Promoted by metallic cadmium allylilic and propargyl bromides react smoothl
y with aldehydes in aqueous DMF to give homoallylic and homopropargyl alcoh
ols in moderate to good yields. It can also promote pinacol coupling of aro
matic aldehydes. The metallic cadmium is produced in situ by the reduction
of CdCl2 . H2O with samarium metal.