An Efficient Nickel Catalyst for the Reduction of Carbon Dioxide with a Borane
摘要:
Nickel hydride with a diphosphinite-based ligand catalyzes the highly efficient reduction of CO(2) with catecholborane, and the hydrolysis of the resulting methoxyboryl species produces CH(3)OH in good yield. The mechanism involves a nickel formate, formaldehyde, and a nickel methoxide as different reduced stages for CO(2). The reaction may also be catalyzed by an air-stable nickel formate.
Trapping Formaldehyde in the Homogeneous Catalytic Reduction of Carbon Dioxide
作者:Sébastien Bontemps、Sylviane Sabo-Etienne
DOI:10.1002/anie.201304025
日期:2013.9.23
Formaldehyde detectives: Evidence for the production of formaldehyde during a ruthenium‐catalyzed CO2 reduction process, and for its involvement in the formation of the resulting C2 compound, is disclosed. Ultimately, formaldehyde can be recovered by methanol trapping. HBPin=pinacolborane.
One and two: The C2compound pinBOCH2OCHO (see scheme; HBpin=pinacolborane) and several C1compounds have been obtained from the borane‐mediated reduction of CO2 under mild conditions with the catalyst precursor [RuH2(H2)2(PCy3)2]. Mechanistic investigation highlights the role of a series of new carbonyl ruthenium complexes that were characterized by multinuclear NMR spectroscopy, IR spectroscopy,
molecule, remains an elementary C1 building block to be observed. Herein we report the direct observation of free formaldehyde from the borane reduction of CO2 catalyzed by a polyhydride ruthenium complex. Guided by mechanistic studies, we disclose the selective trapping of formaldehyde by in situ condensation with a primary amine into the corresponding imine in very mild conditions. Subsequent hydrolysis