Understanding Rh‐catalysed Hydroformylation with Phosphite Ligands through Catalyst Speciation Analysis by <i>Operando</i> FlowNMR Spectroscopy
نویسندگان
چکیده
Phosphites are industrially important ligands for the Rh-catalysed hydroformylation of olefins because they produce more active catalysts than phosphines, which is mainly due to their strong π-acceptor properties facilitating CO dissociation from metal centre. Herein, effect three prominent phosphite (triphenylphosphite, Alkanox and BiPhePhos) on catalyst speciation during turnover investigated using multi-nuclear operando FlowNMR spectroscopy. The quantitative distribution maps derived explain activity trends across a range catalytic reaction conditions that show how phosphites catalysts, including reduced formation inactive Rh0 dimers in absence substrate pre-activation at end reaction. Additionally, [(alkanox)Rh(acac)] complexes have been found be high stability can exploited post-catalytic Rh recovery by simple addition 2,4-pentanediones.
منابع مشابه
Charged ligands for catalyst immobilisation and analysis.
Ligands involved in organometallic chemistry have been functionalised at locations somewhat removed from the binding site for diverse reasons, including modification of electronic and steric characteristics, improving solubility, to confer chirality, to add a spectroscopic "handle", to facilitate electron-transfer processes or for spin-labelling. Here, the focus is specifically on catalytically...
متن کاملContinuous Homogeneous Hydroformylation with Nanofiltration for Retention of Polymer Supported Rh Catalyst Complexes
Introduction Industrial higher olefin (> C5) hydroformylation processes require harsh temperatures and pressures (140 200 oC, 5 30 MPa) as well as tedious catalyst separation schemes involving hazardous reagents to recycle the cobalt catalyst [1]. The use of rhodium (Rh) as a catalyst would lower the operating temperature and pressure but requires almost quantitative recovery and recycle of the...
متن کاملRhodium/phospholane-phosphite catalysts give unusually high regioselectivity in the enantioselective hydroformylation of vinyl arenes.
Using the phospholane-phosphite ligand, BOBPHOS, almost perfect regioselectivities and high enantioselectivities (up to 92% ee) are observed in Rh catalysed enantioselective hydroformylation of vinyl arenes. This can be achieved under solvent-free conditions.
متن کاملPhosphite-oxazole/imidazole ligands in asymmetric intermolecular Heck reaction.
We describe the application of a new class of ligands--the phosphite-oxazole/imidazole (L1-L5a-g)--in asymmetric intermolecular Pd-catalyzed Heck reactions under thermal and microwave conditions. These ligands combine the advantages of the oxazole/imidazole moiety with those of the phosphite moiety: they are more stable than their oxazoline counterparts, less sensitive to air and other oxidizin...
متن کاملInsights into the Mechanism of Tandem Alkene Hydroformylation over a Nanostructured Catalyst with Multiple Interfaces.
The concept of tandem catalysis, where sequential reactions catalyzed by different interfaces in single nanostructure give desirable product selectively, has previously been applied effectively in the production of propanal from methanol (via carbon monoxide and hydrogen) and ethylene via tandem hydroformylation. However, the underlying mechanism leading to enhanced product selectivity has rema...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Chemcatchem
سال: 2023
ISSN: ['1867-3899', '1867-3880']
DOI: https://doi.org/10.1002/cctc.202201204