ISSN:
0894-3230
Keywords:
Organic Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Rate constants (k2) were determined for the reduction of 1-benzyl-3-cyanoquinolinium ion by phosphonate dianion in mixed solvents consisting of propan-2-ol and water. The reduction product was mostly 1-benzyl-3-cyano-1,4-dihydroquinoline with a trace of the 1,2-isomer. The solvent properties were varied by increasing the fraction of water in the mixed solvent, which increases the polarity of the solvent. Increasing the proportion of alcohol makes the solvent a better electron pair donor. The higher fraction of propan-2-ol in the mixed solvent gives rise to a substantial increase in k2. A quantitative comparison of the solvent effect on this reaction with the solvent effects on related reactions suggests a solvent Brønsted α value of 0·45. This suggests that the PO3- unit of the transition state interacts only weakly with the solvent although the final oxidized product is phosphate.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/poc.610050508
