Long-acting contraceptive agents: Levonorgestrel esters of unsaturated acids
摘要:
Esters of levonorgestrel (13 beta-ethyl-17 beta-ethynyl-17 beta-hydroxygon-4-en-3-one) with a variety of unsaturated carboxylic acids have been synthesized for evaluation as potential long-acting, injectable contraceptive agents.
Palladium-catalyzed carbonylation of 2,4-enyne carbonates in an alcohol and under balloon pressure of CO proceeds through 1,5-substitution to yield (E)-2,3,5-trienoates. The olefin geometry of the substrate is important to control the overall stereochemistry of this alkoxycarbonylation method. The reaction proceeds through successive formation of π-allylpalladium with an R3 group oriented syn and σ-allenyl
β—Mono- and β,β—disubstituted α,β-unsaturatedesters can be prepared in good yields stereoselectively by the stepwise alkylation and alkoxycarbonylation of 2-bromo-1-alkenylboronates.
Palladium-Catalyzed Vinylation of Acetylenic Iodides under Solid-Liquid Please-Transfer Conditions
作者:Tuyet Jeffery
DOI:10.1055/s-1987-27851
日期:——
Methyl (E)-enynoates and (E)-enyones can be obtained in fair yields by Pd-catalyzed vinylation of 1-iodo-1-alkynes under solid-liquid phase-transfer conditions (potassium carbonate or sodium carbonate/ tetrabutylammonium chloride).
Enantioselective Synthesis of α-Chiral Propargylic Silanes by Copper-Catalyzed 1,4-Selective Addition of Silicon Nucleophiles to Enyne-Type α,β,γ,δ-Unsaturated Acceptors
作者:Wenbin Mao、Martin Oestreich
DOI:10.1021/acs.orglett.0c03046
日期:2020.10.16
A copper-catalyzed deconjugative addition of silicon nucleophiles to a broad range of enyne-type α,β,γ,δ-unsaturated acceptors with high enantiocontrol is reported. The method is 1,4-selective with hardly any formation of the 1,6-adduct. The double-bond geometry is shown to be critical for achieving this chemoselectivity: exclusive 1,4-addition for E and predominant 1,6-addition for Z. By this, E-configured
A New Route to the Synthesis of (<i>E</i>)- and (<i>Z</i>)-2-Alkene-4-ynoates and Nitriles from <i>vic</i>-Diiodo-(<i>E</i>)-alkenes Catalyzed by Pd(0) Nanoparticles in Water
作者:Brindaban C. Ranu、Kalicharan Chattopadhyay
DOI:10.1021/ol0708121
日期:2007.6.1
and (Z)-2-alkene-4-ynoates and -nitriles by a simple reaction of vic-diiodo-(E)-alkenes with acrylicesters and nitriles catalyzed by in situ prepared Pd(0) nanoparticles in water has been developed. Addition of acrylicesters leads to (E)-isomers exclusively, whereas (Z)-isomers are obtained in high stereoselectivity from reactions of acrylonitrile. The aqueous slurry of Pd nanoparticles is recycled