- ?-CYCLOHEXADIENONE DERIVATIVES OF RHODIUM(I) ACETYLACETONATE. CRYSTAL AND MOLECULAR STRUCTURE OF RHODIUM (η4-4-METHYL-4-exo-TRICHLOROMETHYL-2,5-CYCLOHEXADIENE-1-ONE)(PENTANE-O,O'-2,4-DIONATE)
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By means of the ligand exchange reactions of Rh(acac)(C2H4)2 (VII) with para-semiquinoid cyclohexadienone ligands (4,4-dimethyl-(VI), 4-methyl-4-n-butyl-(IX), 4-methyl-4-dichloromethyl-(X), 4-methyl-4-trichloromethyl-(XIII)-cyclohexadiene-2,5-ones-1) the
- Nikanorov, V. A.,Rozenberg, V. I.,Yanovsky, A. I.,Struchkov, Yu. T.,Reutov, O. A.,et al.
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- Electrochemical reduction of 4-methyl-4-(trichloromethyl)cyclohexa-2,5- dien-1-one
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The properties of 4-methyl-4-(trichloromethyl)cyclohexa-2,5-dien-1-one which contains the trichloromethyl substituent at a quaternary carbon atom have been studied by cyclic voltammetry, rotating disk electrode voltammetry, and preparative electrolysis. Reductive dehalogenation involves initial two-electron reductive elimination of one of the geminal chlorine atoms followed by consecutive addition of proton, simultaneous elimination of the two residual halogen atoms to form carbene, and rearrangement of cyclohexadienone into the corresponding 4-methylcyclohepta-2,4,6-trien-1-one.
- Moiseeva,Gavrilova,Vykhodtseva,Nikolaeva,Krut'Ko,Beloglazkina
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- Dialkyl-substituted dithianes and pesticidal compositions
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The present invention provides compounds of the formula (I): STR1 wherein m and n are independently selected from 0, 1 or 2, STR2 R is selected from hydrogen, methyl or ethyl; R1 is selected from C1-4 hydrocarbyl substituted by one to five halo atoms, and a group --C C--R9 wherein R9 is a group S(O)w --R10 wherein R10 is trifluoromethyl, methyl or ethyl and w is 0, 1 or 2 or R9 is a C3-5 aliphatic group or an aliphatic group containing up to 5 carbon atoms atoms substituted by C1-4 alkoxy, C2-6 alkoxyalkoxy, C1-8 acyloxy, halo or hydroxy, a group COR11 wherein R11 is hydrogen, C1-4 alkyl, C1-4 alkoxy or a group NR12 R13 wherein R12 and R13 are independently selected from hydrogen, methyl or ethyl, or R9 is SiR14 R15 R16 wherein R14 to R16 are the same or different and each is a C1-4 aliphatic group or R14 and R15 are C1-4 aliphatic groups and R16 is a phenyl group; R2, R3, R7 and R8 are independently selected from hydrogen, methyl or halo; R4a and R4b, R6a and R6b are independently selected from hydrogen, C1-3 alkyl, C2-3 alkenyl or alkynyl each being optionally substituted by halo, cyano or C1-4 alkoxy; cyano, halo or a group COR 11a wherein R11a is hydrogen, C1-4 alkoxy, C1-4 alkyl or a group NR12a R13a wherein R12a and R13a are independently selected from hydrogen, methyl or ethyl; R5a is a non-aromatic hydrocarbyl group containing up to seven carbon atoms, or phenyl each optionally substituted by cyano, halo, C1-4 alkyl, C1-4 haloalkyl, C3-4 cycloalkyl, C1-4 alkoxy or a group S(O)q R17 wherein q is 0, 1 or 2 and R17 is methyl or ethyl and R5b is hydrogen, hydroxy or C1-4 alkyl optionally substituted by alkoxy; and represents --CH--CH-- or --C=C-- which are useful pesticides, processes for their preparation, pesticidal formulations containing them and their use in the control or prevention of pest infestation.
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- Process for selectively producing para-substituted derivatives of phenols
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By reacting, using as a catalyst a modified or unmodified cyclodextrin, a phenol compound with a haloform in the presence of an alkali metal hydroxide, while maintaining the molar ratio of the cyclodextrin to the haloform at 0.5 to 10, a substituent group
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- Selective Syntheses Using Cyclodextrin as Catalyst. 1. Control of Orientation in the Attack of Dichlorocarbene at Phenolates
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4-Hydroxybenzaldehydes, 2,4-dihydroxybenzaldehyde, and 4-(dichloromethyl)-2,5-cyclohexadienones were synthesized in virtually 100percent selectivities and high yields from the corresponding phenols and chloroform in alkaline aqueous solutions by using α- or β-cyclodextrin (α- or β-CD) as catalyst.The regulation of the molar ratio of chloroform to CD below unity throughout the reaction time, by controlling the rate of addition of chloroform, was definitely required to attain high selectivity.Under these conditions, dichlorocarbene, prepared in situ from chloroform and sodium hydroxide, attacked overwhelmingly at the para carbon of phenols with almost perfect suppression of the reaction at the ortho carbon.The structure of the ternary molecular complex composed of β-CD, chloroform, and phenol, formed in the reaction mixture for the selective synthesis of 4-hydroxybenzaldehyde, was determined by NMR spectroscopy.The selective catalysis by CDs was attributed to the regulation of molecular conformation of phenols with respect to chloroform, and thus to dichlorocarbene, in the ternary complex.
- Komiyama, Makoto,Hirai, Hidefumi
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p. 2018 - 2021
(2007/10/02)
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- TRAPPING OF REACTIVE INTERMEDIATES IN DIENONE PHOTOCHEMISTRY BY AMINES
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Irradiation of 4-methyl-4-trichloromethyl-2,5-cyclohexadienones in amine solvents leads to the formation of the corresponding dichloromethyl cyclohexadienones by a process involving electron transfer from the amines to zwitterion intermediates.
- Brisimitzakis, Angelo C.,Schuster, David I.
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p. 4535 - 4538
(2007/10/02)
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- PHOTOCHEMICAL ELECTRON TRANSFER REACTIONS OF 4-TRICHLOROMETHYL-4-METHYL-2,5-CYCLOHEXADIEN-1-ONES
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Ultraviolet irradiation of the title compounds in amine solvents results in transformations attributed to initial formation of radical ions by electron transfer, the quantum efficiency of reaction depending on the ionization potential of the amine.
- Schuster, David I.,Brisimitzakis, Angelo C.
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p. 4531 - 4534
(2007/10/02)
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