Motohiro Mitani

Synthesis and surfactant properties of novel acrylic acid co-oligomers containing fluoroalkylated end-groups: a new approach to polymeric inhibitors of human immunodeficiency virus type-1

Abstract Reactions of fluoroalkanoyl peroxides with acrylic acid, and with alkyl methacrylates or trimethylvinylsilane, give a series of new fluoroalkylated acrylic acid/alkyl methacrylate and /trimethylvinylsilane co-oligomers in excellent to moderate yield under very mild conditions. Fluoroalkylated acrylic acid/alkyl methacrylate co-oligomers are soluble in common organic solvents such as methanol, DMSO and tetrahydrofuran, and slightly soluble in non-polar aromatic solvents such as benzene, toluene and xylene. However, these co-oligomers do not have good solubility in both water and aromatic solvents. In contrast, fluoroakylated acrylic acid/trimethylvinylsilane co-oligomers are readily soluble in not only in water but also in common organic solvent such as methanol, ethanol, tetrahydrofuran, carbon tetrachloride, chloroform, DMF, DMSO, benzene, toluene and xylene. This feature is due to the trimethylsilyl side-chains possessing good oleophilic properties. Fluoroalkylated co-oligomers, in particular fluoroalkylated acrylic acid/trimethylvinylsilane co-oligomers, reduce the surface tension of both water and m -xylene effectively to around 15–20 mN m −1 , the same as for low-molecular weight fluorinated surfactants, though the co-oligomers have high molecular weights. These fluoroalkylated silicon-containing co-oligomers exhibit a clear break point resembling a CMC, which suggest that they form intra- or inter-molecular aggregations in aqueous solutions owing to their unique structure (fluoroalkylated end-capped structure). The fluoroalkylated acrylic acid co-oligomers inhibit HIV-1 induced cytopathogenesis. Relative to dextran sulfate, superior anti-HIV-1 activity could be obtained with fluoroalkylated acrylic acid/trimethylvinylsilane co-oligomers; however, fluoroalkylated acrylic acid cooligomers containing hydroxy groups were inactive. An obvious correlation exists between anti-HIV-1 activity and the hydrophilic or lipophilic property of these co-oligomers, i.e. they provide a most adequate HLB value for anti-HIV-1 activity. More hydrophilic or more oleophilic fluoroalkylated co-oligomers were less active (or inactive), suggesting that more hydrophilic or more oleophilic fluoroalkylated co-oligomers have a weaker effect on the interaction between gp/120 (or gp41) in HIV-1 and CD4 receptors. In fluoroalkylated silicon co-oligomers, as the degree of the reduction in surface tension of water becomes higher the anti-HIV-1 activity becomes higher, suggesting that the more adsorbable co-oligomers at the water/air interface have a higher anti-HIV-1 activity. A new correlation between anti-HIV-1 activity and properties of fluoroalkylated acrylic acid co-oligomers is indicated, affording a useful new strategy for exploring potent new polymeric inhibitors of HIV-1.

Synthesis and surfactant properties of novel fluoroalkylated allyl- and diallylammonium chloride oligomers

Abstract New fluoroalkylated allyl- and diallylammonium chloride oligomers with carbon—carbon bond formation have been prepared by the oligomerization of allylammonium chloride and the cyclo-oligomerization of diallylammonium chloride by the use of fluoroalkanoyl peroxides, respectively. These obtained fluoroalkylated cationic oligomers were able to reduce the surface tension of water to around 10 mN m−1, and are applicable to new cationic oligosurfactants containing fluoroalkyl groups.

Chemiluminescence of Cypridina luciferin analogues. Part 1. Effect of pH on rates of spontaneous autoxidation of CLA in aqueous buffer solutions

From the pH–rate profile of autoxidation of the Cypridina luciferin analogue {2-methyl-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one, CLA}, CLA was found not to react with ground-state molecular oxygen at a measurable rate, while the conjugate base of CLA was found to react with molecular oxygen with a second-order rate constant of 0.434 ± 0.001 dm3 mol–1 s–1 at 25 °C. No chain reaction process contributed in the autoxidation of CLA. Superoxide dismutase (SOD) was observed to reduce the rate of the autoxidation to a small extent in the reaction with low-pH buffers, while SOD did not affect the reaction in buffers of pH higher than 7. The intimate radical pair (CLA˙O2˙–) is proposed to be the primary product of the reaction.

