text: A related family of reactions are the transmetalations, wherein two organometallic compounds exchange their metals. Many examples of such reactions involve lithium exchange with tin:
  :CHLi + MeSnAr → CHSnMe + LiAr  (where Ar is aryl and Me is methyl)
  The tin–lithium exchange reactions have one major advantage over the halogen–lithium exchanges for the preparation of organolithium reagents, in that the product tin compounds (CHSnMe in the example above) are much less reactive towards lithium reagents than are the halide products of the corresponding halogen–lithium exchanges (CHBr or CHCl). Other metals and metalloids which undergo such exchange reactions are organic compounds of mercury, selenium, and tellurium.