Pure Appl. Chem., 2006, Vol. 78, No. 2, pp. 409-414
doi:10.1351/pac200678020409
Dual Lewis acid - Lewis base activation in enantioselective additions to aldehydes*
Erica Wingstrand, Stina Lundgren, Maël Penhoat, and Christina Moberg
Department of Chemistry, Organic Chemistry, Royal Institute of Technology, SE 100 44 Stockholm, Sweden
Abstract:
Reaction of benzaldehyde with ethyl cyanoformate in the presence of Lewis acidic Ti(IV) complexes of bispyridylamide or salen ligands and Lewis basic amines affords the O-alkoxycarbonylated cyanohydrin. In the presence of the salen-based catalytic system, acetyl cyanide can also be added to benzaldehyde, providing a highly enantioselective direct route to the O-acetylated cyanohydrin.
Keywords: bispyridylamide; cyanohydrin; Lewis acid; Lewis base; salen; titanium.
*Pure Appl. Chem. 78, 197-523. An issue of reviews and research papers based on lectures presented at the 13th IUPAC International Symposium on Organometallic Chemistry Directed Towards Organic Synthesis (OMCOS-13), Geneva, Switzerland, 17-21 July 2005.