Asymmetric synthesis of β-lactams and pseudopeptides via stereoselective conjugate additions of lithium (α-methylbenzyl)allylamide to α,β-unsaturated iron acyl complexes
作者:Stephen G. Davies、Narciso M. Garrido、Paul A. McGee、John P. Shilvock
DOI:10.1039/a906633k
日期:——
undergoes stereoselective conjugate additions to α,β-unsaturated iron acyl complexes 3a–c to afford β-amino iron acyl adducts 5a–c and 6a–c. These adducts may be deallylated smoothly using palladium(0) catalysis providing the corresponding homochiral secondary amines 7a–c which, upon oxidative decomplexation with bromine or N-bromosuccinimide, undergo direct β-lactam ring formation. The diastereoselectivity
锂(α-甲基苄基)烯丙基酰胺2经过立体选择性共轭加成后的α,β-不饱和铁酰基复合物3a-c生成β-氨基铁酰基加成物5a-c和6a-c。这些加合物可以使用钯(0)催化平稳地脱醛,提供相应的同手性仲胺7a-c,与溴或N-溴代琥珀酰亚胺氧化分解后,会直接形成β-内酰胺环。通过使用酰胺镁10,可以进一步改善对缀合物加至3a的非对映选择性。在α-氨基酯存在下,β-氨基铁酰基加合物5b之一的氧化分解可提供包含α-氨基酸的假肽片段。与β-氨基酸偶联。