title: Asymmetric strecker synthesis of alpha-amino acids via a crystallization-induced asymmetric transformation using (R)-phenylglycine amide as chiral auxiliary.
abstract: [reaction: see text]. Diastereoselective Strecker reactions based on (R)-phenylglycine amide as chiral auxiliary are reported. The Strecker reaction is accompanied by an in situ crystallization-induced asymmetric transformation, whereby one diastereomer selectively precipitates and can be isolated in 76-93% yield and dr > 99/1. The diastereomerically pure alpha-amino nitrile obtained from pivaldehyde (R1 = t-Bu, R2 = H) was converted in three steps to (S)-tert-leucine in 73% yield and >98% ee.
authors.affiliation: DSM Research Life Sciences-Organic Chemistry and Biocatalysis, P.O. Box 18, 6160 MD Geleen, and Syncom B.V., Kadijk 3, 9747 AT Groningen, The Netherlands.
authors.forename: W H
authors.initials: WH
authors.lastname: Boesten
authors.forename: J P
authors.initials: JP
authors.lastname: Seerden
authors.forename: B
authors.initials: B
authors.lastname: de Lange
authors.forename: H J
authors.initials: HJ
authors.lastname: Dielemans
authors.forename: H L
authors.initials: HL
authors.lastname: Elsenberg
authors.forename: B
authors.initials: B
authors.lastname: Kaptein
authors.forename: H M
authors.initials: HM
authors.lastname: Moody
authors.forename: R M
authors.initials: RM
authors.lastname: Kellogg
authors.forename: Q B
authors.initials: QB
authors.lastname: Broxterman
mesh_terms: D000577:Amides / Q000737:chemistry*; D000596:Amino Acids / Q000138:chemical synthesis*; D003460:Crystallization; D018360:Crystallography, X-Ray; D005998:Glycine / Q000031:analogs & derivatives / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D000577:Amides; D000596:Amino Acids; C021316:N-phenylglycine; D005998:Glycine