Synthetic Scope and Mechanistic Studies of Ru(OH)x/Al2O3-Catalyzed Heterogeneous Hydrogen-Transfer Reactions
作者:Kazuya Yamaguchi、Takeshi Koike、Miyuki Kotani、Mitsunori Matsushita、Satoshi Shinachi、Noritaka Mizuno
DOI:10.1002/chem.200500539
日期:2005.11.4
secondary alcohols, reduction of carbonyl compounds to alcohols using 2-propanol as a hydrogen donor, and isomerization of allylic alcohols to saturated ketones, are efficiently promoted by the easily prepared and inexpensive supported ruthenium catalyst Ru(OH)x/Al2O3. A wide variety of substrates, such as aromatic, aliphatic, and heterocyclic alcohols or carbonyl compounds, can be converted into the desired
易于制备且价格低廉的负载型钌有效地促进了三种氢转移反应,即手性仲醇的外消旋,使用2-丙醇作为氢供体的羰基化合物还原为醇,烯丙基醇异构化为饱和酮等。催化剂Ru(OH)x / Al2O3。在厌氧条件下,各种底物,例如芳族,脂肪族和杂环醇或羰基化合物,可以以中等至极好的收率转化成所需的产物,而无需添加添加剂,例如碱。还证明了更大规模的无溶剂反应:底物/催化剂比为20,000 / 1的1-辛烯-3-醇的异构化反应显示出18400 h(-1)的极高周转率(TOF),营业额(TON)达到17,200。这些反应的催化本质上本质上是多相的,反应后回收的Ru(OH)x / Al2O3可以重复使用而不会明显降低催化性能。用单氘化底物检查了本Ru(OH)x / Al2O3催化的氢转移反应的反应机理。在苯乙酮存在下,(S)-1-氘-1-苯基乙醇的外消旋作用完成后,相应消旋醇在α位的氘含量为91%,而在α位没有掺入