222640-88-2Relevant articles and documents
Selecting double bond positions with a single cation-responsive iridium olefin isomerization catalyst
Camp, Andrew M.,Kita, Matthew R.,Blackburn, P. Thomas,Dodge, Henry M.,Chen, Chun-Hsing,Miller, Alexander J.M.
supporting information, p. 2792 - 2800 (2021/03/01)
The catalytic transposition of double bonds holds promise as an ideal route to alkenes of value as fragrances, commodity chemicals, and pharmaceuticals; yet, selective access to specific isomers is a challenge, normally requiring independent development of different catalysts for different products. In this work, a single cation-responsive iridium catalyst selectively produces either of two different internal alkene isomers. In the absence of salts, a single positional isomerization of 1-butene derivatives furnishes 2-alkenes with exceptional regioselectivity and 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 1-butenes, providing insight into strategies for catalyst development based on noncovalent modifications.
Controllable Isomerization of Alkenes by Dual Visible-Light-Cobalt Catalysis
Meng, Qing-Yuan,Schirmer, Tobias E.,Katou, Kousuke,K?nig, Burkhard
, p. 5723 - 5728 (2019/04/03)
We report herein that thermodynamic and kinetic isomerization 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 further. Transformation of exocyclic alkenes into the corresponding endocyclic products could be efficiently realized by using 4CzIPN and Co(acac)2 in the absence of any additional ligands. Spectroscopic and spectroelectrochemical investigations indicate CoI being involved in the generation of a Co hydride, which subsequently adds to alkenes initiating the isomerization.
A new direct allylation of the aromatic compounds with allylic chlorides catalyzed by indium metal
Lim, Hwan Jung,Keum, Gyochang,Kang, Soon Bang,Kim, Youseung,Chung, Bong Young
, p. 1547 - 1550 (2007/10/03)
A new method of the direct allylation reaction for the aromatic compounds with allylic chlorides using a catalytic mount of indium in the presence of CaCO3/4A molecular sieves was developed.
COMPLEXES OF TRANSITION METALS IN THE CHEMISTRY OF CONJUGATED SYSTEMS. III. REACTION OF DIENE HYDROCARBONS WITH ORGANOMAGNESIUM COMPOUNDS IN THE PRESENCE OF SALTS AND COMPLEXES OF TRANSITION METALS
Zubritskii, L. M.,Romashchenkova, N. D.,Petrov, A. A.
, p. 2157 - 2167 (2007/10/02)
The effect of the structure of the reagents and the nature of the catalyst on the direction and selectivity in the reaction of 1,3-dienes and their derivatives with aromatic Grignard reagents was investigated.It was shown that in the presence of salts and complexes of iron(III) 1,3-alkadienes R1CH=C(R2)C(R3)=CH2 react with arylmagnesium halides to form trans-(E)-1-aryl-1,3-alkadienes, whereas the sterically hindered (R2, R3=CH3) cyclic 1,3-alkadienes and also 1,2-alkadienes give mainly adducts (1:1).Catalysis by the phosphine complexes of nickel(II) leads to the formation of telomeric (2:1) (E)-1-aryl-2,7- and (E,E)-1-aryl-2,6-alkadienes.The results demonstrate the determining role of the stereochemical conditions for the coordination of the diene in the course of the reaction and also the significant contribution from the processes of one-electron reduction of the catalyst.
