Understanding Rh-catalysed Hydroformylation with Phosphite Ligands through Catalyst Speciation Analysis by Operando FlowNMR Spectroscopy
Understanding Rh-catalysed Hydroformylation with Phosphite Ligands through Catalyst Speciation Analysis by Operando FlowNMR Spectroscopy
复制标题
通过 Operando FlowNMR 波谱法进行催化剂形态分析，了解亚磷酸酯配体的 Rh 催化加氢甲酰化反应
DOI：
10.1002/cctc.202201204
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发表时间：
2023
期刊：
影响因子：
4.5
通讯作者：
Bara-Estaún A
中科院分区：
文献类型：
--
作者：
Bara-Estaún A
亚磷酸酯是Rh催化烯烃加氢反应的重要工业配体，因为它们比膦产生更活性的催化剂，这主要是由于它们强的π受体性质促进CO从金属中心解离。在本文中，使用多核操作FlowNMR光谱研究了三种主要的亚磷酸酯配体（亚磷酸三苯酯，Alkanox和BiPhePhos）对周转期间催化剂形态的影响。所得到的定量催化剂分布图解释了在一系列催化反应条件下的活性趋势，这些催化反应条件显示了亚磷酸酯如何产生更活性的催化剂，包括在预活化期间和反应结束时在不存在底物的情况下减少非活性Rh 0二聚体的形成。此外，已发现[（alkanox）Rh（acac）]络合物具有高稳定性，其可通过简单添加2，4-戊二酮而用于后催化Rh回收。
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 the metal centre. Herein, the effect of three prominent phosphite ligands (triphenylphosphite, Alkanox and BiPhePhos) on catalyst speciation during turnover is investigated using multi‐nuclearoperandoFlowNMR spectroscopy. The quantitative catalyst distribution maps derived explain activity trends across a range of catalytic reaction conditions that show how phosphites produce more active catalysts, including reduced formation of inactive Rh0dimers in the absence of substrate during pre‐activation and at the end of the reaction. Additionally, [(alkanox)Rh(acac)] complexes have been found to be of high stability which can be exploited for post‐catalytic Rh recovery by simple addition of 2,4‐pentanediones.