Generation and reactions of transient 9-silaphenanthrene derivative

Generation and reaction of a 9-silaphenanthrene derivative, a novel class o f silaaromatic intermediates, by a thermal retro-ene elimination of propene from the corresponding allylsilane is described. The formation of the tran sient 9-silaphenanthrene was deduced by the isolation of trapping products from the copyrolysate of the 9-allyl-9,10-dihydro-9-silaphenanthrene deriva tive with MeOD.