Stereoselective synthesis of 1,1-bimetalloalkenes of tin and selenium, tinand tellurium

1,1-Bimetalloalkenes(tin and selenium, tin and tellurium) were stereoselect ively prepared by a hydrozirconation of acetylenic stannanes followed by tr ansmetallation using tellurenyl iodide and selenenyl bromide. One equivalen t of n-BuLi displaced a trialkylstannyl group selectively and lithiated vin yl selenides were reacted with electrophiles to afford (E)-internal selenid es.