Coupling of 2-substituted 1-fluorovinylstannanes with organic halides catalyzed by palladium(0)/copper(I) iodide. A mild and stereospecific method tomonofluoroolefins

The palladium-catalyzed cross-coupling reactions of (E)- or (Z)-1-fluorovin ylstannanes with aryl iodides and vinyl iodides provide good yields of ster eoisomerically pure substituted fluoroolefins with retention of the double bond geometry. The reaction takes place with copper(I) iodide present as a cocatalyst at ambient temperature or in refluxing tetrahydrofuran and is to lerant of a variety of functional groups. Highly functionalized and stereoi somerically pure monofluorovinyl ketones also were obtained under mild cond itions by the coupling of 1-fluorovinylstannanes with acid chlorides. H-1-{ F-19} NOE NMR experiments unequivocally established the stereochemistry of the coupling products E-14 and Z-14.