Fluorine-Containing Nitrogen Compounds. I. Trifluoroethylamines

Bissell, Eugene R.; Finger, M.

doi:10.1021/jo01091a024

Cited by 38 publications

(19 citation statements)

References 2 publications

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“…[12][13][14][15] Because perfluoroalkanethioamides can be easily obtained via thioacylation of amines, we devised a new route for the synthesis of perfluoroalkylmethyl-amines from these precursors. Thus, diborane generated in situ, 16 was reacted with 6a, 6b and (+)-6c to afford amines 7a, 17 7b 18 and (+)-7c, respectively (Scheme 2). 19…”

Section: Methodsmentioning

confidence: 99%

Methyl Perfluorooctanethionate as a Tool for Indirect Perfluoroalkylmethylation and Perfluoroalkylation of Amines

Kiss

Rábai

Varga

et al. 1998

Synlett

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Methyl perfluorooctanethionate 4 is a novel reagent for fluorophilization of amines and can be prepared effectively from ethyl 3-(perfluorooctylthio)propionate 3 in a one-pot procedure.The applications of two-phase catalysis for commercial bulk processes 1a as fluorous biphase systems for catalytic reactions, for engineered product separations, or for carrying out fluorous syntheses call for effective design and preparations of fluorophilic catalysts and reagents. 1b Since the phase preference is determined by the interactions at the molecular level, fluorophilic compounds must have an appropriate balance between the perfluorocarbon-like and other constituents in their molecules. At one extreme these molecules are fluorophilic (i.e. prefer to stay in the fluorocarbon phase) or at the other extreme are amphiphilic (fluorocarbon/water or fluorocarbon/hydrocarbon). 2 To quantify the extent of the fluorous phase preference of a compound, we define the term fluorophilicity (f) as f = ln P, where P is the partition coefficient between perfluoro(methylcyclohexane) and toluene phases at 25 o C (Table 1). 3 We wish to report, that thionoester 4 is a novel reagent for increasing the fluorophilicity of appropriate amines. Experimentally determined fluorophilicity data indicate, that the phase preference of the compounds shown here is highly sensitive to small differences in their molecular structures (cf. boiling point, fluorine content and f values, Table 1). Reagent 4, a longer chain alkyl perfluoroalkanethionate, was prepared as follows (Scheme 1). A mixture of perfluorooctyl iodide 1 and ethyl 3-mercaptopropionate 2 dissolved in liquid ammonia was UV-irradiated 4 to furnish ethyl (3-perfluorooctylthio)propionate 3. 5 Ester 3 was reacted with sodium hydride (reverse Michael, with loss of ethyl acrylate 6 ) in ether, then quenched with methanol to afford 4 in 59% yield. 7 Only short chain perfluoroalkanethionoesters and thionoacyl fluorides prepared under forcing reaction conditions are known hitherto 8 , while the synthesis of alkyl perfluoroalkanedithiocarboxylates of longer perfluoroalkyl chains has been reported recently. 9 Scheme 1The reaction of methyl perfluorooctanethionate 4 with a slight excess of an alkyl amine, such as morpholine (5a), dimethylamine (5b) and (+)-1-phenylethylamine ((+)-5c) results in the formation of the appropriate thioamides, 6a, 6b and (+)-6c, respectively, in high yields (Scheme 2). The present procedure could be a preferred alternative to the known thionation reactions of amides using phosphorus pentasulfide 10 or Lawesson's reagent. 11 Perfluoroalkyl-alkylamines are receiving much attention recently in the field of both homogeneous catalysis and synthesis. 12-15 Because perfluoroalkanethioamides can be easily obtained via thioacylation of amines, we devised a new route for the synthesis of perfluoroalkylmethyl-amines from these precursors. Thus, diborane generated in situ, 16 was reacted with 6a, 6b and (+)-6c to afford amines 7a, 17 7b 18 and (+)-7c, respectively (Scheme 2). 19 Scheme 2...

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Section: Methodsmentioning

confidence: 99%

Methyl Perfluorooctanethionate as a Tool for Indirect Perfluoroalkylmethylation and Perfluoroalkylation of Amines

Kiss

Rábai

Varga

et al. 1998

Synlett

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“…As a result of the successes seen in the reduction of 2,2,2-trifluoroacylamide with sodium borohydride, the reduction of polyHFPO nitrile was also attempted using sodium borohydride in the presence of trifluoroacetic acid. In comparison to the poor yields observed in the reduction of 2,2,2-trifluoroacylamide by Bissell and Finger (LiAlH 4 = 57.4%; NaBH 4 = 44.2%) [9], the reduction of the polyHFPO nitrile using sodium borohydride was much more effective, resulting in an 83% yield [13] with >99% conversion (Scheme 8).…”

