Abstract

Asymmetric desymmetrization was demonstrated by means of transition-metal-catalyzed conjugate reduction with hydrosilanes as reductants. Chiral rhodium-bis(oxazolinyl)phenyl complexes [Rh(Phebox-R)] were found to be effective catalysts for conjugate hydrosilylation of differently γ,γ-disubstituted cyclohexadienones to provide the corresponding product with chiral quaternary centers. The mechanistic consideration was also performed by theoretical calculation. These attempts provided information about i) the initial activation of Rh(III) complex into Rh(I) species assisted by hydrosilanes, ii) the complete catalytic cycle, and iii) an explanation of the asymmetric induction and the difference of the structure of cyclohexadienones in enantioselectivity.

Asymmetric desymmetrization was demonstrated by means of transition-metal-catalyzed conjugate reduction with hydrosilanes as reductants. Chiral rhodium-bis(oxazolinyl)phenyl complexes [Rh(Phebox-R)] were found to be effective catalysts for conjugate hydrosilylation of differently γ,γ-disubstituted cyclohexadienones to provide the corresponding product with chiral quaternary centers. The mechanistic consideration was also performed by theoretical calculation. These attempts provided information about i) the initial activation of Rh(III) complex into Rh(I) species assisted by hydrosilanes, ii) the complete catalytic cycle, and iii) an explanation of the asymmetric induction and the difference of the structure of cyclohexadienones in enantioselectivity.

中文翻译：

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铑催化的共轭氢化硅烷化对环己二酮的不对称脱对称及其机理的理论计算

摘要

通过过渡金属催化的共轭物还原反应证明了不对称脱对称，其中氢硅烷作为还原剂。发现手性铑-双（恶唑啉基）苯基络合物[Rh（Phebox-R）]是有效的催化剂，用于不同的γ，γ-二取代的环己二酮的共轭氢化硅烷化，从而为相应的产物提供手性季中心。力学考虑也通过理论计算进行。这些尝试提供了以下信息：i）由氢硅烷协助将Rh（III）配合物初步活化为Rh（I）物种，ii）完整的催化循环，以及iii）不对称诱导和环己二酮结构差异的解释对映选择性。

通过过渡金属催化的共轭物还原反应证明了不对称脱对称，其中氢硅烷作为还原剂。发现手性铑-双（恶唑啉基）苯基络合物[Rh（Phebox-R）]是有效的催化剂，用于不同的γ，γ-二取代的环己二酮的共轭氢化硅烷化，从而为相应的产物提供手性季中心。力学考虑也通过理论计算进行。这些尝试提供了以下信息：i）由氢硅烷协助将Rh（III）配合物初步活化为Rh（I）物种，ii）完整的催化循环，以及iii）不对称诱导和环己二酮结构差异的解释对映选择性。