Alkenylzirconocene compounds, which are easily prepared by the hydrozirconation of alkynes, have been very useful intermediates in organic synthe~ is.~-~ Hydrozirconation of terminal alkynes regio-and stereoselectively affords alkenylzirconocene compounds of type Even though compound I1 is formed in situ, it immediately isomerizes to I in the presence of C~~ ZIHC~.~.~~ Consequently, an alkenylzirconocene of type II cannot be obtained by ...
