1462366-75-1Relevant articles and documents
Pseudoephedrine-Directed Asymmetric α-Arylation of α-Amino Acid Derivatives
Atkinson, Rachel C.,Fernández-Nieto, Fernando,Mas Rosell?, Josep,Clayden, Jonathan
supporting information, p. 8961 - 8965 (2015/08/03)
Available α-amino acids undergo arylation at their α position in an enantioselective manner on treatment with base of N′-aryl urea derivatives ligated to pseudoephedrine as a chiral auxiliary. In situ silylation and enolization induces diastereoselective migration of the N′-aryl group to the α position of the amino acid, followed by ring closure to a hydantoin with concomitant explulsion of the recyclable auxiliary. The hydrolysis of the hydantoin products provides derivatives of quaternary amino acids. The arylation avoids the use of heavy-metal additives, and is successful with a range of amino acids and with aryl rings of varying electronic character.