Catalytic Amidation of 9-Iodo-m-carborane and 2-Iodo-p-carborane at a Boron Atom

The palladium-catalyzed amidation of B-iodocarboranes by various amides is described for the first time. The reactions of 2-iodo-1,12-dicarba-closo-dodecaborane (2-iodo-p-carborane) with acetamide, 2-pyrrolidinone, caprolactam, p-methylbenzamide, and 2-phenylacetamide using the system Pd(dba)2/BINAP/NaH (dba = dibenzylideneacetone; BINAP = rac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) in dioxane at 100 °C gave 2-p-carboranyl derivatives of these amides in good to high yields. Similar reactions of 9-iodo-1,7-dicarba-closo-dodecaborane (9-iodo-m-carborane) with corresponding amides afforded 9-m-carboranyl derivatives in good to high yields. The structures of N-(1,12-dicarba-closo-dodecaboran-2-yl)pyrrolidin-2-one (5), N-(1,7-dicarba-closo-dodecaboran-9-yl)acetamide (6), and N-(1,7-dicarba-closo-dodecaboran-9-yl)-2-phenylacetamide (7) have been established by X-ray diffraction studies.