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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Monoamine on April 08, 2021, 08:51:14 PM

Title: Catalyst "supported on polystyrene"
Post by: Monoamine on April 08, 2021, 08:51:14 PM
I was reading a synthesis recently, and the authors stated that they used something called PS-BEMP as a catalyst in one of the reaction steps. According to them, this is 2-tert-butylimino-2-
diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine supported on polystyrene , which they claim is a very strong base.
I understand the "using a base as a catalyst" part, but I don't know what "supported on polystyrene" means?

Is the above chemical somehow attached to pieces of polystyrene, which are then placed into the reaction vessel? And if so, how is this usually done? (I'm pretty sure they don't mean take a piece of polystyrene, lather it in super glue and then dip it in the base...)

FYI: I saw this in the following paper about Henry syntheses:
Angelini T, Ballerini E, Bonollo S, Curini M, Lanari D. A new sustainable protocol for the synthesis of nitroaldol derivatives via Henry reaction under solvent-free conditions. Green Chemistry Letters and Reviews. 2014 Jan 2;7(1):11-7

Title: Re: Catalyst "supported on polystyrene"
Post by: Corribus on April 09, 2021, 12:20:57 PM
The catalyst is covalently attached to a polymer backbone. This allows the catalyst to be easily recoverable after the reaction by isolation of the polymer.

See, e.g., https://pubs.acs.org/doi/10.1021/cr8004444

Have you heard of solid-phase peptide synthesis? Same concept.