Controllable Isomerization of Alkenes by Dual Visible‐Light‐Cobalt Catalysis
作者:Qing‐Yuan Meng、Tobias E. Schirmer、Kousuke Katou、Burkhard König
DOI:10.1002/anie.201900849
日期:2019.4.16
We report herein that thermodynamic and kineticisomerization of alkenes can be accomplished by the combination of visible light with Co catalysis. Utilizing Xantphos as the ligand, the most stable isomers are obtained, while isomerizing terminal alkenes over one position can be selectively controlled by using DPEphos as the ligand. The presence of the donor–acceptor dye 4CzIPN accelerates the reaction
Tertiary Amines Acting as Alkyl Radical Equivalents Enabled by a P/N Heteroleptic Cu(I) Photosensitizer
作者:Limeng Zheng、Qinfang Jiang、Hanyang Bao、Bingwei Zhou、Shu-Ping Luo、Hongwei Jin、Huayue Wu、Yunkui Liu
DOI:10.1021/acs.orglett.0c03236
日期:2020.11.20
An unprecedented exploration of tertiary amines as alkyl radical equivalents for cross-coupling with aromatic alkynes to access allylarenes has been achieved by a P/N heteroleptic Cu(I)-based photosensitizer under photoredox catalysis conditions. Mechanistic studies reveal that the reaction might undergo radical addition of in situ-generated α-amino radical intermediates to alkynes followed by 1,5-hydrogen
The novel unsaturated arylalkyl ammonium salts described herein are useful as antiarrhythmic agents. A method of treating arrhythmia by increasing the refractoriness of cardiac tissue is provided, as well as pharmaceutical formulations containing such ammonium salts.
Selecting Double Bond Positions with a Single Cation-Responsive Iridium Olefin Isomerization Catalyst
作者:Andrew M. Camp、Matthew R. Kita、P. Thomas Blackburn、Henry M. Dodge、Chun-Hsing Chen、Alexander J. M. Miller
DOI:10.1021/jacs.0c11601
日期:2021.2.24
stereoselectivity. The same catalyst, in the presence of Na+, mediates two positional isomerizations to produce 3-alkenes. The synthesis of new iridium pincer-crown ether catalysts based on an aza-18-crown-6 ether proved instrumental in achieving cation-controlled selectivity. Experimental and computational studies guided the development of a mechanistic model that explains the observed selectivity for various functionalized