New synthesis of polyfluoroalkyl racemic α-amino acids

Delon, L.; Laurent, Philippe; Blancou, H.

doi:10.1016/j.jfluchem.2005.07.013

Cited by 11 publications

(7 citation statements)

References 39 publications

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“…Radical reactions using AIBN as initiator generally proceed in high yields, and the purification of the crude product is usually easy. The choice of the solvent is also critical to mediate iodofluoroalkylation in good yield . Whereas some authors proscribe the use of solvents in such reactions, in our case, due to the solid state of the glucosylated olefins and their possible degradation at high temperatures, we used THF as reaction solvent.…”

Section: Resultsmentioning

confidence: 99%

Propyl-Ended Hemifluorinated Surfactants: Synthesis and Self-Assembling Properties

2011

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The advantages of using hemifluorinated surfactants as an efficient alternative to detergents for manipulating membrane proteins in aqueous solution have been demonstrated in recent reports. However, the large-scale synthesis of these surfactants is still considered as a major matter and has limited their use for biochemical purposes. We report herein the synthesis of a novel series of perfluorohexane-based surfactants endowed with a short propyl hydrocarbon tip and whose polar head size is modulated by the presence of two or three glucose moieties. The synthetic route is based on the radical addition of two alkenes onto the 1,6-diiodoperfluorohexane using AIBN as a radical initiator, affording the surfactants in satisfactory overall yields. The self-assembling properties of these hemifluorinated surfactants were studied by surface tension measurements, dynamic light scattering, as well as their behavior upon reversed-phase chromatography and were compared with those of their perfluorinated analogues. Our findings strongly suggest the predominant influence of the propyl tip on both adsorption and micellization phenomena as well as on the hydrophobic character of the surfactants, whereas as previously observed, the shorter ethyl tip does not greatly affect these properties when compared to the perfluorinated analogues. Moreover, all the surfactants reported here self-assemble into small and monodisperse aggregates, a feature of crucial importance for biochemistry applications.

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Section: Resultsmentioning

confidence: 99%

Propyl-Ended Hemifluorinated Surfactants: Synthesis and Self-Assembling Properties

2011

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“…Other common radical initiators such as Pd(PPh 3 ) 4 , dibenzoyl peroxide, and AIBN also require high temperatures and often give low yields. We chose instead to use triethylborane as a catalyst, which has been shown to catalyze the addition reaction at low temperatures, but which has not gained widespread use for the preparation of semifluorinated chains. ,, This method proved to be highly effective, resulting in quantitative addition of the perfluoroalkyl iodides to the ω-alken-1-ols to give the iodo-substituted semifluoroalcohols, 1 , at temperatures as low as −20 °C within 2 h. Conversion of 1 to the semifluoroalcohol 2 was achieved via reductive deiodination using sodium borohydride in dry DMSO.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Properties of Amphiphilic Poly(1,4-Phenylene Ethynylene)s Bearing Alkyl and Semifluoroalkyl Substituents

Woody¹,

Nambiar²,

Brizius³

et al. 2009

Macromolecules

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New poly(1,4-phenylene ethynylenes)s (PPEs), in which each phenylene unit is substituted with both semifluoroalkoxy (-O(CH 2 ) m (CF 2 ) n F) and dodecyloxy (-O(CH 2 ) 12 H) groups, are amphiphilic by virtue of the self-aggregating properties of the dissimilar side chains. Sonogashira polymerization of 4-iodophenylacetylenes bearing semifluoroalkoxy and alkoxy groups in the 2-and 5-positions, respectively, affords polymers with regular relative placement of the dissimilar side chains (i.e., "regioregular" materials containing only "head-to-tail" diads). This provides a Janus type structure. The assembly of these polymers was studied as a function of the length of the fluoroalkyl segment in the side chain by X-ray diffraction, differential scanning calorimetry, and UV-vis spectroscopy. The properties of these polymers were compared to analogues with random relative placement of side chains (i.e., materials containing a mixture of "head-to-head", "tail-to-tail" and "head-to-tail" diads), and to a nonfluorinated analogue. In contrast to the highly ordered and oriented solid phases formed by alkyl/semifluoroalkyl substituted poly(bithiophene)s, and despite their defined molecular structure, the amphiphilicity of the new semifluoro PPEs impedes their crystallization. While the overall structure of the regioregular polymer is amphiphilic, in which the dissimilar side chains are expected to segregate, we ascribe the lack of crystallinity to the disruption of side chain crystallization by virtue of having the alkyl and fluoroalkyl segments within a single side chain. These side chain cannot pack in an interdigitated fashion by virtue of the disparate segments, thereby leading to poorly ordered, or amorphous, solid materials.

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“…However, they can be cleaved under certain conditions. For example, silyl enol ethers of ketones reacted with CF 3 I and Et 2 Zn in the presence of RhCl(PPh 3 ) 3 in DME to give a-trifluoromethyl ketones in good yields [1].…”

Section: Introductionmentioning

confidence: 99%

“…The radical addition of perfluoroalkyl iodides to ethyl-2-carbethoxy-2-phthalimido-pent-4-enoate can be initiated by Et 3 B/O 2 at room temperature [3]. And reactions between CF 3 X (X = Cl, Br, I) and tetrafluoroethylene, catalyzed by aluminum chlorofluoride, afford the corresponding compounds CF 3 CF 2 CF 2 X [4].…”

Section: Introductionmentioning

confidence: 99%