Hydroamination Catalyzed by a Pd Catalyst Immobilized in a Thin Film

Significance

A palladium complex immobilized in a thin film of a silica-supported ionic liquid was developed which served as a bifunctional catalyst with soft Lewis acidic and strong Brønsted acidic functions. Thus, silica (aerosol 355, 150 m²/g; 5.0 g) was impregnated with a solution of Pd(CF₃CO₂)₂ (133 mg), DPPF (333 mg) and TfOH (150 mg; Pd²⁺/H⁺ = 10:1) in EMIm (2.5 mL) to give a free-flowing powder of the immobilized catalyst (Pd contents: 0.044 mmol Pd²⁺/g cat.). A bed reactor was filled with the catalyst (50 mg) and glass beads (remaining volume), and a solution of aniline with styrene in heptane passed through the reactor at 150-300 °C. The conversion attained a maximum of 35% at 240 °C.