Pd Catalyst Supported Thermo-Responsive Modified Poly(N-isopropylacrylamide) Grafted Fe۳O۴@CQD@Si in Heck Coupling Reaction

A new smart Pd catalyst was created based on functionalized thermo-responsive poly (N-isopropylacrylamide) (PNIPAM) grafted Fe۳O۴@CQD@Si. For catalyst fabrication, initially, Fe۳O۴ magnetic nanoparticle was prepared by co-precipitation method, and then it was coated with CQD as sustainable and environmentally friendly support. Chemical modification of Fe۳O۴@CQD support with polymerizable groups was performed through vinyltriethylsilan (VTES) reaction. Thereafter, PNIPAM was grafted to the modified Fe۳O۴ via the conventional free radical polymerization technique. The PNIPAM-grafted Fe۳O۴@CQD@Si was further treated using hydrazine to create the modified amino support, which was then complexed with Pd(OAc)۲ to yield the magnetic heterogeneous catalytic system. All materials are characterized using various methods, i.e., FT-IR, SEM, DLS, CHN, XRD, zeta potential, VSM, and TGA analysis techniques. Fe۳O۴@CQD@Si@PNIPAM-NH۲/Pd catalyst was used to produce a range of substituted alkenes in the Mizoroki-Heck cross-coupling reaction with a high turnover number (TON) and good to outstanding yields. Above the LCST temperature of the PNIPAM, the hydrophobic part of the polymer starts to shrink, and this smart catalyst advances the relevant reactions in milder conditions. Easy purification of the substituted alkenes due to the convenient isolation of the magnetic catalyst with an external magnet is the main characteristic of this process.

Keywords:

thermo , responsive polymers PNIPAM Pd catalyst Mizoroki , Heck coupling