Mapping catalyst activation, turnover speciation and deactivation in Rh/PPh 3 -catalysed olefin hydroformylation
Mapping catalyst activation, turnover speciation and deactivation in Rh/PPh 3 -catalysed olefin hydroformylation
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绘制 Rh/PPh 3 催化烯烃加氢甲酰化中催化剂活化、周转形态和失活的图谱
DOI：
10.1039/d2cy00312k
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发表时间：
2022
影响因子：
5
通讯作者：
Bara-Estaún A
中科院分区：
文献类型：
--
作者：
Bara-Estaún A
我们报告新的见解，贵金属的命运在加氢催化1-己烯与Rh/PPh 3配合物使用多核操作FlowNMR光谱。通过应用选择性激发的1H和31 P {1H} NMR脉冲序列，我们能够对在周转期间形成的关键双铑和酰基铑中间体以及休眠的二聚羰基络合物进行定性和定量。以这种方式得到的定量催化剂分布图解释了在一系列反应条件下的催化剂稳定性和活性，包括为什么贫CO条件通过抑制二聚体和簇形成而产生更快的加氢催化。五种常用的前体的活化行为和膦-膦酰基络合物[RhH（CO）（PPh 3）3]的热稳定性进行了研究，并证明了应用受控温度梯度进行动态催化剂系统的定量FlowNMR光谱反应监测的好处。
We report new insights into the fate of the precious metal during hydroformylation catalysis of 1-hexene with Rh/PPh3 complexes using multi-nuclear operando FlowNMR spectroscopy. By applying selectively excited 1H and 31P{1H} NMR pulse sequences we were able to characterise and quantify key hydrido-rhodium and acyl-rhodium intermediates formed during turnover as well as dormant dimeric carbonyl complexes. The quantitative catalyst distribution maps derived this way explain catalyst stability and activity across a range of reaction conditions, including why CO-lean conditions give faster hydroformylation catalysis through the suppression of dimer and cluster formation. The activation behaviour of five commonly used precursors and the thermal stability of the phosphine-hydrido complex [RhH(CO)(PPh3)3] have been investigated, and the benefits of applying controlled temperature gradients for quantitative FlowNMR spectroscopic reaction monitoring of dynamic catalyst systems are demonstrated.