54354-35-7Relevant academic research and scientific papers
Photosensitized Cis/Trans Izomerization of 1-(1-Propenyl)cycloalkenes
Inman, Wayne D.,Sanchez, Kenneth A. J.,Chaidez, Manuel A.,Paulson, Donald R.
, p. 4872 - 4881 (2007/10/02)
The photosensitized cis/trans isomerization of a series of 1-(1-propenyl)cycloalkenes is reported.A plot of the photostationary state trans/cis ratio vs the sensitizer triplet energy for 1-(1-propenyl)cyclopentene shows a constant trans/cis ratio of ca. 1.0 with high-energy sensitizers (ET>61 kcal/mol).The plot shows one maxima at ET ca. 55 kcal/mol with low-energy sensitizers (ET61 kcal/mol).This type of plot is very similar to those obtained with acyclic dienes such as piperylene.The 1-(1-propenyl)cyclohexene system shows a similar plot with high-energy sensit izers, but with low-energy sensitizers this system shows two maxima occurring at 56 and 47 kcal/mol, respectively.This double-maxima plot is rationalized by an unsually low trans/cis decay ratio for the s-cis relaxed triplet state of the 1-(1-propenyl)cyclohexene system.This double maxima is not observed in other diene systems due to a high trans/cis decay ratio for their s-cis relaxed triplet states.The photosensitized cis/trans isomerization of 2-ethylidene-10-methyl-1(9)-octalin was also studied as a model for a conformationally locked s-trans system.The 1-(1-propenyl)cycloheptene system undergoes photosensitized cis/trans isomerization, but photostationary cis/trans isomerization data could not be obtained due to a very efficient photosensitized dimerization of this diene system.
Isomerisation de dienes-1,5 fonctionnalises par le fer pentacarbonyle
Rodriguez, J.,Brun, P.,Waegell, B.
, p. 343 - 370 (2007/10/02)
A series of various, functionnalized 4-vinylcyclohexene derivatives, substituted with electron-withdrawing or -donating groups on the exocyclic double bond, have been isomerized by pentacarbonyliron, under thermodynamic control with heating, into a mixture of conjugated cyclohexadiene tricarbonyliron complexes, of which the 2-substituted derivative is the predominant.When ferrous chloride is used as the co-catalyst, the isomerisation proceeds under kinetic control to give the 1-substituted cyclohexadienetricarbonyliron complex as the major derivative.Reaction mechanisms, have been proposed for these isomerisation processes, which provide a new selective route to such derivatives.The formation of η4-1,4-cyclohexadienetricarbonyl complexes as intermediates has been excluded, and it is shown that the thermal isomerisation proceeds via η2-complexes that are formed by successive 1,3-hydrogen shifts.
