The Core‐Shell Magnetic Mesoporous Microspheres Immobilized NHC‐Palladacycles: An Efficient and Recyclable Catalyst for Suzuki‐Miyaura Cross‐Coupling of Pharmaceutical Synthesis

Abstract The core‐shell magnetic mesoporous microspheres immobilized NHC‐palladacycles (NHC= N ‐heterocyclic carbene) catalyst with constrained aliphatic linker group (Fe 3 O 4 @mSiO 2 @NHC−Pd) were readily prepared by the well‐designed method, which showed higher palladium loading (0.20 mmol g −1 ) and catalytic activity than non‐mesoporous catalysts @SiO same process in Suzuki‐Miyaura cross‐coupling reactions of aryl chlorides boronic acids. Herein, Fe @NHC−Pd could be used 12 times without significant loss, no leakage was detected both product residue, highlighting efficiency our strategy for immobilizing catalyst. Remarkably, this approach allows synthesis important drug intermediates 2‐aryl‐4‐aminoquinazolines o ‐tolylbenzonitrile (OTBN).