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 it 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.