1077-10-7Relevant academic research and scientific papers
Carbon-13 NMR Spectra of DDT, its Analogues and Related Compounds
Freidlina, R. Kh.,Dostovalova, V. I.,Kuz'mina, N. A.,Chukovskaya, E. C.
, p. 133 - 138 (1981)
Carbon-13 NMR spectra of mono- and disubstituted aromatic compounds including DDT, its analogues, homologues, derivatives and certain model compounds have been studied.The Savitsky scheme of carbon chemical shifts in disubstituted benzenes is applicable to these compounds.The data obtained show that in mono- and disubstituted aromatic compounds containing two different substituents in the α- and β-positions of the side chain, the substituted ring carbon atom shifts follow the additivity rule and can be calculated from substituent increments.Mutual effects of substituents in the ring and in the side chains are analysed.The chlorine atoms in α-position to the phenyl ring give rise to an additive α-effect of about 25 ppm, as in perchloroalkanes.The influence of a β-chlorine atom in the side chain on the substituted carbon atom in the ring is, however, only 3 ppm as against the usual value of about 10 ppm for the β-effect in alkyl chains.Moreover, the first β-chlorine substituent has no noticeable influence on the substituted ring carbon chemical shift: the effect of 3 ppm is transferred to the para-carbon atom almost without attenuation.The ring substituted carbon atom signal shifts caused by the γ-effect of chlorine in the side chain are similar to those observed in aliphatic chains.The ortho-chlorine substituents shift the side chain α-carbon atom signal by 3.6-5.2 ppm to high field compared to para-chlorophenyl compounds.This is similar to the chlorine γ-effect in aliphatic chains.
BIMOLECULAR HOMOLYTIC SUBSTITUTION AT A CARBON ATOM IN ORGANOCOBALOXIMES. INTERRELATION OF KINETIC AND THERMODYNAMIC CHARACTERISTICS
Kondakov, D. Yu.,Dneprovskii, A. S.
, p. 1084 - 1091 (2007/10/02)
The absolute rate constants have been determined for the homolytic dissociation and the bimolecular homolytic substitution of an organocobalt grouping by trichloromethyl radicals in methyl-, hexyl-, and 1-phenylethylcobaloximes containing p-donor and r-donor axial ligands.The rate of homolytic substitution is determined by the dissociation energy of the cobalt-carbon bond and the spatial accessibility of the reaction center.At constant dissociation energy the reactivity series agrees with that observed in bimolecular nucleophilic substitution reactions.
Synthesis, Structure, and Catalytic Activity of μ-Alkylthio- and μ-Arylthio-μ-chloro-dicarbonylbis(tri-tert-butylphosphane)dirhodium Complexes
Schumann, Herbert,Cielusek, Guy,Jurgis, Stanislaw,Hahn, Ekkehardt,Pickardt, Joachim,et al.
, p. 2825 - 2838 (2007/10/02)
Tetracarbonyldi-μ-chloro-dirhodium (1) reacts with tri-tert-butylphosphane and alkyl or aryl trimethylsilyl sulfides 4 to give complexes tBu3)2Cl(SR)> (5a-i).The complexes 5h,i with the surface active trialkoxysilyl groups are fixed onto a fused silica support.The X-ray structural analyses of tBu3)2Cl(StBu)> (5c) and tBu3)2Cl(SC6H4Cl)> (5g) indicate a cis-configuration of the tri-tert-butylphosphane ligands.The new complexes catalyze the isomerization of 1-octen-3-ol (10) into 3-octanone (11), of 4-allylanisole (12) into cis- and trans-4-(1-propenyl)anisole (13), of trans-stilbene oxide (14) into desoxybenzoin (15), the transfer hydrogenation of α,β-unsaturated ketones by formic acid (16 -> 17), and the transfer hydrogenolysis of trihalomethyl compounds (18, 20) by halogen free alcohols.
