Asymmetric Sulfinylations of N‐Methylephedrine‐Modified Tri‐ or Tetraalkyl Zincates by Symmetric Diaryl Sulfoxides
Asymmetric Sulfinylations of N‐Methylephedrine‐Modified Tri‐ or Tetraalkyl Zincates by Symmetric Diaryl Sulfoxides
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DOI：
10.1002/ejoc.201701603
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发表时间：
2018-06
影响因子：
2.8
通讯作者：
Simon Ruppenthal;R. Brückner
中科院分区：
文献类型：
--
作者：
Simon Ruppenthal;R. Brückner
将二乙基锌用1或2当量的THF处理。的AlkMgCl或PhMgBr（优选）或与1当量的AlkMgCl或PhMgBr（优选）反应。ofnBuLi（效率较低）用于形成物种--可能是锌酸盐--其被二芳基亚砜亚磺酰化，得到外消旋烷基芳基亚砜，产率达到100%。二烷基锌试剂也通过用1或2当量的二烷基锌处理来活化。对映体纯的烷基镁β-氨基醇盐。当醇盐来源于二烷基镁试剂和等摩尔量的N-甲基-（-）-麻黄碱时，效果最好。这种第二种活化模式允许最初的二烷基锌试剂与二芳基亚砜的亚磺酰化。这产生了对映体比率高达93：7的烷基芳基亚砜，产率高达100%。
Diethylzinc was treated with 1 or 2 equiv. of AlkMgCl or PhMgBr (preferably) or with 1 equiv. ofnBuLi (less efficiently) for forming species – plausibly zincates – which were sulfinylated by diaryl sulfoxides to give racemic alkyl aryl sulfoxides in yields reaching 100 %. Dialkylzinc reagents were also activated by treatments with 1 or 2 equiv. of an enantiomerically pure alkylmagnesium β‐aminoalkoxide. This worked best when the alkoxide stemmed from a dialkylmagnesium reagent and an equimolar amount ofN‐methyl‐(–)‐ephedrine. This second activation mode allowed sulfinylations of what was originally the dialkylzinc reagent with diaryl sulfoxides. This generated alkyl aryl sulfoxides with enantiomeric ratios up to 93:7 in up to 100 % yield.