Thermodynamic and kinetic control over the oxidation mechanism of the natural vanadyl porphyrin series (DPEP)VO in methylene chloride: electrogeneration of an unusual dicationic species [(DPEP)VO]22+

2006 ◽  
Vol 30 (7) ◽  
pp. 997 ◽  
Author(s):  
Anass Doukkali ◽  
Ahmed Saoiabi ◽  
Mohamed Ferhat ◽  
Yves Mugnier ◽  
Alain Vallat ◽  
...  
Keyword(s):  
Methylene Chloride ◽  
Oxidation Mechanism ◽  
Kinetic Control ◽  
Vanadyl Porphyrin

The reaction of some propargyl alcohols with benzeneselenenyl chloride

1981 ◽  
Vol 59 (6) ◽  
pp. 927-934 ◽  
Author(s):  
Dennis G. Garratt ◽  
Pierre L. Beaulieu ◽  
Veronique M. Morisset
Keyword(s):  
Chloride Solution ◽  
Methylene Chloride ◽  
Kinetic Control ◽  
Methylene Chloride Solution ◽  
Propargyl Alcohols

The reaction of benzeneselenenyl chloride with twenty-two propargyl alcohols in methylene chloride solution is reported. Products of both Markownikoff and anti-Markownikoff regiochemistry are formed in an anti stereospecific manner. The regioselectivity or specificity is found to be very dependent upon the nature of the substituents geminal to the alcoholic moiety. In general the presence of bulky substituents geminal to the alcoholic moiety tend to favour formation of the anti-Markownikoff adduct under conditions of kinetic control. The Markownikoff adducts are found to be favoured thermodynamically.

Electrophilic cleavage of cyclopropanes. The areneselenenylation of tetracyclo[3.2.0.02,7.04,6]heptane (quadricyclene)1,2

1980 ◽  
Vol 58 (10) ◽  
pp. 1005-1013 ◽  
Author(s):  
Pierre L. Beaulieu ◽  
Veronique M. Morisset ◽  
Dennis G. Garratt
Keyword(s):  
Methylene Chloride ◽  
Cyclopropane Ring ◽  
Bond Cleavage ◽  
Second Order ◽  
Ring Cleavage ◽  
Kinetic Control ◽  
First Order ◽  
And Inversion

The reaction of benzeneselenenyl chloride with tetracyclo[3.2.0.02,7.04,6]heptane (quadricyclene) yields, under conditions of kinetic control, adducts of both 1,3- and conjugative 1,6-addition, the latter being formed preferentially. Electrophilic cleavage of the cyclopropane ring occurs by both retention and inversion of configuration. In agreement with the known propensity for bond cleavage in this system only the C5—C6 and/or the C1—C7 bonds are broken. The rate of cyclopropane ring cleavage is found to follow second order kinetics, first order in quadricyclene and first order in selenenyl chloride; kobs = 1850 vs. 12 300 dm3 mol−1 s−1 for bicyclo[2.2.1]hepta-2,5- diene at 24.5 °C in methylene chloride solvent. The use of nucleophilic solvents such as HOAc, CH3OH, and CH3CN gives products of solvent-incorporation, preferentially via 1,3-addition.

Wet Air Oxidation of Low Molecular Weight Organic Acids

1973 ◽  
Vol 8 (1) ◽  
pp. 224-236 ◽  
Author(s):  
P.E.L. Williams ◽  
D.C. Day ◽  
R.R. Hudgins ◽  
P.L. Silveston
Keyword(s):  
Propionic Acid ◽  
Butyric Acid ◽  
Oxidation Mechanism ◽  
Equation Model ◽  
Low Molecular Weight ◽  
Kinetic Control ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
High Yields ◽  
Control Regime

Abstract Wet air oxidation is a process for the oxidation of organic matter dissolved or suspended in water. It operates from 300 to 600 F, usually at pressures of 1000 to 1800 psia. The process is not well understood. This paper reports a kinetic study using propionic and butyric acids. Our research has been directed towards three objectives: identification of the kinetic-control regime; development of a rate equation model, and investigation of the oxidation mechanism. Most of the work was performed using propionic acid. Results with this compound appears to be confirmed by studies using butyric acid. With vigorous agitation, the reaction is kinetically controlled below 550°F and is homogeneous in the aqueous phase. Oxygen attack at the α carbon is suggested by the data. This would account for the high yields of acetic acid. This slowly oxidized acid forms via acetaldehyde. A power law rate expression was developed for the oxidation of propionic acid. Work with butyric acid supports the propionic acid results.

The nonstereospecific addition of benzeneselenenyl chloride to 3,4-dihydro-2H-pyran

1978 ◽  
Vol 56 (16) ◽  
pp. 2184-2187 ◽  
Author(s):  
Dennis G. Garratt
Keyword(s):  
Good Yield ◽  
Methylene Chloride ◽  
Kinetic Studies ◽  
Kinetic Control ◽  
Diphenyl Diselenide ◽  
Thermodynamic Control

The addition of benzeneselenenyl chloride to 3,4-dihydro-2H-pyran in methylene chloride at 25 °C gives 65% of the trans and 35% of the cis Markownikoff adduct: 2-chloro-3-phenylseleno-tetrahydropyran under conditions of kinetic control. The above reaction was observed to be reversible, the adducts subsequently reacting with the benzeneselenenyl chloride under conditions similar to those used for the reaction with 3,4-dihydro-2H-pyran to give diphenyl diselenide and 2,3-dichlorotetrahydropyran in good yield. There was no evidence for the formation of 3-chloro-2-phenylselenotetrahydropyran under conditions of either kinetic or thermodynamic control. Kinetic studies support a mechanism involving a seleniranium ion that opens to an oxacarbonium ion before the product determining step.

Electrophilic additions to strained alkenes. II. The reaction of benzeneselenenyl chloride with tricyclo[4.2.2.02,5]deca-3,7-diene derivatives

1980 ◽  
Vol 58 (22) ◽  
pp. 2329-2339 ◽  
Author(s):  
Dennis G. Garratt ◽  
M. Dominic Ryan ◽  
Ann Kabo
Keyword(s):  
Acetic Acid ◽  
Methylene Chloride ◽  
Solvent System ◽  
Major Product ◽  
Kinetic Control ◽  
Solvent Systems ◽  
Electrophilic Additions ◽  
Strained Alkenes ◽  
Derivatives Of

The reactions of benzeneselenenyl chloride with three derivatives of tricyclo[4.2.2.02,5]deca-3,7-diene have been investigated in four solvent systems: methylene chloride, acetic acid, acetic acid/LiClO4, and methanol. Under conditions of kinetic control only products of exo–anti attack upon the cyclobutene moiety are isolable when the solvent system is methylene chloride or acetic acid. This observation also holds in acetic acid/LiClO4 except in the case of dimethyl tricyclo[4.2.2.02,5]deca-3,7,9-triene-7,8-dicarboxylate where the major product is that of cross-bonding with solvent incorporation. In methanol products of solvent incorporation, transannular cross-bonding and lactonization (where possible) are observed. A general mechanistic scheme is proposed to account for these observations in accord with earlier results for the analogous arenesulphenylations.

High Temperature Oxidation Mechanism of Ti3SiC2-64vol%SiC Ceramics

2009 ◽  
Vol 24 (4) ◽  
pp. 821-826
Author(s):  
Hui-Yi TANG ◽  
De-Gui ZHU ◽  
Bo LIU ◽  
Hong-Liang SUN
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Oxidation Mechanism ◽  
Temperature Oxidation ◽  
Sic Ceramics
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