Dual Activation of Unsaturated Amides with Schwartz's Reagent: A Diastereoselective Access to Cyclopentanols and N,O‐Dimethylcyclopentylhydroxylamines.
The concomitant generation of a nucleophilic and an electrophilic site from unsaturated Weinreb amide by using Cp2Zr(H)Cl) as the unique reagent was developed to promote a cyclisation reaction. The access to trans-2-substituted cyclopentanols or cyclopentylhydroxylamines can be selectively driven by a judicious choice of the cyclisationpromotor. An access to cis-3-substituted is also described.
Formal Aza‐Wacker Cyclization by Tandem Electrochemical Oxidation and Copper Catalysis
作者:Xiangli Yi、Xile Hu
DOI:10.1002/anie.201814509
日期:2019.3.26
In oxidative electrochemical organic synthesis, radical intermediates are often oxidized to cations on the way to final product formation. Herein, we describe an approach to transform electrochemically generated organic radical intermediates into neutral products by reaction with a metalcatalyst. This approach combines electrochemical oxidation with Cu catalysis to effect formal aza‐Wacker cyclization
Linear Selective Isomerization/Hydroformylation of Unsaturated Fatty Acid Methyl Esters: A Bimetallic Approach
作者:Tom Gaide、Jonas Bianga、Kim Schlipköter、Arno Behr、Andreas J. Vorholt
DOI:10.1021/acscatal.7b00249
日期:2017.6.2
under mild conditions. Ethyl 4-decenoate was subsequently applied as a second model substrate to identify challenges associated with the longerchain length of the unsaturated ester. Finally, methyl oleate was converted using the developed catalyst system. High aldehyde yields of 74% (at 99% conversion) with an l/b-ratio of 91/9 are obtained.
Dienyne Ring-Closing Metathesis Approach for the Construction of Taxosteroids
作者:María J. Aldegunde、Rebeca García-Fandiño、Luis Castedo、Juan R. Granja
DOI:10.1002/chem.200601685
日期:2007.6.15
hybrid compounds-the taxosteroids-possessing carbon frameworks incorporating moieties characteristic of both taxanes (such as ABrings) and steroids (i.e., CD system and side chain). This tandem cyclization is highly stereoselective, allowing the one-step formation of the bicyclo[5.3.1]undecene system characteristic of taxol. In this work we describe the scope and limitations of such cyclizations.
Selective Production of Terminally Unsaturated Methyl Esters from Lactones Over Metal Oxide Catalysts
作者:Zachary J. Brentzel、Madelyn R. Ball、James A. Dumesic
DOI:10.1007/s10562-018-2507-0
日期:2018.10
Metal oxidecatalysts were studied for their selectivity for the production of a terminally unsaturated methyl ester, methyl 5-hexenoate (M5H), from a 6 carbon, 6-membered ring lactone, δ-hexalactone (DHL). A 15 wt% Cs/SiO2 catalyst had a selectivity of 55% to M5H. This selectivity was the highest of the metal oxidecatalysts studied, which were Cs/SiO2, MgO, SrO, CeO2, ZrO2, Ta2O5, MgAl2O4, and a