Synthesis and surfactant properties of novel acrylic acid oligomers containing perfluoro-oxa-alkylene units: an approach to anti-human immunodeficiency virus type-1 agents

Abstract A new polymeric perfluoro-oxa-alkane diacyl peroxide has been prepared by the reaction of the corresponding perfluoro-oxa-alkane diacid fluoride and hydrogen peroxide under alkaline conditions. The decomposition behavior of this peroxide was quite similar to those of the fluoroalkanoyl peroxides [(RFCOO2)2; RF = perfiuoroalkyl and perfluoro-oxa-alkyl groups]. This peroxide decomposed homolytically with decarboxylation to afford the -RF- unit and, in addition, was useful for the introduction of the perfluoro-oxa-alkylene (-RF-) unit into acrylic acid homo- and co-oligomers via a radical process. These new acrylic acid oligomers containing the perfluoro-oxa-alkylene unit were shown to be soluble in water, methanol, ethanol, and tetrahydrofuran and were not only able to reduce the surface tension of water effectively but also to confer a good oil repellency. Furthermore, acrylic acid co-oligomers containing this perfluoro-oxa-alkylene unit were found to be potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) in vitro.

Synthesis and properties of fluoroalkylated vinyl alcohol oligomers

Abstract New fluoroalkylated vinyl alcohol oligomers were prepared by the alcoholysis of the corresponding fluoroalkylated vinyl acetate oligomers, which were obtained by the reactions of fluoroalkanoyl peroxides with vinyl acetate. These vinyl alcohol oligomers exhibited a quite different solubility from non-fluorinated poly(vinyl alcohol).

Synthesis and properties of novel fluoroalkylated allyl alcohol oligomers

Abstract Allyl alcohol and allyl alcohol containing the polyoxyethylene unit were found to react with fluoroalkanoyl peroxides to afford the corresponding fluoroalkylated allyl alcohol oligomers via a radical process under very mild conditions. In particular, fluoroalkylated allyl alcohol oligomers containing the polyoxyethylene unit were shown to be effective in reducing the surface tension of water, and to be applicable for new non-ionic fluorinated amphiphiles.

Metastable ion study of fluorinated organic compounds. Part 3. α, α, α-trifluoroanisole and α, α, α-trifluorocresols

Abstract The spontaneous unimolecular dissociation reactions of the molecular ions of the C7H5F3O positional isomers α, α, α-trifluoroanisole (1), o-α, α, α,-trifluorocresol (2) and m-α, α, α-trilfluorocresol (3), have been investigated by mass-analyzed ion kinetic energy (MIKE) spectrometry and deuterium-labellin. The results are compared with those of the non-fluorinated analogues anisole (4), o-cresol (5) and m-cresol (6). Ions 1.+ and 4.+ fragment in an analogue fashion yielding MIKE spectra which are characteristically different from those isaomers of the isomers 2.+, 3.+, 5.+ and 6.+ whose MIKE spectra are closely similar, the fluorinated analogues 2.+ and 2.+ have different characteristics. This is because a pronounced ortho-effect is operative in 2.+.

Perfluoroalkylation of azo compounds

Abstract Perfluoroalkyl azo dyes were prepared by the reaction of azo compounds with bis(perfluoroalkanoyl) peroxides. The absorption spectra and melting points of the perfluoroalkyl azo dyes were also examined.

Synthesis of a novel polymeric perfluoro-oxa-alkane diacyl peroxide. A convenient tool for the introduction of the perfluoro-oxa-alkylene unit

A new polymeric perfluoro-oxa-alkane diacyl peroxide was prepared by the reaction of the corresponding perfluoro-oxa-alkane diacid fluoride and hydrogen peroxide, and this peroxide was shown to be useful for the introduction of the perfluoro-oxa-alkylene unit into acrylic acid oligomers.