Myers Lithium-Halogen Exchange RLi + R'X Chem 115 H RX + R'Li Br Lithium-halogen exchange reactions are kinetically controlled The position of the equilibrium varies with the stabilities of the carbanion intermediates involved (sp >> sp2 >> sp3) H 1.1 eq n-BuLi H OEt Et2O, !80 °C Li H OEt Lau, K S.; Schlosser, M J Org Chem 1978, 43, 1595 n-PrLi + PhI n-PrI + PhLi 1:10,000 eq t-BuLi n-C8H17Br Br H3C Li I LiI I Keq