Assessing Dual Rh/Ru Cascade Catalysts in One-Pot Homogeneous Synthesis of Ethanol from Syngas and Methanol

The direct conversion of cheap syngas into value-added ethanol at an industrial scale is in high demand.Herein we disclose a one-pot homogeneous homologation of methanol to ethanol with syngas via a rhodium/ruthenium bimetallic catalytic approach.By introducing a catalytic amount of methyl iodide,methanol can be converted to ethanol with high selectivity(>91%ethanol).A syngas ratio of H_(2)/CO=4:1 was found to be optimal.Among various phosphine ligands tested,Rh-dppp catalyst gave the highest aldehyde pathway selectivity,thus providing an effective route for the synthesis of ethanol upon coupling with a Ru hydrogenation catalyst.The bite angle of the bisphosphine ligands dramatically influences the selectivity of the dual Rh/Ru metallic cascade catalysts.In line with the experimental findings,theoretical calculations predicted a rational trend of the selectivity of different bisphosphine ligands via varying bite angle properties.

二茂铁骨架系列三齿配体的合成及其在铱催化不对称氢化中的应用

本文主要介绍了一系列基于二茂铁骨架的三齿配体:f-amphox、f-ampha、f-amphol和f-amphamide的合成及其应用。这四类手性膦氮配体的铱络合物可以高活性(TON高达1000000)、高转化率(>99%)、高对映选择性(>99%ee)地催化(官能团化)酮等底物的不对称氢化反应。该系列配体成功地应用于地诺帕明、苯福林和沙丁胺醇等手性医药中间体的不对称合成。与传统路线相比,这些合成方法更高效,副产物更少,"三废"排放量更低。