Enantioselective One-Pot Conjugate Addition of Grignard Reagents to Cyclic Enones Followed by Amidomethylation
作者:Filip Bilčík、Michal Drusan、Jozef Marák、Radovan Šebesta
DOI:10.1021/jo202146f
日期:2012.1.6
Enantioselective conjugate addition of Grignard reagents to enones, catalyzed by Cu-Taniaphos or Josiphos complex, affords chiral enolates. Ensuing one-pot Mannich reaction with TiCl4-generated imine leads to aminocarbonyl compounds with benzyloxycarbonyl-protected nitrogen. Both diastereomers of these compounds are isolated in moderate yields but high enantiomeric purities (up to er 97.5:2.5).
Cu-Taniaphos或Josiphos配合物催化将格氏试剂对映体选择性对映体共轭加成,得到手性烯醇化物。随后与TiCl 4生成的亚胺进行一锅法曼尼希反应,得到带有苄氧羰基保护的氮的氨基羰基化合物。这些化合物的两种非对映异构体均以中等收率分离,但对映体纯度很高(高达er 97.5:2.5)。