Acid catalysed condensation reactions of 1,3-dihydroxybenzene with new redox-active metallocene aldehydes

Article abstract of DOI:10.1016/0022-328X(95)05911-8

New ferrocene and cobaltocenium acetal and aldehyde containing compounds have been prepared. The acid catalysed condensations of both metallocene bis(aldehydes) (5, 6) with 1,3-dihydroxybenzene yielded complex products. The new metallocene cyclic monoaldehydes (7, 8), differed markedly in their reactions with 1,3-dihydroxybenzene with the ferrocene derivative 8 producing [1 + 1] and [1 + 2] bisphenol: aldehyde adducts, whereas the cobaltocenium analogue gave a cyclic diene compound (16). A single crystal X-ray structure of 16 is also described and the electrochemical properties of some of the new metallocene derivatives reported.