SYNTHESIS AND REACTIVITY OF 1,2-DIHYDROXYARENE AND 1,4-DIHYDROXYARENE COMPLEXES OF CHROMIUM TRICARBONYL

Direct reaction of Me3Si protected 1,2- or 1,4-dihydroxyarenes with Cr(CO)6 affords fair to good yields of the corresponding Cr(CO)3 complexes (1a-4a) which were characterized by 1H and 13C NMR and IR spectroscopic measurements. Removal of the Me3Si protecting groups with KF·2H2O or HBF4·Et2O afforded the 1,2- or 1,4-dihydroxyarene complexes 1b-4b which were characterized in solution but their instability and air-sensitivity precluded their isolation. Proton transfer reactions were monitored by IR spectroscopy. The crystal structure of 2,3-(Me3Si)2C10H6Cr(CO)3 was determined in the space group P21/c with a = 11.019(4), b = 17.613(9), c = 11.843(4) Å, β = 105.11(3)°, V = 2219.0 Å3, Z = 4. This synthetic route provides access to the π-coordination chemistry of 1,2-dihydroxyarenes which cannot be prepared by direct interaction of the arene with Cr(CO)6. © 1990.