Boron−Oxygen Bond Formation by Palladium-Catalyzed Etheration of 2-Iodo-<i>para</i>-carborane

Abstract

For the first time, the palladium-catalyzed etheration of 2-iodo- p -carborane with phenolates and alkoxides has been demonstrated. The reactions of 2-iodo-1,12-dicarba- closo -dodecaborane (2-iodo- p -carborane) with sodium salts of phenol, p -cresol, α- and β-naphthol, 3-methyl-4-chlorophenol, and 3,4-dimethylphenol using the Pd(dba) 2 /BINAP (dba = dibenzylideneacetone; BINAP = rac -2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) system in dioxane at 90 °C afforded the corresponding 2- p -carboranyl aryl ethers in good to high yields. 2-Methoxy- p -carborane and 2-ethoxy- p -carborane have also been obtained in good yield. The structures of 2-(4-methylphenoxy)- p -carborane and 2-methoxy- p -carborane have been established by X-ray diffraction studies.