formation of organozincreagents and subsequent cross-coupling with aryl halides and activated carboxylic acids is reported. Formation of organozincreagents is achieved by pumping organic halides, in the presence of ZnCl2 and LiCl, through an activated Mg-packed column under flow conditions. This method provides efficient in situ formation of aryl, primary, secondary, and tertiary alkyl organozinc reagents