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Pseudoephedrine‐Directed Asymmetric α‐Arylation of α‐Amino Acid Derivatives
Author(s) -
Atkinson Rachel C.,
FernándezNieto Fernando,
Mas Roselló Josep,
Clayden Jonathan
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201502569
Subject(s) - chemistry , hydantoin , aryl , amino acid , enantioselective synthesis , hydrolysis , silylation , organic chemistry , stereochemistry , combinatorial chemistry , catalysis , biochemistry , alkyl
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.