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 been investigated using the relatively unhindered complexes Me2Si(C5H3SiMe3)(2)YCH(TMS)(2) and [Cp(2)(TMS)LnMe](2) (Ln = Y, Lu). A nide variety of dienes and trienes bearing a number of functional groups were cyclized, affording silanes containing quaternary centers in a diastereoselective fashion and in good yield. The products can be oxidized using one of several different protocols, yielding alcohols for further functionalization.