Hydration with mercuric acetate and the reduction with 9-BBN-H of 2-(1-alkenyl)-4,6-dimethyl-s-triazines.

Oxymercuration-demercuration of a double bond in conjugation with the 4,6-dimethyl-s-triazin-2-yl substituent as in alkenes 1a,b gave anti-Markovnikov regioselectivity, which is explained by the electron-withdrawing nature of the triazinyl substituent. However, hydroboration of the conjugated alkenes with 9-BBN-H gave the corresponding alkanes 5a-c under normal workup conditions with or without oxidation. With time and without workup the hydroboration of 1b gave spectral evidence for the formation of intermediates 9-13 resulting from the migration of the 9-BBN moiety from the alpha-carbon to a ring nitrogen with concurrent formation of an exocyclic double bond to an alpha-carbon of the ring.

The synthesis and characterization of bis-substituted derivatives of the [a2-B20H18]4- anion and the interconversion of isomers.

The apical-apical (a2) isomer of [Et4N]4[B20H18] reacts with oxalyl chloride in dichloromethane to produce a protonated bis-substituted carbonyl species, [Et4N][a2-B20H17(CO)2] ([Et4N][H1]), in 60% yield. Removal of the bridging hydrogen of the [H1]- anion in aprotic media results in rearrangement to form the equatorial-equatorial [e2-B20H16(CO)2]2- anion ([e2-1]2-). The reaction of [Et4N][H1] with sodium azide in acetonitrile produces [Et4N]3- [a2-B20H17(NCO)2] ([Et4N]3[H2]) in 53% yield, which subsequently reacts with isopropylamine in acetonitrile to provide the urea derivative [a2-B20H16(NH2C(O)NH(i-Pr))2]2- ([Et4N]2[4]) in 89% yield.

Model studies directed toward the application of boron neutron capture therapy to rheumatoid arthritis: boron delivery by liposomes in rat collagen-induced arthritis.

The application of boron neutron capture therapy to rheumatoid arthritis requires the selective delivery of the boron-10 isotope to the synovitic tissue. The use of liposomes as a boron delivery method has been explored through the measurement of the time course biodistribution of boron in rats with collagen-induced arthritis (CIA). Small unilamellar vesicles were composed of a 1:1 mixture of distearoylphosphatidylcholine and cholesterol, incorporated K[nido-7-CH3(CH2)15-7,8-C2B9H11] as an addend in the lipid bilayer and encapsulated Na3[a2-B20H17NH2CH2CH2NH2] in the aqueous core.