significance and in great demand. Among these, C–H bondsilylation provides a powerful and straightforward synthetic method to form diverse silacycles in an atom- and step-economical fashion. However, C–H bondsilylation has not been used to access any six-membered silicon-bridged π-conjugated scaffolds and enantioselective six-membered C–H silylation has never been presented. Herein, we successfully
C / Si转换策略已被认为是发现药物和材料的有用和高效的策略。因此,开发访问各种硅杂环的方法学具有重要意义和需求。其中,C–H键甲硅烷基化提供了一种强大而直接的合成方法,可以以原子经济和分步经济的方式形成各种硅杂环。但是,尚未使用C–H键甲硅烷基化来获得任何六元硅桥π-共轭支架,并且从未提出对映选择性的六元C–H甲硅烷基化。在这里,我们通过C–H键甲硅烷基化成功地获得了多种多样的六元π共轭二苯并恶唑啉,并研究了它们的光物理性质。此外,我们认识到对映选择性六元C H硅烷化可以直接提供具有高ee(高达95%ee)的平面手性茂金属恶二唑烷。我们还证明了通过各种其他转化,二苯并恶唑啉和平面手性茂金属稠合的苯并恶唑啉作为有价值的合成中间体的合成有用性。此外,利用我们的方法设计并快速构建了六元硅桥梯π共轭体系。还详细评估了“异构化”和“硅”对分子几何形状和光物理性质的影响。利用我们的方法设计并快速构
Rhodium-Catalyzed Asymmetric Synthesis of Silicon-Stereogenic Dibenzooxasilines via Enantioselective Transmetalation
作者:Ryo Shintani、Eleanor E. Maciver、Fumiko Tamakuni、Tamio Hayashi
DOI:10.1021/ja3076555
日期:2012.10.17
A rhodium-catalyzed asymmetric synthesis of silicon-stereogenic dibenzooxasilines has been developed. High enantioselectivities have been achieved by employing (S,S)-Me-Duphos as the ligand through "enantioselective transmetalation".
TBDPS and Br-TBDPS Protecting Groups as Efficient Aryl Group Donors in Pd-Catalyzed Arylation of Phenols and Anilines
作者:Chunhui Huang、Vladimir Gevorgyan
DOI:10.1021/ja904791y
日期:2009.8.12
as an efficient phenyl group donor for o-bromophenols via Pd-catalyzed C-Harylation followed by a routine TBAF deprotection of the resulting silacycles. Employment of the newly designed Br-TBDPS protecting group in the same sequence allows for a facile introduction of a phenyl group at the ortho position of phenols and anilines. Alternatively, switching desilylation to oxidation in the last step allows