[C2B10]-[B12] double cage boron compounds -: a new approach to the synthesis of water-soluble boron-rich compounds for BNCT

A new approach in the synthesis of water-soluble boron-rich compounds was proposed. The closo-dodecaborate cage is used as a hydrophilic substitutent providing for the water-solubility of the molecule whereas the carborane cage can be used for attachment to biomolecules using earlier developed methods. The double-cage molecules [o-, m-, and p-CB(10)H(10)C(CH(2))(4)OB(12)H(11)](2-) were prepared by the reaction of the tetramethylene oxonium derivative of the closo-dodecaborate anion, [B(12)H(11)O(CH(2))(4)](-), with the corresponding lithiated carboranes. The compounds obtained have doubled the boron contents and could serve for the synthesis of agents for boron neutron capture therapy (BNCT). (C) 2003 Elsevier Science B.V. All rights reserved.