Conversion of carbonimidodithioates to carbamates

Carbonimidodithioates derived from primary amines or α-amino acid esters have been converted to N-benzyloxycarbonyl derivatives under mild conditions by treatment first with sodium benzyl alcoholate and then with water. N-Benzyloxycarbonyl α-amino acids have been generated from the methyl esters by alkaline hydrolysis or from the allyl esters by Pd0-catalysed de-allylation

Unique zeolite-catalyzed synthesis of nitroketene S,N-acetals

Dimethyl carbonimidodithioates (4a-g, 7a-c) derived from various primary amines and amino acid esters [glycine, (L)-alanine and (L)-phenylalanine] have been condensed with nitromethane in the presence of the rare-earth exchanged zeolite RE(70%)Na Y to give the S,N-acetals (5a-g, 8a-c). Mercuric chloride catalyzed hydrolysis of these (8a-c) has led to the nitroacetyl derivatives (9a-c). The glycine derivative (7a) gives a dimeric product (11) when heated alone with the zeolite

Zeolites in organic syntheses: a novel route to functionalised ketene S,N-acetals

Active methylene compounds react with bis(methylthio)alkaneimines in the presence of a zeolite catalyst to give functionalised ketene S,N-acetals in good yields