Palladium-Catalyzed Arylation of Trimethylsilyl Enolates of Esters and Imides. High Functional Group Tolerance and Stereoselective Synthesis of α-Aryl Carboxylic Acid Derivatives
作者:Xiaoxiang Liu、John F. Hartwig
DOI:10.1021/ja031544e
日期:2004.4.28
palladium-catalyzed arylation of trimethylsilyl enolates of esters and imides is reported. In the presence of ZnF2 or Zn(O-t-Bu)2 as an additive, the trimethylsilyl enolates of esters, including those bearing α-alkoxy derivatives, underwent arylation in high yield with high functional group tolerance. This arylation chemistry was extended to ester derivatives bearing chiral auxiliaries to form new tertiary stereocenters
Scalable Total Synthesis, IP3R Inhibitory Activity of Desmethylxestospongin B, and Effect on Mitochondrial Function and Cancer Cell Survival
作者:Maša Podunavac、Artur K. Mailyan、Jeffrey J. Jackson、Alenka Lovy、Paula Farias、Hernan Huerta、Jordi Molgó、Cesar Cardenas、Armen Zakarian
DOI:10.1002/anie.202102259
日期:2021.5.10
The scalablesynthesis of the oxaquinolizidine marine natural product desmethylxestosponginB is based on the early application of Ireland–Claisen rearrangement, macrolactamization, and a late‐stage installation of the oxaquinolizidine units by lactam reduction. The synthesis serves as the source of material to investigate calcium signaling and its effect on mitochondrial metabolism in various cell
oxaquinolizidine 海洋天然产物 desmethylxestospongin B 的可扩展合成是基于 Ireland-Claisen 重排、大环内酰胺化和通过内酰胺还原后期安装 oxaquinolizidine 单元的早期应用。该合成可作为研究钙信号传导及其对包括癌细胞在内的各种细胞类型中线粒体代谢的影响的材料来源。
Palladium-Catalyzed Enantioselective Cycloaddition of Carbonylogous 1,4-Dipoles: Efficient Access to Chiral Cyclohexanones
作者:Barry M. Trost、Zhiwei Jiao
DOI:10.1021/jacs.0c11535
日期:2020.12.30
A novel palladium-mediated carbonylogous 1,4-dipole was developed by in situ deprotonation. By using our own-developed C2-unsymmetric phosphoramidite as supporting ligand, this dipole was applied to the asymmetric synthesis of chiral cyclohexanones via a catalytic [4+2] cycloaddition. Electron-deficient allyliccarbonate was used to generate the highly reactive palladium-mediated dipoles for the first
Practical and Robust Method for Regio- and Stereoselective Preparation of (<i>E</i>)-Ketene <i>tert</i>-Butyl TMS Acetals and β-Ketoester-derived <i>tert</i>-Butyl (1<i>Z</i>,3<i>E</i>)-1,3-Bis(TMS)dienol Ethers
We developed an efficient, practical, robust method for the regio- and stereoselective preparation of (E)-ketene trimethylsilyl acetals (KSAs) derived from tert-butyl esters 1. The reaction was performed under convenient reaction conditions; LDA−TMSCl, 0−5 °C, and cyclopentyl methyl ether (CPME) solvent. Two kinds of (Z)- and (E)-KSAs derived from α-oxygen and α-nitrogen-substituted tert-butyl esters
Efficient Synthesis of Cyclopropanecarboxylic Acid Esters Starting from the Conjugate Addition of Lithium Ester Enolates to 1-Chlorovinyl p-Tolyl Sulfoxides
cyclopropanecarboxylates was achieved in three steps using 1-chlorovinyl p -tolyl sulfoxides as key materials. The conjugate addition of lithium ester enolates to the sulfoxides gave tert -butyl 4-chloro-4-( p -tolylsulfinyl)butanoates in high yield. The p -tolylsulfinyl group in the resultant adducts was then removed by the sulfoxide–magnesiumexchange reaction with i -PrMgCl at –60 °C. Cyclization of the desulfinylated