BETAINES DERIVED FROM AMINO AND HYDRAZINO ACIDS AS PHASE-TRANSFER CATALYSTS

Betaines derived from α-, β- and γ-amino acids (obtained by alkylation of the corresponding amino acids with O-methyl-N.N'- diisopropylisourea) as well as β-hydrazino acids (prepared by de- hydrohalogenative hydrolysis of methyl 3-(2-a1ky1-2,2-dimethy1hydrazinium) propionate halides catalyse typical phase transfer reactions (dichlorocyclopropanation of styrene, N-formylation of pyrrolidine, dehydration of benzamide and phenylacetamide, Williamson synthesis of benzyl propyl ether, addition of ethoxycarbonylnitrene to 2,3-dimethylbutene-2. In most cases, the activity of zwitterionic salts is at least similar to that of typical phase transfer catalysts (tetra- alkylammonium salts). The mechanism of the catalytic action of betaines 1s proposed. © 1990.