Palladium-catalyzed synthesis of enantiomerically pure alpha-substituted allylboronic esters and their addition to aldehydes.
Tartrate-derived boronic esters 2 can be subjected to palladium-catalyzed carbonyl allylations with SnCl(2) to obtain enantiomerically pure alpha-substituted allylboronic esters 8 and 9. The reaction proceeds regioselectively and with high, simple diastereoselectivity to form anti-products. Their addition to aldehydes yields enantiomerically enriched homoallylic alcohols 17 and 18, respectively. Synthesis, characterization, and a mechanistic rational is presented here.
Fernández
Enrique
E
Institut für Bioorganische Chemie der Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich, Germany.
Pietruszka
Jörg
J
Frey
Wolfgang
W
D000447:Aldehydes / Q000737:chemistry*; D001897:Boronic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D018360:Crystallography, X-Ray; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism
D000447:Aldehydes; D001897:Boronic Acids; D004952:Esters; D009942:Organometallic Compounds; D010165:Palladium