Efficient and Chemoselective Reduction of Pyridines to Tetrahydropyridines and Piperidines via Rhodium-Catalyzed Transfer Hydrogenation
Efficient and Chemoselective Reduction of Pyridines to Tetrahydropyridines and Piperidines via Rhodium-Catalyzed Transfer Hydrogenation
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DOI：
10.1002/adsc.201201034
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发表时间：
2013-01-01
影响因子：
5.4
通讯作者：
Xiao, Jianliang
中科院分区：
文献类型：
--
作者：
Wu, Jianjun;Tang, Weijun;Xiao, Jianliang
在碘阴离子的促进下，铑络合物二聚体 [Cp*RhCl2]2 在温和条件下有效催化各种季吡啶盐的转移氢化，不仅提供哌啶，而且以高度化学选择性的方式提供 1,2,3,6-四氢吡啶，具体取决于吡啶环上的取代模式。还原反应在甲酸/三乙胺 (HCOOH-Et3N) 混合物中于 40℃ 下进行，催化剂负载量低至 0.005 mol% 是可行的。
Promoted by iodide anion the rhodium complex dimer, [Cp*RhCl2]2, catalyzes efficiently the transfer hydrogenation of various quaternary pyridinium salts under mild conditions, affording not only piperidines but also 1,2,3,6-tetrahydropyridines in a highly chemoselective fashion, depending on the substitution pattern at the pyridinium ring. The reduction is conducted in azeotropic formic acid/triethylamine (HCOOH-Et3N) mixture at 40?degrees C, with catalyst loadings as low as 0.005 mol% being feasible.