The oxidative addition of MeI to the Ir(I) square-planar complex IrI(CO)((R)-(+)-BINAP) where (R)-(+)-BINAP = (R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl)) results in the formation of two diastereomers in a 2:1 ratio of the Ir(III) oxidative addition product IrI(2)(CO)(Me)((R)-(+)-BINAP) (4a and 4b) in a 85% overall yield. Upon iodide abstraction from the diastereomeric mixture with 2 equiv of AgSbF(6) in the presence of diethyl isopropylidene malonate (DIM), two diastereomers of the dicationic complex [Ir(CO)(Me)(DIM)((R)-(+)-BINAP)][SbF(6)](2) (5) are formed in a 90% yield with a ratio of 9:1. One diastereomer of the diiodide complex 4 and one diastereomer of the dicationic complex 5 have been characterized by X-ray diffraction. An anion exchange reaction of 5 with NaBAr(4)(f-) (BAr(4)(f-) = B(3,5-(CF(3))(2)C(6)H(3))(4)) affords [Ir(CO)(Me)(DIM)((R)-(+)-BINAP)][BAr(4)(f)](2) (6) in quantitative yield. Both 5 and 6 are active Lewis acid catalysts for the polarized Nazarov cyclization and the Diels-Alder reaction. In the Nazarov cyclization, when NaBAr(4)(f) is added as a cofactor for the reaction catalyzed by 5 or 6, the resultant oxyallyl cation intermediate from the 4pi conrotation undergoes a Wagner-Meerwein rearrangement to afford spirocyclic cyclopentenones in modest to good yields.