title: Scalable organocatalytic asymmetric Strecker reactions catalysed by a chiral cyanide generator.
abstract: The Strecker synthesis is one of the most facile methods to access racemic α-amino acids. However, feasible catalytic asymmetric Strecker reactions for the large-scale production of enantioenriched α-amino acids are rare. Here we report a scalable catalytic asymmetric Strecker reaction that uses an accessible chiral variant of oligoethylene glycol as the catalyst and KCN to generate a chiral cyanide anion. Various α-amido sulphone substrates (alkyl, aryl and heteroaryl) can be transformed into the optically enriched Strecker products, α-aminonitriles, with excellent yields and enantioselectivities. Moreover, the robust nature of the catalyst enables a 'one-pot' synthesis of enantiomerically pure α-amino acids starting from α-amido sulphones and simple catalyst recycling. These features can make this protocol easily adaptable to the practical synthesis of unnatural α-amino acids.
authors.affiliation: Department of Chemistry, Sungkyunkwan University, 300 Cheoncheon, Jangan, Suwon, Gyeonggi 440-746, Korea.
authors.forename: Hailong
authors.initials: H
authors.lastname: Yan
authors.forename: Joong
authors.initials: J
authors.lastname: Suk Oh
authors.forename: Ji-Woong
authors.initials: JW
authors.lastname: Lee
authors.forename: Choong
authors.initials: C
authors.lastname: Eui Song