Abstract
Heterogeneous organocatalysts hold great potential as they offer practical advantages in terms of purification and reusability compared with the homogeneous counterpart. A puzzling aspect is the solvent effect on their catalytic performance. Here we propose a new approach whereby T1/T2 NMR relaxation measurements are used to evaluate the strength of solvent–surface interactions in the polystyrene-supported N-heterocyclic carbene-promoted oxidation of aldehydes. The results reveal that solvents with high surface affinity lead to a decrease in catalyst activity.
Highlights
Heterogeneous organocatalysts hold great potential as they offer practical advantages in terms of purification and reusability compared with the homogeneous counterpart
In the toolkit of organic chemists, oxidative coupling of aldehydes is among the most desirable routes due to the high stability of the aldehyde group compared to the acyl halide and the better atom economy of the overall process.[3]
In 2015 Sundeń and co-workers[7] disclosed an efficient protocol to convert α,β-unsaturated aldehydes into the corresponding esters employing a triazolium salt (NHC) along with a mediator couple composed of an FePc (iron(II) phthalocyanine) and 2,6-di-tert-butylphenol
Summary
Heterogeneous organocatalysts hold great potential as they offer practical advantages in terms of purification and reusability compared with the homogeneous counterpart. Unlike reactions in the presence of homogeneous organocatalysts, reactions over solid heterogeneous organocatalysts can be significantly affected by diffusion and adsorption behavior of reaction species over the surface.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
