DIRECT NITRATION OF ARYL GROUPS SIGMA-BOUND TO RUTHENIUM(II)

A new method has been developed for the preparation of nitroaryl trans ition metal complexes using copper(II) nitrate in the presence of acet ic anhydride (Menke conditions) to directly nitrate an aryl group whic h is already sigma-bound to a transition metal centre. Under these con ditions ruthenium(II) aryl complexes of the type: [GRAPHICS] (where R1 = R2 = H; R1 = H, R2 = CH3; R1 = CH3, R2 = H) react to yield three di stinct types of nitroaryl-containing products (I-III). [GRAPHICS] The preparation and characterisation of these compounds are described. X-r ay crystallographic data for one example of each of the three types of compound, are also reported. The compounds that have been studied cry stallographically are Ru(C6H4NO2-4)(eta2-O2CCH3)(CO)(PPh3)2 (1a), C45H 37NO5P2Ru.(CH2Cl2)0.5, a=20.254(5), b=19.437(8), c=22.629(3) angstrom, beta=115.390(10)-degrees, monoclinic, space group C2/c, Z=8; Ru-(C6H4 N(O]O-2)-Cl(CO)(PPh3)2 (4a), C43H34ClNO3P2Ru, a=9.331(3), b=12.443(2), c=16.346(3) angstrom, alpha=82.81(2), beta=85.03(2), gamma=74.76(2)-d egrees, triclinic, space group P1BAR, Z=2; Ru(C6H2CH3-2,NO2-4,N[O]O-6) Cl(CO)(PPh3)2 (5b), C44H35Cl-N2O5P2Ru.(CH2Cl2)2, a=19.497(3), b=14.502 (3), c=19.340(5) angstrom, beta=122.79(1)-degrees, monoclinic, space g roup Cc, Z=4.