Authors:Runa B. Østby, Yngve H. Stenstrøm and Terje Didriksen
Conventional batch dibromocyclopropanations by reaction of bromoform and alkenes under phase-transfer conditions require strong base (50% NaOH (aq)), vigorous stirring, and often long reaction times. Using flow chemistry in a microreactor, the reactions were found to be smooth, rapid, and high-yielding under ambient conditions when 40% (w/w) NaOH was used as the base. The reaction has been tested with a representative selection of alkenes, displaying a variety of structural features.
Authors:Terje Didriksen, Aud I. Spjelkavik and Richard Blom
A continuous synthesis route of the metal—organic framework (MOF) CPO-27-Ni (also known as Ni2(dhtp), Ni/DOBDC or Ni-MOF-74) from aqueous solutions of the nickel acetate and sodium salt of the 2,5-dihydroxyterephtalate linker using tubular reactor techniques has been developed. When running the reaction at 90 °C, a conversion of above 90% is reached in just 20 min. The resulting MOF has a specific surface area (Brunauer—Emmett—Teller [BET]) of around 1085 m2/g and a powder X-ray diffraction pattern consistent with the known CPO-27-Ni structure. Scanning electron microscopy clearly shows that crystallite sizes around 40 nm are obtained when using the tubular reactor approach, while state-of-the-art batch synthesis in water typically gives micrometer-sized crystallites as product. The tubular reactor setup can be easily up-scaled by parallelization.