Several Applications Of Microfluidic Chip Reactor In Organic Synthesis

Researches on microfluidic chips are always the hotspot in micro analytical chemistry. With the development of microreactor, microfluidic chip has been widely used in organic synthesis, due to its attractive features. Fast mass/heat transfer, perfect mix, easy parameter-control and high selectivity in microchannel help it achieve fast screening in microscale. Less starting material, high screening efficiency makes a reaction "greener". Our researches focused on some organic reactions performed in microfluidic chip, which are quickly optimized and showed excellent selectivity and yield. Main contents and results are listed below:1. A Fridel-Crafts acylation reaction was reported. After screenings of reaction temperature, velocity of injection and concentrations of substrates, optimized condition was decided. Then, the influence of flow in microchanel on yield was discussed according experimental data. The microreaction proceeded very fast and is easy to handle. Monoacylation products were obtained in high selectivity and yields.2. On the basis of published work in our lab, a three-component one-pot reaction of o-phenylenediamine, aromatic aldehyde and Iodobenzene diacetate was tested in microfluidic chip reator with good yield. Compared to strongly exothermic batch reaction, it's mild, fast, and simple in chip.3. A Cu (â… )-catalyzed ligand-free three-component Click reaction of benzyl bromide, phenylacetylene and sodium azide was developed in microreactor. 50mol% sodium ascorbate was added as additive to prevent the oxidative coupling of desired poduct with terminal alkyne. Under optimized condition, 1,4-disubstituted-1,2,3-trizazoles were isolate with yield of 89-98%.4. 6-trifluoromethyl-1,3-oxazine derivatives were synthesized from isoquinoline, actylenedicarboxylate and aromatic trifluoro ketone via 1,4-dipolar cycloaddtion process in both batch and microfluidic system. In chip reaction, after only 9 minutes higher yield was obtained than 10 hours in flask, higher selectivity was also observed.5. Addition reaction of dichlorocarbene generated from sodium hydroxide and chloroform to alkene was carried out in microfluidic chip. With or without phase transfer catalyst, full conversion and up to 95% conversion of cyclohexene could be obtained while it's only 50-70% in batch system, the sharp contrast showed super high mixing efficiency in microchip.1,1-dichloro-cyclopropane derivatives were synthesized in high yield.