Phosphonium salts. I. The alkaline hydrolysis of some bis-phosphonium salts

1969 ◽  
Vol 22 (7) ◽  
pp. 1385 ◽  
Author(s):  
JJ Brophy ◽  
MJ Gallagher
Keyword(s):  
Kinetic Study ◽  
Phosphine Oxide ◽  
Alkaline Hydrolysis ◽  
Phosphorus Atom ◽  
Phosphonium Salt ◽  
P System ◽  
Phosphonium Salts ◽  
Partial Explanation ◽  
Reaction Proceeds ◽  
Hydrolysis Of

Ethane- and ethene-1,2-bisphosphonium salts are cleaved by alkali into a phosphine and a phosphine oxide with loss of the two-carbon bridge. When the phosphorus atom carries benzyl substituents, loss of the benzyl groups is competitive with loss of the bridge. ��� Based on a kinetic study, a synchronous mechanism, analogous to the alkaline hydrolysis of acyclic monophosphonium salts, is proposed to account for the fragmentation. ��� With 6-membered 1,4-diphosphonio heterocyclic salts the nature of the products is dependent on whether alkali or phosphonium salt is present in excess. With an excess of alkali a synchronous mechanism again appears to operate, while with an excess of salt the reaction proceeds stepwise and without loss of the bridge. A partial explanation of these facts is advanced in terms of non-bonded interactions in the intermediate phosphoranes. ��� The synchronous reaction appears to be favoured by coplanarity of the P-C-C-P system.

Rapid Betaine Collapse in the Reactions of Six-Membered Ring Cyclic Phosphines with Styrene Oxide, and Rates of Alkaline Hydrolysis of Related Cyclic Phosphonium Salts

1979 ◽  
Vol 34 (8) ◽  
pp. 1112-1115
Author(s):  
David W . Allen ◽  
Barrie G. Hutley ◽  
A. Christopher Oades
Keyword(s):  
Phosphine Oxide ◽  
Alkaline Hydrolysis ◽  
Styrene Oxide ◽  
Membered Ring ◽  
Phosphonium Salts ◽  
Alternative Routes ◽  
Hydrolysis Of ◽  
Vinylphosphonium Salts

The reactions of a series of six-membered ring cyclic phosphines (10-phenylphenoxaphosphine, 10-phenylphenothiaphosphine, and the related sulphone) with styrene oxide in ethanol result in the formation of styrene and the corresponding cyclic phosphine oxide, indicating that betaine collapse is rapid compared to alternative routes involving the formation of vinylphosphonium salts. This conclusion is supported by studies of the rates of alkaline hydrolysis of the related methylphosphonium salts which give rise to ringopened products. These salts undergo hydrolysis significantly faster than the acyclic salt methyltriphenylphosphonium iodide, due to the electron-withdrawing effect of the oxygen, sulphur or sulphone grouping in the six-membered ring

Kinetic Study of Hydrolysis of Benzoates. Part XXVI. Variation of the Substituent Effect with Solvent in Alkaline Hydrolysis of Substituted Alkyl Benzoates

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1557-1570 ◽  
Author(s):  
Vilve Nummert ◽  
Mare Piirsalu ◽  
Ilmar A. Koppel
Keyword(s):  
Kinetic Study ◽  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Substituent Effect ◽  
Substituent Effects ◽  
Alkyl Substituent ◽  
Solvent Parameters ◽  
Substituent Constants ◽  
Hydrolysis Of ◽  
Main Factor

The second-order rate constants k2 (dm3 mol-1 s-1) for the alkaline hydrolysis of substituted alkyl benzoates C6H5CO2R have been measured spectrophotometrically in aqueous 0.5 M Bu4NBr at 50 and 25 °C (R = CH3, CH2Cl, CH2CN, CH2C≡CH, CH2C6H5, CH2CH2Cl, CH2CH2OCH3, CH2CH3) and in aqueous 5.3 M NaClO4 at 25 °C (R = CH3, CH2Cl, CH2CN, CH2C≡CH). The dependence of the alkyl substituent effects on different solvent parameters was studied using the following equations:      ∆ log k = c0 + c1σI + c2EsB + c3∆E + c4∆Y + c5∆P + c6∆EσI + c7∆YσI + c8∆PσI     ∆ log k = c0 + c1σ* + c2EsB + c3∆E + c4∆Y + c5∆P + c6∆Eσ* + c7∆Yσ* + c8∆Pσ* .  ∆ log k = log kR - log kCH3. σI and σ* are the Taft inductive and polar substituent constants. E, Y and P are the solvent electrophilicity, polarity and polarizability parameters, respectively. In the data treatment ∆E = ES - EH2O , ∆Y = YS - YH2O , ∆P = PS - PH2O were used. The solvent electrophilicity, E, was found to be the main factor responsible for changes in alkyl substituent effects with medium. When σI constants were used, variation of the polar term of alkyl substituents with the solvent electrophilicity E was found to be similar to that observed earlier for meta and para substituents, but twice less when σ* constants were used. The steric term for alkyl substituents was approximately independent of the solvent parameters.

Kinetic study on the alkaline hydrolysis of Co(NH3)5O2C2Cl32+ and Co(NH3)5O2C2Cl2H2+

1967 ◽  
Vol 6 (2) ◽  
pp. 379-382 ◽  
Author(s):  
Neil S. Angerman ◽  
Robert B. Jordan
Keyword(s):  
Kinetic Study ◽  
Alkaline Hydrolysis ◽  
Hydrolysis Of

Kinetic study of microwave-assisted alkaline hydrolysis of Jatropha curcas oil

2016 ◽  
Author(s):  
Nur’aini Raman Yusuf ◽  
Ruzaimah Nik Mohamad Kamil ◽  
Suzana Yusup
Keyword(s):  
Kinetic Study ◽  
Alkaline Hydrolysis ◽  
Jatropha Curcas ◽  
Jatropha Curcas Oil ◽  
Microwave Assisted ◽  
Hydrolysis Of
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