Kinetics and mechanism of the oxidation of some α-amino acids by butyltriphenylphosphonium dichromate

Main Authors: Dinesh Panday, K. M. Dilsha, Seema Kothari
Format: Article Journal
Bahasa: eng
Terbitan: , 2009
Subjects:
Online Access: https://zenodo.org/record/5814832
Daftar Isi:
  • Department of Chemistry, J. N. V. University, Jodhpur-342 005, Rajasthan, India E-mail : seema@goraexporrs.com Manuscript received 15 December 2008. accepted 27 April 2009 The oxidation of a series of nine a-amino acids by butyltriphenylphosphonium dichromate (BTPPDJ in glacial acetic acid in the presence of toluene p-sulphonic acid (TsOH), leads to the formation of corresponding aldimines. The reactions are of first order with respect to BTPPD whereas the second order dependence is observed with respect to each the amino acid and hydro~en ion. The oxidation of perdeuterioglycine showed the absence of a kinetic isotope effect (kH/kD = 1.01 at 308 K). The reactions showed an excellent correlation with Taft's σ* substituent constants. the reaction constant being negative. The oxidation of alanine was studied in nineteen different organic solvents. The solvent effect was analyzed using Kamlet's and Swain's multiparametric equations. The analyses of solvent effect indicated the importance of the cation-solvating power of the solvent. Suitable mechanisms for the oxidation process are postulated.