Asymmetric catalytic Mannich reactions catalyzed by urea derivatives: enantioselective synthesis of beta-aryl-beta-amino acids.
Highly enantioselective addition reactions between silyl ketene acetals and N-Boc aldimines are catalyzed by the thiourea-based catalyst 1c. Extraordinary scope is observed in this methodology with regard to the imine substrate, with aryl and heteroaromatic derivatives generally affording nearly quantitative yields of beta-amino ester product in up to 98% enantioselectivity.
Wenzel
Anna G
AG
Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
Jacobsen
Eric N
EN
D000080:Acetals / Q000737:chemistry; D000596:Amino Acids / Q000138:chemical synthesis*; D002384:Catalysis; D005563:Formic Acid Esters / Q000737:chemistry; D013237:Stereoisomerism; D013890:Thiourea / Q000031:analogs & derivatives* / Q000737:chemistry
D000080:Acetals; D000596:Amino Acids; D005563:Formic Acid Esters; C000345:t-butyloxycarbonyl group; D013890:Thiourea