Stereoselective synthesis of optically active 2-alkylpiperidines utilizing electrochemical oxidation as a key step
- 作者：Osamu Onomura ; Yasuhisa Kanda ; Mieko Imai and Yoshihiro Matsumura
- 关键词：Optically active 2-alkylpiperidines ; 2-Methoxy-3 ; 4-didehydropiperidines ; Electrochemical oxidation ; Catalytic asymmetric reaction ; Copper ion-catalyzed
- 刊名：Electrochimica Acta
- 出版年：2005
- 期刊代码：30_00134686
- 类别：ch
- 出版时间：2005
- 卷：50
- 期：25-26
- 页码：4926-4935
- 文件大小：338 K
摘要
Efficient asymmetric carbon–carbon bond-forming reaction at the 2-position of a piperidine skeleton was achieved through scrutinizing chiral catalysts, copper ions, nucleophiles, and reaction temperatures. The key intermediates in this method were 2-methoxy-3,4-didehydropiperidines, which were easily prepared by electrochemical oxidation of 1-protected piperidines in methanol followed by didehydrogenation of the oxidation products. This method involved a chiral Cu(II) catalyzed coupling reaction between 1-(4-methoxybenzoyl)-3,4-didehydro-2-methoxypiperidine and nucleophiles such as dimethyl malonate and methyl acetoacetate to afford 2-substituted piperidines with up to 82%e.e. (e.e., enantiomeric excess).