One‐Pot Multistep Cascade Reactions over Multifunctional Nanocomposites with Pd Nanoparticles Supported on Amine‐Modified Mesoporous Silica

Two kinds of multifunctional nanocomposites, SBA-15-NH2/Pd-p and SBA-15-NH2/Pd-f, with platelet-like and fiber-like morphologies, respectively, were fabricated by immobilizing Pd NPs onto amine-functionalized SBA-15. Some of the amino groups acted as anchoring sites for Pd NPs, whilst the remaining groups acted as Brønsted basic sites. As a result, the composites served as excellent multifunctional heterogeneous catalysts for one-pot multistep cascade reaction sequences. Moreover, when diffusion was the rate-determine step, SBA-15-NH2/Pd-p, with small mesopores, was superior to the fiber-like control sample, owing to its short diffusion length, a lower possibility of pore clogging, and better mass transportation for the reaction species during the catalysis.