{'fraction_non_alphanumeric': 0.025936599423631124, 'fraction_numerical': 0.005763688760806916, 'mean_word_length': 5.165680473372781, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Kinetics and mechanism of the oxidation of some α-amino acids by butyltriphenylphosphonium dichromate

The oxidation of a series of nine α-amino acids by butyltriphenylphosphonium dichromate (BTPPD) 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 hydrogen ion. The oxidation of perdeuterioglycine showed the absence of a kinetic isotope effect (k H /k D = 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.