Temperature-Tunable and Effector-On-Demand Dual Polymer Organocatalyst by Controllable Lower Critical Solution Temperature and Upper Critical Solution Temperature Thermoresponsive Polymer

The control of catalytic activity using thermoresponsive polymers has garnered continuous interest for applications of stimuli-responsive polymers. This report introduces a polymer catalyst featuring a DMAP (4-(dimethylamino)pyridine) moiety as an organocatalyst and a pyrenylmethyl group as a donor for a charge transfer complex to solvate the polymer chain. In the presence of the acceptor, N,N′-bis(2-ethylhexyl)pyromellitic diimide (PDI) or 7,7′,7″-(nitrilotris(ethane-2,1-diyl))tris(2-(2-octyldodecyl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone) (TNDI), as solvating reagents called effectors, enhanced the catalytic activity for the acylation by an acid anhydride due to solubilization of the polymer catalyst. Moreover, PDI or TNDI induced lower critical solution temperature (LCST)-type or upper critical solution temperature (UCST)-type phase transitions in 1,2-dimethoxyethane, respectively. The addition of the effector decreased or increased the catalytic activity by changing the temperature around the cloud point due to the coil–globule transition. These findings demonstrate that thermal control of the catalytic activity can be achieved through the control of the polymer solvation by effector alteration, offering a unique stimuli-responsive polymer catalyst in organic media.