecular C-allylation followed by an intramolecular Ullmann type O-vinylation and a double bond isomerization.
Versatile synthesis of bicyclo[4.3.0]nonenes and bicyclo[4.4.0]decenes by a domino Heck-Diels-Alder reaction
作者:Kiah How Ang、Stefan Bräse、Arno G. Steinig、Frank E. Meyer、Amadeu Llebaria、Katharina Voigt、Armin de Meijere
DOI:10.1016/0040-4020(96)00639-4
日期:1996.8
afterwards in a one-pot process) to give bicyclo[4.3.0]nonene and bicyclo[4.4.0]-decene derivatives in good to excellent yields. Among the examples reported are the first cases of intramolecular Heck reactions with a (bromomethylene)cyclopropane starter or/and a methylenecyclopropane terminator which occur without ring opening of the cyclopropyl group.
Enantioselective Total Synthesis of Avrainvillamide and the Stephacidins
作者:Phil S. Baran、Benjamin D. Hafensteiner、Narendra B. Ambhaikar、Carlos A. Guerrero、John D. Gallagher
DOI:10.1021/ja061660s
日期:2006.7.1
complete stereocontrol. The information gained in these model studies enabled an enantioselectivetotalsynthesis of stephacidin A. The absolute configuration of these alkaloids was firmly established in collaboration with Professor William Fenical. A full account of our successful efforts to convert stephacidin A into stephacidin B via avrainvillamide is presented. Finally, the first analogues of these natural
在本文中,提供了有关我们全合成 avrainvillamide 和 stepphacidins 的完整详细信息。在介绍和总结这一结构复杂的抗癌天然产物家族的先前合成研究之后,描述了最终合成方法的演变。因此,为构建这些生物碱共有的特征双环[2.2.2]二氮杂辛烷环系统,提供了三个独立模型研究的详尽描述。第一种和第二种方法试图分别使用正式的 Diels-Alder 和乙烯基自由基途径来构建核心。尽管这些策略未能实现其主要目标,但它们促进了一种新的、机械上有趣的方法的开发,用于合成吲哚烯酰胺,例如在许多生物活性天然产物中发现的那些。描述了这种用于色氨酸衍生物直接脱氢的简单方法的范围和通用性。最后,描述了通往这些生物碱核心的第三条成功途径的细节,其特征是氧化 CC 键的形成。具体而言,两种不同类型的羰基物质(酯和酰胺)的第一次杂偶联以良好的收率、制备规模和完全立体控制完成。在这些模型研究中获得的信息使
An exceptional palladium-catalyzed alkenylation of silyl enol ether in the absence of a fluoride additive
An exceptional intramolecular palladium-catalyzed alkenylation of silyl enolether in the absence of a fluoride additive was developed, and this reaction led to the construction of bicyclo[3.3.1]nonane ring system in reasonable yield. In this type of reactions, trialkylamines were employed as additives instead of previously indispensable fluoride additives.
Brook Rearrangement as Trigger for Carbene Generation: Synthesis of Stereodefined and Fully Substituted Cyclobutenes
作者:Fa-Guang Zhang、Ilan Marek
DOI:10.1021/jacs.7b04255
日期:2017.6.21
Through a sequence that can be performed in a single vessel, involving regio- and diastereoselective copper-catalyzedcarbomagnesiation of cyclopropenes, reaction with acylsilanes, and addition of THF as cosolvent, Brook rearrangement can be triggered to furnish a wide range of cyclobutenes with exceptional diastereoselectivity. Accordingly, stereodefined and highly substituted cyclobutenes with contiguous
Nickel-Catalyzed Intramolecular C−O Bond Formation: Synthesis of Cyclic Enol Ethers
作者:Seo-Jung Han、Ryohei Doi、Brian M. Stoltz
DOI:10.1002/anie.201601991
日期:2016.6.20
efficient and exceptionally mild intramolecular nickel‐catalyzed carbon–oxygen bond‐forming reaction between vinyl halides and primary, secondary, and tertiary alcohols has been achieved. Zinc powder was found to be an essential additive for obtaining high catalyst turnover and yields. This operationally simple method allows direct access to cyclic vinyl ethers in high yields in a single step.