Development of Selective Alkene Hydrogenation with Atomic Hydrogen Permeating through a Pd Sheet Electrode for Industrialization

在有机合成中，烯烃的加氢是非常重要的，但在相同的条件下，烯丙基C-O键和苯氧基(Bn-O-)的氢解也会发生。因此，含烯丙氧基和/或苄氧基的烯烃很难在没有氢解的情况下被活性氢加氢。一种新的利用电化学产生的活化氢的加氢体系已成功地应用于几种不饱和有机化合物(如苯乙烯及其衍生物)的饱和。反应池由两个隔室组成，由Pd板作为阴极，在Pd板的一侧进行恒流电解水产生活性氢，通过Pd板渗入的活性氢在相反的侧面加氢衬底。

Hydrogenation of an alkene is quite important for organic' syntheses employing a catalyst (Pd, Ni, Pt) which chemisorbes active hydrogen, however, hydrogenolysis of allylic C-O bonds and benzyloxy groups (Bn-O-) also takes place under the same conditions. Therefore, it is difficult for alkenes having an allyloxy and/or benzyloxy group to be hydrogenated by active hydrogen without the hydrogenolysis.A new hydrogenation system utilizing electrochemically produced activehydrogen has been successful in the saturation of several unsaturated organic compounds such as styrene and its derivates.The reaction cell is made up of two compartments separated by a Pd sheet as cathode, where galvanostatic electrolysis of water is carried out to produce the active hydrogen atone side of the Pd sheet, and a substrate is hydrogenated at the opposite side surface by active hydrogen permeating through the Pd sheet.