 The resultant vinyl or alkyl zirconium species can undergo a reversible, but stereoretentive transmetalation with an organoaluminum to provide the carboalumination product and regeneration of the zirconcene dichloride catalyst.This process generally provides the syn-addition product; however, conditions exist to provide the anti-addition product though a modified mechanism.Trimethyl Silyl (TMS) protected alkynes, trimethyl germanium alkynes, and terminal alkynes can produce anti-carboalumination products at room temperature or elevated temperatures if a coordinating group is nearby on the substrate.