Oxidation of ferrocenyl ketones using selenium(IV) oxide: Crystal and molecular structures of racemic 2,3-diferrocenyl-1,4-diphenylbutane-1,4-dione, racemic and meso 2,3-diferrocenyl-1,4-bis(4-biphenylyl) butane-1,4-dione, and ferrocenylmethyl(4-biphenylyl) ketone

Article abstract of DOI:10.1016/S0022-328X(97)00293-3

Oxidation of the ferrocenyl ketones FcCH₂COR 1 [Fc = (C₅H₅)Fe(C₅H₄); a R = Ph, b R = C₆H₄Ph-4] with selenium(IV) oxide provides only modest yields of the corresponding 1,2-diketones FcCOCOR 2, but substantial yields of the 1,4-butanediones RCOCH(Fc)CH(Fc)COR 3 resulting from C-C coupling. Compounds 3 exist in two diastereoisomeric forms, racemic and meso, and crystal structures are reported for rac-3a, rac-3b and meso-3b, as well as for 1b.