CATALYTIC CYCLIZATION SILYLATION OF DIENES CONTAINING 1,1-DISUBSTITUTED OLEFINS USING ORGANOLANTHANIDE AND GROUP-3 ORGANOMETALLIC COMPLEXES/

The catalytic cyclization/silylation reaction of hindered dienes has b een investigated using the relatively unhindered complexes Me2Si(C5H3S iMe3)(2)YCH(TMS)(2) and [Cp(2)(TMS)LnMe](2) (Ln = Y, Lu). A nide varie ty of dienes and trienes bearing a number of functional groups were cy clized, affording silanes containing quaternary centers in a diastereo selective fashion and in good yield. The products can be oxidized usin g one of several different protocols, yielding alcohols for further fu nctionalization.