Asymmetric synthesis and applications of β-amino Weinreb amides: asymmetric synthesis of (S)-coniine
作者:Anthony J. Burke、Stephen G. Davies、A. Christopher Garner、Tom D. McCarthy、Paul M. Roberts、Andrew D. Smith、Humberto Rodriguez-Solla、Richard J. Vickers
DOI:10.1039/b402531h
日期:——
Conjugate addition of lithium (S)-N-benzyl-N-alpha-methylbenzylamide to a range of alpha, beta-unsaturated Weinreb amides proceeds with high levels of diastereoselectivity (>95% de). The beta-amino Weinreb amide products may be transformed into beta-amino ketones via reactions with Grignard reagents, while treatment with DIBAL-H furnishes beta-amino aldehydes. Trapping of the aldehyde via Wadsworth-Emmons
将锂(S)-N-苄基-N-α-甲基苄基酰胺共轭添加到一定范围的α,β-不饱和Weinreb酰胺中会产生高水平的非对映选择性(> 95%de)。通过与格氏试剂反应,可将β-氨基Weinreb酰胺产物转化为β-氨基酮,而用DIBAL-H处理可得到β-氨基醛。通过Wadsworth-Emmons反应和随后的操作捕集醛提供了一条制备高纯手性δ-氨基酸衍生物和2-取代的哌啶的有效途径。证明了该方法在合成(S)-甜菜碱中的应用。