Direct and Stereospecific Synthesis of Allenes via Reduction of Propargylic Alcohols with Cp<sub>2</sub>Zr(H)Cl
作者:Xiaotao Pu、Joseph M. Ready
DOI:10.1021/ja8035527
日期:2008.8.1
Allenes can be synthesized via the direct SN2' addition of hydride to propargylicalcohols. Previous examples of this approach, however, have involved harsh reaction conditions and have suffered from incomplete transfer of central chirality to axial chirality. Here we show that Cp2Zr(H)Cl can react with the zinc or magnesium alkoxides of propargylicalcohols to generate allenes in good yield and in
Iron-Catalyzed Carbometalation of Propargylic and Homopropargylic Alcohols
作者:Donghui Zhang、Joseph M. Ready
DOI:10.1021/ja0647708
日期:2006.11.1
regioselectivity of addition. Here we demonstrate that Fe(III) salts are effective precatalysts for the carbometalation of alkynes. Primary and secondary propargylic and homopropargylic alcohols react with alkyl and aryl Grignard reagents to provide Z-allylic and -homoallylic alcohols as single stereo and regioisomers. Alkylation and arylation occur distal to the alcohol. Common oxygen protecting groups and tertiary