New Chiral Catalysts Containing N,O-Heterocycles Derived from Chiral Amino Alcohols

✍ Scribed by Olga Juanes; Juan Carlos Rodriguez-Ubis; Ernesto Brunet; Helmut Pennemann; Michael Kossenjans; Jürgen Martens

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 483 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199912)1999:12<3323::aid-ejoc3323>3.0.co;2-w

✦ Synopsis

The enantioselectivity exerted by a new series of chiral phenylpropan-1-ol. Molecular mechanics calculations suggested that the production of the R alcohol may be catalysts containing N,O-heterocycles of different sizes has been checked in the addition of diethylzinc to benzaldehyde, explained by a mechanism similar to that described by Noyori, in which ZnEt 2 interacts solely with the N-C-C-OH which was used as a model reaction. The catalysts were derived from natural amino acids, following a relatively fragment, whereas the formation of the S enantiomer needed the direct participation of the lateral chain of the parent simple procedure, and in several cases excellent ee values were obtained. The results were complementary since ee's amino acid and the N,O-heterocycle. ranged from 98% (R) to 94% (S) excesses of the final 1ize the observed enantioselection by molecular mechanics [a] Departamento de Quı ´mica Orga ´nica. Facultad de Ciencias, C-I. Universidad Auto ´noma Madrid, group into its ethyl ester. Treatment of the latter with the E-