Isocyanate deinsertion from kappa(1)-O amidates: facile access to perfluoroaryl rhodium(I) complexes

Reaction of the amidate ligand salt, Na{[}N(Dipp)C(O)C6F5] (1) (Dipp = 2,6-diisopropylphenyl) with {[}Rh(NBD)Cl] (2) (NBD = norbornadiene) results in formation of the dirhodium(I) complex {[}Rh2\{mu(2)-N,O-N(Dipp) C(O)C6F5\} (2)(NBD)(2)] (2). Reaction of 2 with PCy3 at room temperature provides an equilibrium mixture of the geometric isomers (E/Z)-{[}Rh\{kappa(1)-O-N(Dipp)C(O)C6F5\}(NBD)(PCy3)] (E/Z-3). Treatment of 2 with 3 equiv. of CNXyl (Xyl = 2,6-dimethylphenyl) gives the kappa(1)-O complex {[}Rh\{kappa(1)-O-N(Dipp)C(O)C6F5\}(CNXyl)(3)] (6) while use of 3 equiv. of PPh3 provides the kappa(2)-complex {[}Rh\{kappa(2)-N,O-N(Dipp)C(O)C6F5\}(PPh3)(2)] (8). For complex. 2-N, O 8, an equilibrium results with free PPh3 giving the kappa(1)-O complex {[} Rh\{kappa(1)-O-N(Dipp)C(O)C6F5\}( PPh3)(3)] (9). Heating a tol-d(8) solution of E/Z-3, 6, or 8/9 results in 2,6-diisopropylphenylisocyanate extrusion providing the corresponding {[}Rh]-C6F5 complex in good yield.