Abstract A novel preparative route to perfluoroheteroalkenes F3CE [dbnd] CF2 (E= P, As) and E'[dbnd] CF2 (E'= S, Se) has been developed using the trimethyltin compounds Me2SnE (CF3) 2 and Me3SnE'CF3 as precursors. After a short information about the characterization of these heteroalkenes, the results of self-addition, HX-additon and [2+ 4] cycloaddition reactions of F3CP [dbnd] CF2 (1)[and in part of F3CAs [dbnd] CF2 (2)] are ...