Regio‐ and Stereoselective Thianthrenation of Olefins To Access Versatile Alkenyl Electrophiles
作者:Junting Chen、Jiakun Li、Matthew B. Plutschack、Florian Berger、Tobias Ritter
DOI:10.1002/anie.201914215
日期:2020.3.27
we report a regioselective alkenyl electrophile synthesis from unactivated olefins that is based on a direct and regioselective C-H thianthrenation reaction. The selectivity is proposed to arise from an unusual inverse-electron-demand hetero-Diels-Alder reaction. The alkenyl sulfonium salts can serve as electrophiles in palladium- and ruthenium-catalyzed cross-coupling reactions to make alkenyl C-C,
Allylic C–H amination is currently accomplished with (sulfon)amides or carbamates. Here we show the first allylicamination that can directly afford alkyl allylamines, enabled by the reactivity of thianthrene-based nitrogen sources that can be prepared from primary amines in a single step.
[EN] CYCLOALKYLNORBORNENE MONOMERS, POLYMERS DERIVED THEREFROM AND THEIR USE IN PERVAPORATION<br/>[FR] MONOMÈRES DE CYCLOALKYLNORBORNÈNE, POLYMÈRES ISSUS DE CEUX-CI ET LEUR UTILISATION EN PERVAPORATION
申请人:PROMERUS LLC
公开号:WO2014025735A1
公开(公告)日:2014-02-13
Embodiments in accordance with the present invention provide forming various polycycloalkyl polynorbornene polymers and copolymers which are useful for forming pervaporation membranes, the membranes themselves and methods of making such membranes.
Pd-Catalyzed Decarbonylative Heck Olefination of Aromatic Carboxylic Acids Activated in situ with Di-<i>tert</i>-butyl Dicarbonate
作者:Lukas J. Gooßen、Jens Paetzold、Lars Winkel
DOI:10.1055/s-2002-34227
日期:——
The first protocol for a direct Heck olefination of aromatic carboxylic acids has been developed. By treatment with commercially available di-tert-butyl dicarbonate, the carboxylic acids are converted in situ into the mixed anhydrides, which in the presence of a palladium catalyst react with olefins to give styrene derivatives. As by-products, only volatile CO and CO2 along with tert-butanol are formed, making the work-up of the reaction products particuarly easy. A mixture of PdCl2, LiCl and γ-picoline was identified to be the most effective catalyst system.
Mechanism of catalytic migration of the double bond in 2-vinylnorbornanes
作者:V. V. Zamalyutin、R. S. Shamsiev、V. R. Flid
DOI:10.1007/s11172-022-3639-3
日期:2022.10
Liquid-phase hydrogenation of 5-vinylbicyclo[2.2.1]hept-2-ene (5-vinyl-2-norbornene, VNE) existing as a mixture of endo- and exo-isomers in the presence of a palladium catalyst (0.25% Pd/γ-Al2O3, or PC-25) is a complex consecutive-parallel process proceeding via the formation of (endo/exo)-2-vinylnorbornanes. Subsequent hydrogenation of the latter is preceded by quantitative isomerization of the vinyl group to the ethylidene one. The mechanism of the phenomenon was studied experimentally and theoretically. It was established that isomerization of 2-vinylnorbornanes to 2-ethylidenenorbornanes requires the presence of palladium (as the active component of the catalyst) and hydrogen in the reaction system. All reaction products were identified and the material balance of the process was studied. According to DFT PBE/SBK quantum chemical calculations, migration of the multiple bond in 2-vinylnorbornanes on the Pd(111) face of the model cluster Pd21(H)2 is of allylic character.