Über organische Katalysatoren. IV. Die Decarboxylierung der Phenylglyoxylsäure und Brenztraubensäure Mit 5 Figuren im Text

Abstract

Phenylglyoxylsäure läßt sich mit primären Aminen und Aminosäuren bei 137° katalytisch in Benzaldehyd und Kohlendioxyd spalten. Als Zwischenstoffe entstehen dabei Iminoderivate der Phenylglyoxylsäure. Die aktivsten Katalysatoren sind die α‐Amino‐säuren. Stets kommt die Katalyse infolge von Nebenreaktionen vorzeitig zum Stehen.

Decarboxylation of a keto acids

“…Thermal Decarboxylation Langenbeck and Hutschenreuter (5) found that heating pyruvic acid under an atmosphere of nitrogen for 15 min at 137 °C produced no acetaldehyde (as the p-nit.rophenylhydrazone). The pyrolysis of benzoylformic acid (phenylglyoxcylic acid, 1, R = C6H5) under an atmosphere of carbon dioxide or of nitrogen at temperatures between 250 °C and 300 °C was investigated by Hurd and Raterink (6), who found that the identifiable products were carbon monoxide (20%), carbon dioxide (50%), benzaldehyde (~22%) and benzoic acid (~55%).…”

β- and σ-Amino acids (2,3- and 3,4-trans-CHA) as catalysts in Knoevenagel condensation and asymmetric aldol reactions

“…3 Additionally, it was noted that primary amines catalyze the decarboxylation of α-ketocarboxylic acids to produce the corresponding aldehydes. 4,5 In 1953, Prout reported the catalytic effect of L-and D-amino acids as well as the catalytic behavior of β-amino acids in Knoevenagel condensations; good yields were achieved using β-alanine as a catalyst. 6 In the 1970s, L-proline was introduced as a catalyst in the asymmetric Robinson annulation reaction.…”