Stereodivergent Construction of Vicinal Acyclic Quaternary-Tertiary Carbon Stereocenters by Michael-Type Alkylation of α,α-Disubstituted N-tert-Butanesulfinyl Ketimines.
Stereodivergent Construction of Vicinal Acyclic Quaternary-Tertiary Carbon Stereocenters by Michael-Type Alkylation of α,α-Disubstituted N-tert-Butanesulfinyl Ketimines.
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DOI：
10.1021/acs.orglett.1c02660
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发表时间：
2021-09
期刊：
影响因子：
5.2
通讯作者：
Nuermaimaiti Yisimayili;H. Liu;Yun Yao;Chong-Dao Lu
中科院分区：
文献类型：
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作者：
Nuermaimaiti Yisimayili;H. Liu;Yun Yao;Chong-Dao Lu
通过对映体富集的带有两个空间相似的α-直链烷基取代基的无环N-叔丁烷亚磺酰基酮亚胺的氮杂烯醇化，然后与硝基烯烃共轭加成，以优异的立体选择性构建了邻位的季-叔碳立体中心。进一步改变酮亚胺中亚磺酰基和/或α-立构中心的绝对构型，可以容易地立体分散合成Michael型烷基化加合物的所有四种非对映异构体。该反应是基于立体选择性α-去质子化的无环立体控制的成功例子，用于从酮衍生物形成完全取代的氮杂烯醇化物。
Vicinal quaternary-tertiary carbon stereocenters were constructed with excellent stereoselectivity via aza-enolization of enantioenriched acyclic N-tert-butanesulfinyl ketimines bearing two sterically similar α-linear alkyl substituents followed by conjugate addition to nitroalkenes. Further changes of the absolute configuration of the sulfinyl group and/or the α-stereocenter in the ketimine allowed the facile stereodivergent synthesis of all four diastereomers of the Michael-type alkylation adducts. This reaction is a successful example of acyclic stereocontrol based on stereoselective α-deprotonation for the formation of fully substituted aza-enolates from ketone derivatives.