Efficient synthesis of 2,3-dihydro-1H-pyrazoles via a highly selective Pd(0)-catalyzed coupling-cyclization reaction of terminal 2-substituted 2,3-allenyl hydrazines with aryl iodides
作者:Xin Cheng、Shengming Ma
DOI:10.1039/b903634b
日期:——
2,3-dihydro-1H-pyrazoles were highly selectively synthesized via the Pd(0)-catalyzed coupling-cyclization reaction of 4-non-substituted 2-substituted 2,3-allenyl hydrazines with aryl iodides in moderate to good yields.
An Efficient CuCN-Catalyzed Synthesis of Optically Active 2,3-Allenols from Optically Active 1-Substituted 4-Chloro-2-butyn-1-ols
作者:Jing Li、Wangqing Kong、Chunling Fu、Shengming Ma
DOI:10.1021/jo900710e
日期:2009.7.17
The sequential treatment of opticallyactive terminal propargylic alcohols with n-BuLi/(HCHO)n and regioselective chlorination afforded the corresponding opticallyactive 4-chloro-2-butyn-1-ols. With R1 being a methyl or an ethyl group, an alternative for the synthesis of the corresponding opticallyactive propargylic alcohols is the Novozym 435-catalyzed kinetic resolution of these racemic 4-chloro-2-butyn-1-ols
PdCl<sub>2</sub>/NaI-Catalyzed Homodimeric Coupling-Cyclization Reaction of 2,3-Allenols: An Efficient Synthesis of 4-(1‘,3‘-Dien-2‘-yl)-2,5-dihydrofuran Derivatives
作者:Youqian Deng、Yihua Yu、Shengming Ma
DOI:10.1021/jo702332m
日期:2008.1.1
A PdCl2/NaI-catalyzed homodimeric coupling-cyclizationreaction of 2,3-allenols was observed to provide an efficient route to 4-(1‘,3‘-dien-2‘-yl)-2,5-dihydrofuranderivatives. By using the easily available optically active starting materials, 2,5-dihydrofurans with high enantiopurity may be prepared. A Pd(II)-catalyzed mechanism was also discussed.