Flow chemistry as green technology for the genesis and use of organometallic reagents in the synthesis of key building blocks and APIs – An update

A Universal Framework for Fast, Flexible and Fun(ctional) Autonomous Laboratories

“…Case Study 8: Lithium-halogen exchange reactions in flow Lithium-halogen exchange reactions are difficult to control and study since they are extremely fast and highly exothermic; the resulting reactive intermediates have short lifetimes and low solubility in most organic solvents. As a result, flash chemistry is generally utilized, which requires precise control of residence time [30]. Moreover, to avoid the cross contamination between different reaction conditions and reactor clogging due to low solubility of the intermediates, a robust start-up and cleaning protocol for the reactor is required.…”

Ultrasonic or Microwave Modified Continuous Flow Chemistry for the Synthesis of Tetrahydrocannabinol: Observing Effects of Various Solvents and Acids

“…While microwave irradiation addresses kinetic problems when relatively narrow flow channels create solid phase/solution phase mixing problems, sonication addresses kinetic problems by producing cavitation bubbles, where high temperatures and pressures are experienced within the microenvironment of the cavitation bubbles produced. As the ultrasound intensity increases, the reaction rate increases due to an increase in the number of cavitation bubbles and an increase in the temperature within the cavitation bubbles as depicted in Figure a. − The traditional method of heating heats the reaction mixture outside in, which can cause uneven heating and inconsistent reaction kinetics with the need for stirring. The microwave radiation provides deeper penetration and heats the solvent and sample evenly while maintaining consistent reaction kinetics, as depicted in Figure b .…”

Continuous flow reactions in the preparation of active pharmaceutical ingredients and fine chemicals

“…8 For example, important contributions concerning the continuous synthesis of APIs using reactive organometallic intermediates have been described. 9,10…”