Palladium(0)-catalyzed cross-coupling of potassium (Z)-2-chloroalk-1-enyl trifluoroborates: a chemo- and stereoselective access to (Z)-chloroolefins and trisubstituted alkenes.

We describe the preparation of a series of new potassium trifluoroborates 1 and the study of their behaviour in a Pd(0)-catalyzed cross-coupling reaction. We found that compounds 1 are endowed with original properties as they behave as nucleophilic cross-coupling partners chemoselectively but also as ambivalent synthons. The usefulness of this methodology has been successfully illustrated by the first total synthesis of an N-acyl spermidine.