Enantiospecific Synthesis of N-(9-Phenylfluoren-9-yl)-α-amino Ketones
摘要:
Enantiomerically pure N-(9-phenylfluoren-9-yl)-alpha-amino ketones were prepared in excellent yields by acylation of organolithium reagents with N-(9-phenylfluoren-9-yl)-alpha-amino acid-derived oxazolidinones. The method is not applicable for the acylation of Grignard reagents as they attack the methylenic carbon of the oxazolidinone to give the corresponding N-alkylated amino acids 13 in excellent yields. The resulting N-(9-phenylfluoren-9-yl)-alpha-amino ketones 8 could be stereoselectively reduced to the corresponding syn- or anti-beta-amino alcohols depending upon the nature of the reducing agent.
Enantioselective Addition of Diethylzinc to Aldehydes Catalyzed by <i>N</i>-(9-Phenylfluoren-9-yl) β-Amino Alcohols
作者:M. Rita Paleo、Isabel Cabeza、F. Javier Sardina
DOI:10.1021/jo9917083
日期:2000.4.1
A set of secondary N-phenylfluorenyl beta-amino alcohols have been prepared and evaluated as catalysts for the enantioselectiveaddition of diethylzinc to benzaldehyde. The influence of the substituents on the stereogenic centers of the ligand has been studied, and enantioselectivities up to 97% have been obtained. Those ligands with bulky groups in the carbinol stereocenter and small groups alpha
Enantiospecific Synthesis of <i>N</i>-(9-Phenylfluoren-9-yl)-α-amino Ketones
作者:M. Rita Paleo、M. Isabel Calaza、F. Javier Sardina
DOI:10.1021/jo9707646
日期:1997.10.1
Enantiomerically pure N-(9-phenylfluoren-9-yl)-alpha-amino ketones were prepared in excellent yields by acylation of organolithium reagents with N-(9-phenylfluoren-9-yl)-alpha-amino acid-derived oxazolidinones. The method is not applicable for the acylation of Grignard reagents as they attack the methylenic carbon of the oxazolidinone to give the corresponding N-alkylated amino acids 13 in excellent yields. The resulting N-(9-phenylfluoren-9-yl)-alpha-amino ketones 8 could be stereoselectively reduced to the corresponding syn- or anti-beta-amino alcohols depending upon the nature of the reducing agent.