INVESTIGATIONS IN THE FIELD OF GROUP-14 DIFLUORENYL COMPOUNDS

Dimethyl(difluorenyl)silane, -germane and -stannane 1-3 are quantitati vely obtained by a one-pot synthesis from dimethyldichlorosilane, -ger mane and -stannane and two equivalents of fluorenyllithium. Monofluore nyl compounds 4 and 5 can also be obtained selectively using a stoichi ometric amount of fluorenyllithium. Addition of one or two equivalents of ($) under bar n-butyllithium to 1 or 2 affords selectively the cor responding monolithio or dilithio derivatives, respectively, which can be quenched by MeI, Me(3)SiCl or Me(2)SiCl(2). An NMR study shows the great influence of the second fluorenyl group on the chemical shifts of methyls bonded to metal, and on the hydrogen on C-9 of the fluoreny l group.