Stereoselective Synthesis of (E)- and (Z)-Fluoroalkenylboronates Using 2-Fluoroalkylideneiodonium Ylides Generated from (2-Fluoro-1-alkenyl)iodonium Salts

(E)- and (Z)-(fluoroalkenyl)boronates were prepared stereospecifically by the reaction of 2-fluoroalkylideneiodonium ylide generated from (E)- or (Z)-(2-fluoroalkenyl)iodonium salts with di(p-fluorophenoxy)alkylboranes, followed by transesterification to pinacol esters. The resulting pinacol esters of (fluoroalkenyl)boranes were used for the stereoselective synthesis of trisubstituted fluoroalkenes by cross-coupling reactions.