Highly enantioselective carbonyl-ene reactions of 2,3-diketoesters: efficient and atom-economical process to functionalized chiral α-hydroxy-β-ketoesters.
Carbonyl-ene reactions of 2,3-diketoesters catalyzed by [Cu{(S,S)-tBu-box}](SbF6)2 [box=bis(oxazoline)] generate chiral α-functionalized α-hydroxy-β-ketoesters in up to 94% yield and 97% ee. The 2,3-diketoesters are conveniently accessed from the corresponding α-diazo-β-ketoester, and a catalyst loading as low as 1.0 mol% can be achieved.
Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742 (USA).
Phong M
PM
Truong
Peter Y
PY
Zavalij
Michael P
MP
Doyle
asymmetric catalysis; carbonyl-ene reaction; copper; ligand effects; synthetic methods