Abstract
Carbometalation of alkynylsilanes with titanocene dichloride/dialkylaluminum chloride is stereospecifically cis. The alkenyltitanium intermediate can be stereospecifically protonated by aqueous sodium hydroxide or iodinated. Addition of any Lewis base to the alkenyltitanium intermediate induces decomposition of this intermediate to give an alkene by hydrogen atom abstraction from the medium, with loss of stereochemistry.