ABSTRACT
The 'one-pot' stereoselective conversion of N-(4-nitrobenzene)sulfonyl-alpha-amino acid tert-butyl esters into the corresponding N-alkyl-alpha-(4-nitrophenyl)-alpha-amino esters has been realized through N-alkylation of the starting amido esters, followed by N-C(alpha) migration of the p-nitrophenyl group and the loss of sulfur dioxide; the asymmetric induction is determined by an intermediate non-racemic enolate, without the need of an external source of chirality.
Subject(s)
Amino Acids/chemistry , Alkylating Agents/chemistry , Esters/chemistry , Pargyline/analogs & derivatives , Pargyline/chemistry , Stereoisomerism , Sulfones/chemistryABSTRACT
Polyfunctionalized benzo[d]sultams 7 and 8, which contain an alpha-amino acid unit, have been synthesized from the corresponding open chain (pentafluorobenzene)sulfonamides 4 by complementary solid-liquid phase transfer catalysis (SL-PTC) and homogeneous protocols. The cyclization step proceeds through the intramolecular nucleophilic displacement of an aromatic fluorine atom.