*2.4.2 Functionalized magnetic nanoparticles*

Gamma (γ) Fe2O3 MNPs immobilized with Pd-DABCO (*1,4-diazabicyclo[2.2.2] octane*) complex were prepared where the nitrogen atoms coordinates with

**Figure 3.** *Pd supported on MNPs—Suzuki coupling [16].*

**Figure 4.** *Pd-DABCO supported on magnetic nanoparticles, Mizoroki-Heck reaction [17].*

Palladium, forming complex (**Figure 4**). Chloro-functionalized γ-Fe2O3 was prepared by reacting Fe2O3 with chloropropyltrimethoxysilane. Treatment with DABCO gave the DABCO-γ-Fe2O3. Further reaction with Pd(OAc)2 gave the desired Pd-DABCO-γ-Fe2O3. This catalyst was proven to be a recyclable catalyst for Hecktype coupling reactions.

Heck reactions were carried out with aryl iodobenzene to give high yields of the products in 30 min. Aryl bromide and chlorides also underwent the Heck-type coupling reactions but requiring longer reaction times of 12–24 h. The average isolated yield of 90% was retained for five consecutive runs [17]. An external magnet was used to separate the catalyst from the reaction mixture and reused at least five times without significant degradation in its catalytic activity. The pictorial representation of the catalytic preparation and the reaction is depicted in **Figure 4**.
