Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.
J Am Chem Soc. 2011 Jun 29;133(25):9666-9. doi: 10.1021/ja202732q. Epub 2011 Jun 6.
The transition state for the metal-ligand bifunctional addition step in Noyori's enantioselective ketone hydrogenation was investigated using intramolecular trapping experiments. The bifunctional addition between the Ru dihydride trans-[Ru((R)-BINAP)(H)(2)((R,R)-dpen)] and the hydroxy ketone 4-HOCH(2)C(6)H(4)(CO)CH(3) at -80 °C exclusively formed the corresponding secondary ruthenium alkoxide trans-[Ru((R)-BINAP)(H)(4-HOCH(2)C(6)H(4)CH(CH(3))O)((R,R)-dpen)]. Combined with the results of control experiments, this observation provides strong evidence for the formation of a partial Ru-O bond in the transition state.
使用分子内捕获实验研究了 Noyori 对映选择性酮加氢反应中金属-配体双功能加成步骤的过渡态。在-80°C 下，Ru 二氢化物反式-[Ru((R)-BINAP)(H)(2)((R,R)-dpen)]与羟基酮 4-HOCH(2)C(6)H(4)(CO)CH(3)之间的双功能加成仅形成相应的仲钌烷氧基反式-[Ru((R)-BINAP)(H)(4-HOCH(2)C(6)H(4)CH(CH(3))O)((R,R)-dpen)]。结合控制实验的结果，这一观察结果为过渡态中形成部分 Ru-O 键提供了有力证据。
