Selective Synthesis of Unsaturated Alcohols over Heterogeneous Metal-Ion Catalysts

以十六烷基三甲基溴化铵为模板剂合成了介孔硅酸盐MCM-41。将MCM-41、SiO_2、Al_2O_3、TiO_2和部分沸石浸渍在不同种类的锡和锆盐中。催化剂在规定的温度下煅烧还原。在不锈钢高压灭菌器（30ml）中用二次醇选择性还原巴豆醛和苯乙酮。巴豆醛在金属催化剂上加氢生成大量的丁醛和1-丁醇，对应C=C双键的氢化物。锡的加入能有效提高羰基氢化丁醇对金属催化剂的选择性。负载的Sn和Zr催化剂表明，加入的仲醇作为溶剂，通过氢转移反应选择性地还原羰基（MPV还原）。考察了载体盐和启动盐的影响。含MCM-41的二氧化硅适合作为Sn和Zr的载体。酸性或碱性支持无效。活性炭负载的锆也具有较高的活性。支座应选用中性多孔材料。还原温度对不饱和醇产率的影响表明，Sn （II）和Zr （IV）是选择性还原羰基化合物的活性物质。在合成混合物中加入辛可啶可改善s -1-苯基乙醇的对映异构体过量。

Mesoporous silicate, MCM-41 was synthesized by using hexadecyl trimethyl ammonium bromide as a template. MCM-41, SiO_2, Al_2O_3, TiO_2 and some zeolites were impregnated with some kinds of tin and zirconium salts. The catalyst were calcined and reduced at prescribed temperatures.The selective reductions of crotonaldehyde and acctophenone were carried out with a secondary alcohol in stainless steel autoclave (30 ml).Hydrogenation of crotonaldehyde over metallic catalysts produces significant amount of butyraldehyde and 1-butanol, corresponding hydrogenates of C=C doublc bond. The addition of Sn was effective to improve the selectivity of crotyl alcohol, corresponding hydrogenate of carbonyl group over metallic catalysts. The supported Sn and Zr catalysts indicated that carbonyl groups were selectivcly reduced via hydrogen transfer reaction from secondary alcohol added as a solvent (MPV reduction). The effects of support and starting salts were investigated. Silica including MCM-41 was suitable for the support of Sn and Zr. Acidic or basic support was not effective. Zirconium supported on active carbon was also highly active. Neutral porous materials should be selected for the supports. Tin acetate for Sn catalysts and zirconium oxychloride for Zr catalysts were ones of the best starting salts, respectively Dependence of reduction temperature on the yicld of unsaturated alcohol indicated that Sn (II) and Zr (IV) were active species for the selective reduction of carbonyl compounds. Enatiomeric-excess of S-1-phenyl ethanol was improved by the addition of cinconidine in the reation mixture.