Publications by authors named "Udo Dörfler"

4 Publications

  • Page 1 of 1

Macropolyhedral boron-containing cluster chemistry. A synthetic approach via the auto-fusion of [6,9-(SMe2)2-arachno-B10H12].

Dalton Trans 2006 Aug 17(31):3752-65. Epub 2006 Jul 17.

School of Chemistry of the University of Leeds, Leeds, England, UK LS2 9JT.

In an attempt to build up borane-based multicluster assemblies, thermolysis of [6,9-(SMe2)2-arachno-B10H12] 1 in inert hydrocarbon solution, followed by chromatographic separation, has resulted in the isolation not only of the previously established single-cluster product from this reaction, [5-(SMe2)-nido-B10H12] 2 (30%), but also the two two-cluster species [6,9-(SMe2)2-arachno-B10H11-1-(6-nido-B10H13)] 3 (20%) and [1,6-(nido-B10H13)2] 6 (ca. 0.5%) and the two three-cluster species [6,9-(SMe2)2-arachno-B10H10-1,5-(6-nido-B10H13)2] 4 (5%), characterized crystallographically, and [6,9-(SMe2)2-arachno-B10H10-1,3-(6-nido-B10H13)2] 5 (<1%), identified by NMR spectroscopy. An improved crystallographic investigation of [5-(SMe2)-nido-B10H12] 2 is also presented. The feasibility of the stability of species resulting from multiple adjacent substitution of nido-decaboranyl units on the [6,9-(SMe2)2-arachno-B10H12] skeleton is tested by DFT calculations. In an extension, to attempt the use of pre--linked two-cluster compounds as starting substrates, two-cluster [5-(SMe2)-4-(2-nido-B10H13)-nido-B10H11] 7 (0.6%) has been isolated from the reaction of SMe2 with [1,5-(nido-B10H13)2], other identified products being compound 1 (39%) and compound 3 (10.5%).
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http://dx.doi.org/10.1039/b604295cDOI Listing
August 2006

Synthesis of (aminoalkylamine)-N-aminoalkyl)azanonaborane(11) derivatives for boron neutron capture therapy.

J Med Chem 2002 Dec;45(26):5817-9

Department of Chemistry, University of Bremen, P.O. Box 330440, D-28334 Bremen, Germany.

New boron-containing polyamine have been synthesized: (aminoalkylamine)-N-(aminoalkyl)azanonaborane(11) derivatives [H(2)N(CH(2))(n)H(2)NB(8)H(11)NH(CH(2))(n)NH(2)], where n = 4-6 and 12, and [H(2)N(CH(2))(3)H(2)NB(8)H(11)NH(CH(2))(4)NH(2)]. (4-Aminobutylamine)-N-(4-aminobutyl)azanonaborane and (3-aminopropylamine)-N-(4-aminobutyl)azanonaborane were less toxic in vitro (LD(50) of approximately 700 and approximately 1100 microM, respectively) than spermine, while (4-aminobutylamine)-N-isopropylazanonaborane with its hydrophobic isopropyl group and those with n = 5, 6, and 12 were already toxic under similar conditions (LD(50) < 500 microM). These compounds may be useful as delivery agents for boron neutron capture therapy.
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http://dx.doi.org/10.1021/jm020971kDOI Listing
December 2002

Azanonaboranes [(RNH(2))B(8)H(11)NHR] as possible new compounds for use in boron neutron capture therapy.

Eur J Med Chem 2002 Aug;37(8):649-57

Department of Chemistry, University of Bremen, D-28334 Bremen, Germany.

The synthesis and biological in vitro and in vivo activities of possible new compounds for Boron Neutron Capture Therapy (BNCT) are reported. The azanonaboranes of the type [(RNH(2))B(8)H(11)NHR] are water-soluble when hydrophilic groups are introduced. The reaction of B(9)H(13)SMe(2) with primary amines yields azanonaboranes. Five compounds with different numbers of hydroxypropyl groups have been isolated: [(HO(CH(2))(3)NH(2))B(8)H(11)NHCH(3)] (4), [(HO(CH(2))(3)NH(2))B(8)H(11)NH(CH(2))(3)OH] (2), [((HO(CH(2))(3))(2)NH)B(8)H(11)NHCH(3)] (6), [((HO(CH(2))(3))(2)NH)B(8)H(11)NH(CH(2))(3)OCH(3)] (11) and [((HO(CH(2))(3))(2)NH)B(8)H(11)NH(CH(2))(3)OH] (8). In vitro experiments as judged by cloning survival tests showed that two of the synthesised compounds are not toxic. The in vivo experiments were carried out with C3H/He mice bearing SCCVII tumours and C57 mice bearing B16 tumours. Compounds 2 and 6 have no particular affinity to any tissue, but are excluded from the brain.
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http://dx.doi.org/10.1016/s0223-5234(02)01383-1DOI Listing
August 2002