Intramolecular syn and anti hydrosilylation and silicon-assisted cross-coupling: Highly regio- and stereoselective synthesis of trisubstituted allylic alcohols

[GRAPHIC] The geometrical isomers of 6-ethylidenedioxadisilacyclohexane were prepared by intramolecular hydrosilylation of an unsymmetrical disiloxane by the use of Pt (syn) and Ru (anti) catalysts. This new class organosilicon reagents underwent cross-coupling reactions with a range of aryl iodides to afford (E)- and (2)-trisubstituted allylic alcohols in a highly stereospecific fashion.