Highly efficient Suzuki cross-coupling reaction within an open channel plastic microreactor immobilized with palladium complexes

A practical open channel microfluidic reactor with immobilized palladium complex was built on a cyclic olefin copolymer (COC) chip that was fabricated with a very simple hot-embossing technique. Palladium complex was immobilized on a photochemically grafted layer of polymerized N-[3-(dimethylamino)propyl]methacrylamide. Surface modification and catalyst immobilization onto COC were systematically characterized with streaming potential, surface contact angle, attenuated total reflection Fourier transform infrared spectrometry, scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. The reactor was comprised of a single 15 cm long serpentine channel of 120 μm (i.d.) and exhibited high efficiency for the Suzuki cross-coupling reaction of aryl iodides and bromides with arylboronic acids, affording good to excellent yields of the corresponding products. The reactions could be carried out smoothly with reduced reaction time and lower reactant consumption in the microreactor thermostated at 50°C. The proposed system may have great potential for high-throughput screening of catalysts and reaction conditions.