Asymmetric Reduction of Oxime Ethers Promoted by Chiral Spiroborate Esters with an O3BN Framework
摘要:
Enatioselective reduction of oxime ethers promoted by chiral spiroborate esters with an O3BN framework is reported for the first time. In the presence of (R,S)-1, 11 aralkyloxime ethers are reduced by borane-THF at 0-5 degrees C to give (S)-1-aralkylamine in high yield and excellent enatiomeric excess (up to 98% ee). Influence of reaction conditions on the enantioselectivity of the reduction is investigated, and a possible mechanism of the catalytic reduction is suggested.
Asymmetric Synthesis of Primary Amines via the Spiroborate-Catalyzed Borane Reduction of Oxime Ethers
作者:Xiaogen Huang、Margarita Ortiz-Marciales、Kun Huang、Viatcheslav Stepanenko、Francisco G. Merced、Angel M. Ayala、Wildeliz Correa、Melvin De Jesús
DOI:10.1021/ol0704791
日期:2007.4.1
enantioselective borane reduction of O-benzyloxime ethers to primary amines was studied under catalytic conditions using the spiroborate esters 5-10 derived from nonracemic 1,2-amino alcohols and ethylene glycol. Effective catalytic conditions were achieved using only 10% of catalyst 5 derived from diphenylvalinol in dioxane at 0 degrees C resulting in complete conversion to the corresponding primary amine in
Asymmetric Reduction of Oxime Ethers Promoted by Chiral Spiroborate Esters with an O<sub>3</sub>BN Framework
作者:Yunbo Chu、Zixing Shan、Dejun Liu、Nannan Sun
DOI:10.1021/jo060123n
日期:2006.5.1
Enatioselective reduction of oxime ethers promoted by chiral spiroborate esters with an O3BN framework is reported for the first time. In the presence of (R,S)-1, 11 aralkyloxime ethers are reduced by borane-THF at 0-5 degrees C to give (S)-1-aralkylamine in high yield and excellent enatiomeric excess (up to 98% ee). Influence of reaction conditions on the enantioselectivity of the reduction is investigated, and a possible mechanism of the catalytic reduction is suggested.
efficient, reusable and stable binaphthyl stabilized Pd‐nanoparticles (Pd‐BNP) catalyzed the direct ortho‐C−H hydroxylation of acetophenone oxime ethers under neutral and phosphineligand‐free condition has been developed. A readily available, economic, safe and greener oxidant oxone has been used in this direct ortho‐hydroxylation. The scope of the reaction has been studied with various acetophenone oxime