Synthesis and characterization of a novel functionalized azanonaborane cluster for boron neutron capture therapy

The reactivity of an azanonaborane cluster containing free amino groups {HN(CH)HNBH NH(CH)NH} towards ketones and aldehydes is investigated. In a one step reaction, the reductive amination of some ketones and aldehydes (namely acetone, benzaldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 4-nitrobenzaldehyde, 4-acetoxybenzaldehyde, and 4-acetamidobenzaldehyde) with an azanonaborane cluster in the presence of H BNH(CH)NH gives monoalkylamino derivatives of the azanonaborane cluster {RHN(CH )HNBHNH(CH )NHR} where (R = (Me)CH-, C HCH-, 3-OHCHCH -, 4-OHCHCH-, 4-NO CHCH-, 4-MeOCOC HCH-, or 4-NHCOC HCH-). The functionalized derivatives of the {BN} cluster can be used in boron neutron capture therapy for tumors (BNCT). Similarly, the reductive amination of 5-(4′-formylphenyl)- 10,15,20-triphenylporphyrin with the {BN} cluster gave a porphyrin bearing azanonaborane cluster, while a porphyrin dimer linked by an azanonaborane moiety was obtained following the same method, starting with a 2 : 1 molar ratio of porphyrin : {BN} cluster. 5,10,15,20- Tetraformylphenylporphyrin gave the chance to increase the percentage of boron in the resulting boronated porphyrin, which is considered an important factor for a BNCT delivery agent. With these compounds, the cell toxicity using V79 cells was carried out to determine whether these compounds would have favorable biological properties. © The Royal Society of Chemistry 2005.