Generation of allylic and benzylic organolithium compounds by fluorine-lithium exchange: reaction with electrophiles

The application of the naphthalene-catalysed lithiation methodology to ally lic and benzylic fluorides 1 led to the corresponding allylic and benzylic organolithium reagents, which, in the presence of different electrophiles ( Barbier-type reaction conditions), afforded the expected products 2 in mode rate yields. The procedure was useful for the transformation of primary, se condary and tertiary benzylic fluorides into the corresponding lithium deri vatives. When a two-step lithiation process was used (treatment of fluoride 1 with lithium and a catalytic amount of naphthalene, followed by addition of the electrophilic reagent), only Wurtz-type coupling products were form ed. (C) 2001 Elsevier Science B.V. All rights reserved.