Abstract
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.