High Stereocontrol in the Preparation of Silyl-Protected γ-Substituted Enoldiazoacetates
作者:Kuiyong Dong、Kostiantyn O. Marichev、Xingfang Xu、Michael P. Doyle
DOI:10.1055/s-0037-1611865
日期:2019.7
A robust and efficient synthesis of triisopropylsilyl (TIPS)-protected γ-substituted enoldiazoacetates with excellent Z stereocontrol by using lithium bis(trimethylsilyl)azanide (LiHMDS) as a base and TIPSOTf as a silyl transfer reagent is reported. Despite their increased size compared to previously tert-butyldimethylsilyl (TBS)-protected γ-unsubstituted enoldiazoacetates, a high product yield with
报道了使用双(三甲基甲硅烷基)氮杂锂(LiHMDS)作为碱和 TIPSOTf 作为甲硅烷基转移试剂,稳健有效地合成三异丙基甲硅烷基(TIPS)保护的 γ-取代烯醇重氮乙酸酯,并具有优异的 Z 立体控制。尽管与之前的叔丁基二甲基甲硅烷基 (TBS) 保护的 γ-未取代烯醇重氮乙酸酯相比,它们的尺寸有所增加,但在铜催化的 [3+3] 环加成反应中,通过使用手性茚并双恶唑啉配体与硝酮反应,实现了高产率和出色的立体控制.