ANCILLARY LIGAND-CONTROLLED SELECTIVITY FOR METAL OR CYCLOPENTADIENYLRING FLUOROALKYLATION IN REACTIONS OF FLUOROALKYL IODIDES WITH CYCLOPENTADIENYLRHODIUM COMPLEXES

Reactions of [Rh(eta(5)-C5H5)(CO)(2)] with isomeric primary and second ary fluoroalkyl iodides proceed by selective fluoroalkylation at the m etal center to give [Rh(eta(5)-C5H5)(CO)(R(F))I], and treatment of the se compounds with excess PMe(3) affords cationic fluoroalkyl complexes [Rh(eta(5)-C5H5)(PMe(3))(2)(R(F))]I-+(-). In contrast, reactions of [ Rh(eta(5)-C5H5)(PMe(3))(2)] with the same fluoroalkyl iodides proceed with completely different selectivity to afford ring-exo-fluoroalkylat ed products [Rh(eta(4)-C(5)H(5)R(F))(PMe(3))(2)I], which, in turn, rea ct with Ag+BF4- to give the cationic hydride complexes [Rh(eta(5)-C(5) H(4)R(F))(PMe(3))(2)H](+)[BF4](-).