Section: The Preparation Of Polyhfpo Nitrilementioning

confidence: 99%

“…As an extension of their work, in 1959 Bissel and Finger studied these reductions in more depth. In order to determine the most appropriate reducing agent for the reduction of substituted 2,2,2-trifluoroethylamides, Bissel and Finger www.elsevier.com/locate/fluor concluded that the use of sodium borohydride alone was insufficient for the reduction of full substituted amides [9]. Consequently, the reaction required the addition of either boron trifluoride etherate or aluminum chloride (see Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

“…The method employed in the synthesis of polyHFPO methylene amine is a multi-step synthesis that follows the method reminiscent of that of Bissel and Finger [9]. In this method, polyHFPO methyl ester (F[CF(CF 3 )CF 2 O] n CF(CF 3 )-C(O)OCH 3 ) is first synthesized by the methanolysis of polyHFPO acid fluoride (caution: hydrofluoric acid is produced).…”

Section: Introductionmentioning

confidence: 99%

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Understanding the influence of hydrocarbon insulators in fluorinated amines: Reactivity of poly(hexafluoropropylene oxide) amine containing methylene spacers

Friesen

Howell

Jamieson

et al. 2008

Journal of Fluorine Chemistry

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“…Being a strong Lewis acid, borane is expected to attack preferentially at centers of high electron density; ordinary amides are readily reduced to alkylamines, but trichloroacetaldehyde is not attacked to any great extent, nor are acyl chlorides (12), and it appeared worthwhile to examine whether selective reduction is possible in 18. The fact that trifluoroethylamines have been by reduction of trifluoroacetamides by use of mixtures of sodium borohydride and aluminum trichloride (or boron trifluoride), in which borane is believed to be the active reductant (13), militated against the proposition, but, on the other hand, we were encouraged by a series of model experiments that we performed. 1-Formamido-and 1 -trifluoroacetamido-1 -deoxy-D -x Y I~~o~ tetraacetates were treated with borane under identical conditions, and the results were evaluated by tlc and mass spectrometry.…”

Section: Syntheses Of ( -)-Hyosaminementioning

confidence: 99%

Enantiospecific syntheses of (+)-hyosamine and (−)-hyosamine

Baer¹,

Chen²,

Giziewicz³

1991

Can. J. Chem.

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. Can. J. Chem. 69,1563Chem. 69, (1991. Two constituent components of the stereoisomeric aminocyclitol antibiotics hygromycin B and destomycin A, namely, (+)-hyosamine and (-)-hyosamine ( 1~-and ID-(1 ,3/2,4,6)-4-amino-6-methylamino-l,2,3-cyclohexanetrio1 1 and 2, respectively) were synthesized independently in enantiospecific fashion from the common preparative precursor 3, 1~-(1,3/2,4,6)-6-azido-1,2-0-isopropylidene-4-nitro-1,2,3-cyclohexanetriol, which is conveniently accessible from D-mannose. The key strategy involved selective and sequential reduction of the nitrogenous functions in 3 to the amino stage and installation of an N-methyl group in appropriately blocked derivatives. Several variations based on this principle were examined, and one approach to 1 as well as two approaches to 2 were successfully completed. The target amines were characterized as their crystalline penta-N,O-acetyl derivatives 12 and 22.Key words: aminocyclitol antibiotics, enantiospecific syntheses of hyosamines, nitrogen-substituted 1,2,3-cyclohexanetnols. [Traduit par la rkdaction] Introduction The aminocyclitol antibiotics hygromycin B and destomycin A produced by Streptomyces hygroscopicus and Streptomyces rimofaciens, respectively, are diastereomers. Each consists of an amino-methylamino-cyclohexanetriol unit (an N-methyl-2-deoxystreptamine) to which is glycosidically linked the rare sugar D-talose, which, in turn, bears on its 0-2,O-3 positions a 6-amino-6-deoxyheptono-1,5-lactone, attached in orthoester fashion. The sole structural difference between the two antibiotics is the enantiotopic position of the N-methyl substituent in the diaminocyclitol(1). Thus, hygromycin B yields on hydrolysis the dextrorotatory fragment 1, termed (+)-hysamine ( 1~-(1,3/2,4,6)-4-amino-6-methylamino-1,2,3-cyclohexanetriol),

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Fluorine-Containing Nitrogen Compounds. I. Trifluoroethylamines

Cited by 38 publications

References 2 publications

Methyl Perfluorooctanethionate as a Tool for Indirect Perfluoroalkylmethylation and Perfluoroalkylation of Amines

Methyl Perfluorooctanethionate as a Tool for Indirect Perfluoroalkylmethylation and Perfluoroalkylation of Amines

Understanding the influence of hydrocarbon insulators in fluorinated amines: Reactivity of poly(hexafluoropropylene oxide) amine containing methylene spacers

Enantiospecific syntheses of (+)-hyosamine and (−)-hyosamine

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