Reactivity of co-ordinated ligands. Part VIII. The preparation and reactivity of some rhodium(I) derivatives of tricyclo[5,2,1,02,6]deca-4,8-dien-3-one and tricyclo[6,2,1,02,7] undeca-4,9-diene-3,6-dione

Abstract

The preparation and reactions of cyclopentadienyl(tricyclo[5,2,1,02,6]deca-4,8-dien-3-one)rhodium(I), (dp)Rh(π-C5H5), and cyclopentadienyl(tricyclo[6,2,1,02,7]undeca-4,9-diene-3,6-dione)rhodium(I), (cq)Rh(π-C5H5) are described. Both complexes undergo several characteristic reactions of ketones. The ketone group of (dp)Rh(π-C5H5) undergoes nucleophilic attack by R– to give the corresponding alcohol, (π-C5H5)Rh{C10H10(OH)R}(R = H, Me, Pri, or CH2·CO2Me). These alcohols react with hexafluorophosphoric acid or triphenylmethyltetrafluoroborate to give the corresponding cations, [(π-C5H5)Rh(C10H10R)]+. The complex (cq)Rh(π-C5H5) reacts with sodium borohydride to give a diol, (π-C5H5)Rh(C11H14O2) and with methylmagnesium iodide to give the alcohol, (π-C5H5)Rh(C12H14O2). Reaction of these alcohols with hexafluorophosphoric acid or triphenylmethyl tetrafluoroborate gives cationic(dienyl) complexes of the type [(R2C5H5)Rh{C11H10R1(OH)}]BF4 and [(R2C5H4)Rh{C11H10R1(O)}] BF4(R1= R2= H; R1= H, R2= CPh3; R1= Me, R2= H).