Chemistry of unsaturated arenetricarbonylchromium compounds 1. Reaction of (η6-arene)tricarbonylchromium complexes of nitrones with methyl phenylpropiolate

The reactions of nitrones of the composition (CO)(3)CrC6H5CH=N+(O-)R (R = Me, Ph, or But) with substituted acetylene were studied. The reactions proceed with high regioselectivity and give 4-isoxazolines (yields 50-60%). The composition and structures of these products were characterized by physicochemical methods. The reactions also afford (eta(6)-benzaldehyde)tricarbonylchromium, coordinated Schiff bases, and azoxy derivatives as thermal decomposition products of the starting nitrones. The reactions of uncoordinated nitrones with methyl phenylpropiolate were also investigated. These reactions produce 4-isoxazolines along with cyclic substituted isoxazolinones.