- Rhodium-Catalyzed 2-Arylphenol-Derived Six-Membered Silacyclization: Straightforward Access toward Dibenzooxasilines and Silicon-Containing Planar Chiral Metallocenes
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The C/Si switch strategy has been regarded as a useful and efficient strategy for the discovery of drugs and materials. Thus, development of a methodology to access diverse silacycles is of great significance and in great demand. Among these, C-H bond silylation provides a powerful and straightforward synthetic method to form diverse silacycles in an atom- and step-economical fashion. However, C-H bond silylation 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 accessed diverse six-membered π-conjugated dibenzooxasilines via C-H bond silylation and investigated their photophysical properties. Furthermore, we realized enantioselective six-membered C-H siylation to directly afford planar chiral metallocene oxasilolanes with high ee (up to 95% ee). We also demonstrated the synthetic usefulness of dibenzooxasilines and planar chiral metallocene-fused benzooxasilolines as valuable synthetic intermediates via diverse additional transformations. Moreover, six-membered silicon-bridged ladder π-conjugated systems were designed and rapidly constructed by using our methods. The isomerization and silicon effects on molecular geometries and photophysical properties were also evaluated in detail.
- Zhao, Wen-Tao,Lu, Zhuo-Qun,Zheng, Hanliang,Xue, Xiao-Song,Zhao, Dongbing
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- Rhodium-catalyzed asymmetric synthesis of silicon-stereogenic dibenzooxasilines via enantioselective transmetalation
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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".
- Shintani, Ryo,MacIver, Eleanor E.,Tamakuni, Fumiko,Hayashi, Tamio
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p. 16955 - 16958,4
(2012/12/13)
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- Rhodium-catalyzed asymmetric synthesis of silicon-stereogenic dibenzooxasilines via enantioselective transmetalation
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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".
- Shintani, Ryo,MacIver, Eleanor E.,Tamakuni, Fumiko,Hayashi, Tamio
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p. 16955 - 16958
(2013/01/15)
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- TBDPS and Br-TBDPS protecting groups as efficient aryl group donors in Pd-catalyzed arylation of phenols and anilines
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(Chemical Equation Presented) It is shown that the TBDPS protecting group can serve as an efficient phenyl group donor for o-bromophenols via Pd-catalyzed C-H arylation 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 the conversion of forming silacycles into valuable o-biphenols.
- Huang, Chunhui,Gevorgyan, Vladimir
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supporting information; experimental part
p. 10844 - 10845
(2009/12/04)
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