Chiral phosphoramide-catalyzed, enantioselective, directed cross-aldol reactions of aldehydes
AUTOR(ES)
Denmark, Scott E.
FONTE
National Academy of Sciences
RESUMO
Catalytic, enantioselective, directed cross-aldol reactions of aldehydes are described. The addition of isobutyraldehyde trichlorosilyl enolate 2 to various aldehydes in the presence of 10 mol % bisphosphoramide 4 provides aldol products in high yields with moderate to good enantioselectivities. The reaction works well with a wide range of aromatic, olefinic, and aliphatic aldehydes. Enantioselectivities are highly dependent on the electronic nature of the aldehyde substituent. Hammett studies reveal that enantioselectivity increases as aldehydes become either more electron rich or more electron poor.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=397401Documentos Relacionados
- Enantioselective direct aldol reactions catalyzed by l-prolinamide derivatives
- Novel chiral ionic liquid (CIL) assisted selectivity enhancement to (L)-proline catalyzed asymmetric aldol reactions
- Metal-catalyzed asymmetric aldol reactions
- Air-stable, storable, and highly efficient chiral zirconium catalysts for enantioselective Mannich-type, aza Diels–Alder, aldol, and hetero Diels–Alder reactions
- Enantioselective Diels–Alder reactions catalyzed by hydrogen bonding