Continuous flow reactors: a perspective

Design, fabrication and characterization of microreactors for high temperature syntheses

“…The heater design was developed on the basis of a radial and uniform distribution of temperature and trying to avoid a highly elevated heat point in the center of the platform. By defining seven laps of a gold-based screen-printed conductor (0.7 mm width, 8 µm height), a 13 External pads were defined on the top layer of the thermal platform to connect the embedded heater to an external electronic control set-up, since the high working temperatures associated to the microreactor avoids the surface integration of electronic devices involved by the control system. For temperature sensing and establishing the PID control feedback, a class A PT100 sensor was placed over the thermal platform trying to obtain the optimum xy-alignment with the microreactor zone, which was embedded in the modular microfluidic platform later attached.…”

“…Moreover, microfluidics represents a better option than conventional methodologies for the synthesis of compounds that require an inert atmosphere, since the environment can be completely controlled in a simple way inside the microfluidic channels. Indeed, the degradation of certain sensitive products can be better avoided inside microreactors [13]. Another relevant advantage is the possibility to automate the whole process through the use of pumps, valves and computer-controlled elements, which increases reproducibility and autonomy, reduces possible risks associated to hazardous reagents and provides realtime information regarding the reaction evolution.…”

“…Miniaturized systems offer additional advantages such as the significant reduction of reagents consumption, which is becoming of major importance due to environmental concerns, and safer conditions when reactions involve the manipulation of hazardous reagents. In recent years, microfluidic systems have been increasingly used for synthetic purposes due to the advantages that they confer and the evolution that they have suffered from simple basic devices to more complex systems [10,[13][14]. These systems not only can be directly attached to pre-treatment steps or analytical instruments (such as chromatographs or spectrophotometers) but also can integrate some of them, even monolithically [15][16].…”

Numbered-up gas–liquid micro/milli channels reactor with modular flow distributor

“…The high rates of mass and heat transfer, minimum axial dispersion and the high interfacial area allow micro/milli channel reactors to run highly exothermic, toxic or even explosive reactions safely, permitting greener routes for processing [1,2,3,4,5]. Microreactors are very attractive devices for many different applications [6,7,8,9].…”

Palladium-Catalyzed Suzuki–Miyaura Cross-Coupling in Continuous Flow

“…In the context of green chemistry, catalysis and alternative media, different cross-coupling reactions such as Suzuki-Miyaura in batch reactors have been developed in aqueous media or in water as sole green safer solvent via conventional heating or microwave irradiation [32][33][34][35][36][37][38][39][40][41][42][43]. Continuous flow chemistry as alternative technology offers significant processing advantages including improved thermal management, mixing control, application to a wider range of reaction conditions, scalability, energy efficiency, waste reduction, safety, use of heterogeneous catalysis, multistep synthesis and much more [44][45][46][47][48][49]. Two different reactors, micro and meso (or flow) reactors, exist and the devices depend on the channel In this report, the development of different reactors made with a perfluoroalkoxyalkane (PFA) tube having the inner diameter of 1 mm has been described [84].…”