Synthesis of enantiomerically enriched amines by chiral ligand mediated addition of organolithium reagents to imines
作者:Sonia Arrasate、Esther Lete、Nuria Sotomayor
DOI:10.1016/s0957-4166(01)00344-5
日期:2001.8
The effect of the imine and ligand structure on the enantioselective addition or organolithiums to imines has been studied. Thus, (-)-sparteine-mediated additions or MeLi and or n-BuLi to p-anisidine derived phenylimine 1a afforded the corresponding amines with modest e.e.s. The use of bulkier or more reactive imines (naphthyl or toss I imines) resulted ill loss Of enantioselectivity. The best enantioinduction with this ligand,Nas obtained with enolizable imines 8 and 10. When bis(oxazolidines) were used as chiral ligands, a strong influence of their structure in the enantioselectivity or the addition of MeLi and n-BuLi to phenylimine 1a was observed. (C) 2001 Elsevier Science Ltd. All rights reserved.