Bilayer Properties of 1,3-Diamidophospholipids

A series of 1,3-diamido phosphocholines was synthesized, and their potential to form stable bilayers was investigated. Large and giant unilamellar vesicles produced from these new lipids form a wide variety of faceted liposomes. Factors such as cooling rates and the careful choice of the liposome preparation method influence the formation of facets. Interdigitation was hypothesized as a main factor for the stabilization of facets and effectively monitored by small-angle X-ray scattering measurements

Large-Scale Synthesis and Resolution of TRISPHAT [Tris(tetrachlorobenzenediolato) phosphate(V)] Anion

Both enantiomers of TRISPHAT anion can be obtained on a multigram scale through a novel resolution procedure. The Lambda enantiomer is isolated as the tri-n-butylammonium salt, [(n)()Bu(3)NH][Lambda-1], which is soluble in pure CHCl(3) and CH(2)Cl(2). The Delta enantiomer is prepared as the cinchonidinium derivative, which is only soluble in polar solvent mixtures (>7.5% DMSO in CHCl(3))

Synthesis, Enantiomeric Conformations, and Stereodynamics of Aromatic ortho-Substituted Disulfones

Aromatic ortho-disulfone derivatives are readily accessible from diiodide precursors by Cu(I)-mediated reactions with sodium sulfinate salts. The sulfone substituents adopt C(2)-symmetric enantiomeric conformations (lambda and delta) as evidenced by X-ray structural analysis and (1)H and (31)P NMR on chiral bis(sulfonyl)veratrol derivatives and hexacoordinated tris(benzenediolato)phosphate anions. Slow dynamic conformational isomerism (DeltaG(++) > or = 19.8 kcal mol(-1)) was detected in solution

Synthesis, Enantiomeric Conformations, and Stereodynamics of Aromatic ortho-Substituted Disulfones

Aromatic ortho-disulfone derivatives are readily accessible from diiodide precursors by CuI-mediated reaction with sodium sulfinate salts (DMF, 110°). The sulfonyl substituents adopt in solution and in the solid state two enantiomeric conformations (? and d) as evidenced by 31P- and 1H-NMR data of the chiral D3-symmetric tris{4,5-bis[(4-methylphenyl)sulfonyl]benzene-1,2-diolato(2-)-?O,?O}phosphate(v) anion (3a) and 1,2-bis(camphor-10-sulfonyl)-4,5-dimethoxybenzene ((=1,2-bis{{[(1S,4R)-7,7-dimethyl-2-oxobicyclo[2.2.1]hept-1-yl]methyl}sulfonyl}-4,5-dimethoxybenzene; 6c). X-Ray structure analysis of 1,2-dimethoxy-4,5-bis(methylsulfonyl)benzene (6a) and 1,2-dimethoxy-4,5-bis(4-methylphenyl)sulfonyl]benzene (6b) confirmed in the solid state the preferred chiral orientation of the sulfonyl groups. Dynamic conformational isomerism was detected for 6c in its 1H-NMR in the temperature range of 110°, the corresponding free energy being 19.8 kcalmol-1