Reactivity of (NHC)2FeX2 Complexes toward Arylborane Lewis Acids and Arylboronates

(NHC)(2)FeCl2 complexes undergo methoxide transfer in preference to aryl transfer from [(Aryl)B(OR)(3)](-), while addition of ArylBY(2) (Y = Cl, OR) to (NHC)Fe-methoxide compounds leads only to formation of (NHC)BY(2)Aryl. The addition of PhBCl2 to (NHC)(2)FeX2 compounds is introduced as a method for probing NHC dissociation from iron. Two expanded ring NHCs also undergo dissociation from iron in the respective (NHC)(2)FeCl2 complexes.