Iron-Catalyzed Unexpected Easy Access to Stereodefined Trimethylsilyl Vinyl Ketenes
作者:Guobi Chai、Chunling Fu、Shengming Ma
DOI:10.1021/ol3016176
日期:2012.8.17
Stereodefined trimethylsilyl vinyl ketenes with polysubstitution have been synthesized highly regio- and stereoselectively via an iron-catalyzed reaction of 2-trimethylsilyl-2,3-allenoates with Grignardreagents in good to excellent yields. The reaction was believed to proceed via a conjugate addition and elimination mechanism. Applications of the products for the synthesis of stereodefined α-silyl-β
Stereospecific anti SE2′ fluorination of allenylsilanes: synthesis of enantioenriched propargylic fluorides
作者:Laurence Carroll、Samantha McCullough、Tom Rees、Timothy D. W. Claridge、Véronique Gouverneur
DOI:10.1039/b803888k
日期:——
The electrophilic fluorodesilylation of enantioenriched allenylsilanes proceeds with efficient transfer of chirality. The silylationâfluorination of propargylic alcohols occurs with overall retention of stereochemistry, a result consistent with a stereospecific anti SE2â² mechanism for the fluorination step.