Synthesis of both enantiomers of hemiesters by enantioselective methanolysis of meso cyclic anhydrides catalyzed by alpha-amino acid-derived chiral thioureas.
Both ureas and thioureas derived from L- or D-valine act as bifunctional organocatalysts able to induce the enantioselective alcoholysis of mono-, bi-, and tricyclic meso anhydrides. The desymmetrization occurs in near quantitative yields and excellent enantiomeric ratios (up to >99:<1) under low catalyst loading. Both enantiomers of the hemiesters can be directly obtained by changing the configuration of the catalyst.
Manzano
Rubén
R
Instituto CINQUIMA and Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Valladolid, Dr. Mergelina s/n, 47011-Valladolid, Spain.
Andrés
José M
JM
Muruzábal
María-Dolores
MD
Pedrosa
Rafael
R
D000596:Amino Acids / Q000737:chemistry*; D000812:Anhydrides / Q000737:chemistry*; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D004952:Esters; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008697:Methane / Q000737:chemistry*; D013237:Stereoisomerism; D013890:Thiourea / Q000737:chemistry*
D000596:Amino Acids; D000812:Anhydrides; D004952:Esters; D013890:Thiourea; D008697:Methane