27319-06-8Relevant academic research and scientific papers
Superelectrophilic Fe(III)-Ion Pairs as Stronger Lewis Acid Catalysts for (E)-Selective Intermolecular Carbonyl-Olefin Metathesis
Albright, Haley,Schindler, Corinna S.,Vonesh, Hannah L.
supporting information, p. 3155 - 3160 (2020/04/21)
An intermolecular carbonyl-olefin metathesis reaction is described that relies on superelectrophilic Fe(III)-based ion pairs as stronger Lewis acid catalysts. This new catalytic system enables selective access to (E)-olefins as carbonyl-olefin metathesis products. Mechanistic investigations suggest the regioselective formation and stereospecific fragmentation of intermediate oxetanes to be the origin of this selectivity. The optimized conditions are general for a variety of aryl aldehydes and trisubstituted olefins and are demonstrated for 28 examples in up to 64% overall yield.
Cobalt-Catalyzed Z to e Isomerization of Alkenes: An Approach to (E)-β-Substituted Styrenes
Liu, Hongmei,Xu, Man,Cai, Cheng,Chen, Jianhui,Gu, Yugui,Xia, Yuanzhi
supporting information, p. 1193 - 1198 (2020/02/04)
An efficient cobalt-catalyzed Z to E isomerization of β-substituted styrenes using the amido-diphosphine ligand was developed, delivering the (E)-isomers with good functional tolerance and high stereoselectivity. The reaction could be scaled up to gram-scale with a catalyst loading of 0.1 mol %, using a mixture of (Z)- and (E)-alkene as the starting material. Preliminary mechanistic studies indicated that cobalt(I)-hydride and a benzylic-cobalt species were probably involved in the reaction, as supported by experiments and DFT calculations.
A Stereoconvergent Cyclopropanation Reaction of Styrenes
del Hoyo, Ana M.,Herraiz, Ana G.,Suero, Marcos G.
supporting information, p. 1610 - 1613 (2017/02/05)
The first stereoconvergent cyclopropanation reaction by means of photoredox catalysis using diiodomethane as the methylene source is described. This transformation exhibits broad functional group tolerance and it is characterized by an excellent stereocontrol en route to trans-cyclopropanes regardless of whether E- or Z-styrene substrates were utilized.
KINETICS OF ISOMERIZATION OF ALLYLBENZENE AND ITS DERIVATIVES
Polkanov, M. A.,Shapiro, I. O.,Chernoplekova, V. A.,Shatenshtein, A. I.
, p. 1123 - 1127 (2007/10/02)
The kinetics of isomerization with migration of the double bond in allylbenzene and its derivatives were measured in the lithium tert-butoxide-N,N-dimethylacetamide and potassium tert-butoxide-tert-butyl alcohol catalytic systems.The composition of the catalytically active particles in these solvents was established.The dependence of the isomerization rate of substitued allylbenzenes on the position and electronic chracteristics of the substituents is described by the Hammett equation.The effects of substituents and the characteristics of the catalytic systems on thekinetics of the ionization of substituted toluenes and the isomerization of substituted allylbenzenes are similar.It is concluded that these reactions have a common mechanism.
