Synthesis and application of oxadiazines as chiral ligands for the enantioselective addition of diethylzinc to aldehydes
摘要:
A series of oxadiazines derived from L-phenylalanine bearing phenolic substituents have been synthesized in a multistep one pot process This process involves the reaction of a mixed anhydride with a beta-hydrazino alcohol methanesulfonylation of the alcohol moiety and base induced cyclization The resultant oxadiazines were employed in the asymmetric addition of diethylzinc to aldehydes (C) 2010 Elsevier Ltd All rights reserved
Synthesis, reactivity and conformational stability of an l-phenylalanine derived oxadiazinanone
摘要:
An L-phenylalanine derived oxadiazinanone bearing an isopropyl group at the N-4-position was prepared and acylated with either hydrocinnamoyl or propanoyl chloride. These oxadiazinanones were utilized in titanium-mediated asymmetric aldol reactions with aromatic and aliphatic aldehydes. The diastereoselectivities observed from these reactions ranged from fair to very good and suggested that the N-4-isopropyl-L-phenylalanine based oxadiazinanones are conformationally and configurationally stable at the N-4-nitrogen. (c) 2006 Elsevier Ltd. All rights reserved.