Synthesis of oxonium derivatives of the dodecahydro-closo-dodecaborate anion [B12H12]2-.: Tetramethylene oxonium derivative of [B12H12]2- as a convenient precursor for the synthesis of functional compounds for boron neutron capture therapy

Direct synthesis of oxonium derivatives of the dodecahydro-closo-dodecaborate anion is described and the reaction mechanism is discussed. Various derivatives of the [B12H12](2-) anion containing hydroxyl, amine, acid, and amino acid functions were prepared by ring opening reactions of the tetramethylene oxonium derivative [B12H11O(CH2)(4)](-) with different nucleophiles. This approach is suitable for the development of compounds to be used in tumour selective boron neutron capture therapy (BNCT) and as linkers for the attachment of radioactive halogen labels for radioimmunodetection and radioimmunotherapy. (C) 2000 Elsevier Science Ltd All rights reserved.