4019-63-0Relevant academic research and scientific papers
Unravelling Lawesson's reagent: The structure of monomeric (4-methoxyphenyl)phosphine disulfide
Mardyukov, Artur,Niedek, Dominik,Schreiner, Peter R.
, p. 2715 - 2718 (2018)
We describe the isolation as well as IR and UV/Vis spectroscopic characterization of (4-methoxyphenyl)phosphine disulfide in argon matrices at 10 K. The title compound proved to be highly photolabile; irradiation with UV light (λ = 334 nm) led to rearrang
Hydrodehalogenation of 1,1-dibromocyclopropanes by Grignard reagents promoted by titanium compounds
Dulayymi, Juma'a R. Al,Baird, Mark S.,Bolesov, Ivan G.,Nizovtsev, Alexey V.,Tverezovsky, Viacheslav V.
, p. 1603 - 1618 (2007/10/03)
1,1-Dibromocyclopropanes are converted into the corresponding monobromocyclopropanes (as mixtures of stereoisomers where appropriate) by reaction with 1.0-1.3 mol equiv. of ethylmagnesium bromide and 2-10 mol% titanium isopropoxide for 90%). With ethylmagnesium bromide, the reaction occurs very slowly in the absence of catalyst; with methylmagnesium bromide, the reaction does occur in the absence of catalyst, but is only slightly promoted in the presence of titanium isopropoxide. Reactions with a number of other Grignard reagents are also discussed. In the case of phenethylmagnesium bromide, the major product containing the phenethyl-group is ethylbenzene, together with small amounts of styrene and ethyl 4-phenyl-2-butyl ether, a product of trapping of the solvent, ether. In other cases, relatively large amounts of a diether, formally derived by hydrogen ion adjacent to the ether oxygen followed by dimerisation, are isolated. No products were identified incorporating the cyclopropane and either the Grignard alkyl group or the solvent. Labelling studies indicate that the hydrogen introduced into the cyclopropane is not derived from either the α- or β-positions of the Grignard reagent. When the reduction is carried out with phenethylmagnesium bromide in d8-tetrahydrofuran both monobromides contain deuterium.
Thermodynamic Control of Regioselectivity in the Addition of Carbanions to (Arene)tricarbonylchromium Complexes
Kuendig, E. Peter,Desobry, Vincent,Simmons, Dana P.,Wenger, Eric
, p. 1804 - 1815 (2007/10/02)
The results of a study of question of kinetic or thermodynamic control of the addition of carbon nucleophiles to (arene)Cr(CO)3 complexes are presented. 2-Lithio-2-methylpropionitrile (1) is shown to add reversibly to (naphthalene)Cr(CO)3 (2), (5,8-dimeth
Model Systems for Cytochrome P450 Dependent Mono-oxygenases. Part 2. Kinetic Isotope Effects for the Oxidative Demethylation of Anisole and Anisole by Cytochrome P450 Dependent Mono-oxygenases and Model Systems
Smith, John R. Lindsay,Sleath, Paul R.
, p. 621 - 628 (2007/10/02)
Anisole, anisole, and anisole have been used as substrates to study the mechanisms of oxidative demethylation by model systems for the cytochrome P450 dependent mono-oxygenases.The size of the kinetic isotope effect for the demethylation can be used as a sensitive probe of the oxidation mechanism and as a method for classifying the chemical systems.By this procedure 17 mono-oxygenase models and four microsomal systems have been examined.Two systems involving iron(III) porphyrins and iodosylbenzene show large kinetic isotope effects comparable with those from the microsomal oxidations and can be considered as good models for the biological process.The remaining systems exhibit smaller isotope effects, kH/kD 1-3.4.Alternative mechanisms for the oxidative demethylations are discussed and the major routes are shown, to be either radical ipso-substitution or attack on the C-H bond of the methoxy-group.
