High Stereocontrol in the Preparation of Silyl-Protected γ-Substituted Enoldiazoacetates
High Stereocontrol in the Preparation of Silyl-Protected γ-Substituted Enoldiazoacetates
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DOI：
10.1055/s-0037-1611865
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发表时间：
2019-07-01
期刊：
影响因子：
2
通讯作者：
Doyle, Michael P.
中科院分区：
文献类型：
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作者：
Dong, Kuiyong;Marichev, Kostiantyn O.;Doyle, Michael P.
报道了以双（三甲基硅基）氮烷锂（LiHMDS）为碱，TIPSOTf为硅转移试剂，合成了一系列三异丙基硅基（TIPS）保护的γ-取代烯醇重氮乙酸酯。尽管与先前的叔丁基二甲基甲硅烷基（TBS）保护的相比，它们的尺寸增加。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，实现了高的产物收率和优异的立体控制。
A robust and efficient synthesis of triisopropylsilyl (TIPS)protected gamma-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. unsubstituted enoldiazoacetates, a high product yield with exceptional stereocontrol has been achieved in copper-catalyzed [3+3] cycloaddition reaction with nitrones by using a chiral indeno bisoxazoline ligand.