Iron-catalysed oxidation of N,N-(dialkyl)acylmethylamines with molecular oxygen in the presence of either 2-mercaptoethanol or sodium sulphide

Air-oxidation of N,N-(dialkyl)acylmethylamines (1a–f) using a catalytic amount of [{Fe(salen)}2O][salen =N,N′-bis(salicylidene)ethylenediaminato] in the presence of 2-mercaptoethanol gave the corresponding α-oxo amides (2a–f) in moderate to good yields. With sodium sulphide in place of the thiol α-oxo thioamides (9a–f) were obtained as the predominant products.