o-(Fluorodimethylsilyl)phenyllithium as a versatile reagent for preparation of unsymmetrical, silicon-functionalized o-disilylbenzenes

o-(Fluorodimethylsilyl)phenllithium (1) was prepared by bromine-lithium exchange between o-C6H4(SiMe2F)Br (2) and t-BuLi in Et2O at -78 degrees C The electrophilic Si-F fiinctionality in I is not attacked by the nucleophilic aryllithium moiety; at that temperature. Li-7, F-19, and Si-29 NMR analyses supported by DFT calculations suggested that the structure of I involves an intramolecular coordination of the fluorine substituent to the lithium atom. Reactions of 1 with halosilanes produced unsymmetrical, silicon-halogenated o-disilylbenzenes 4.