Synthesis and characterization of tri-block fluorinated-n-alkanes

A series of triblock semifluorinated n-alkanes of general formula F(CF₂)_n(CH₂)_m(CF₂)_nF (n = 6, 8 and m = 4, 6, 8) have been synthesized and characterized. The synthesis of triblock compounds was performed in two different ways according to the length of the hydrogenated moiety. Coupling of two molecules of β-(perfluoro-n-alkyl)ethyl iodides leads to the triblock materials F(CF₂)₆(CH₂)₄(CF₂)₆F and F(CF₂)₈(CH₂)₄(CF₂)₈F. The synthesis of compounds with larger hydrogenated part is accomplished in two steps by the addition of perfluoro-n-alkyl iodide F(CF₂)_nI to 1,5-hexadiene and 1,7-octadiene, respectively to give the diiodo-adducts which are subsequently deiodinated to the final triblock products F(CF₂)₆(CH₂)₆(CF₂)₆F, F(CF₂)₆(CH₂)₈(CF₂)₆F, F(CF₂)₈(CH₂)₆(CF₂)₈F and F(CF₂)₈(CH₂)₈(CF₂)₈F. The obtained triblock semifluorinated n-alkanes are characterized by low surface free energies with good lubricant properties usable as additives in ski-wax formulations.     

Interaction of polyhedral boron hydride anions [B10H10] and [B12H12] with cyclic copper and silver 3,5-bis(trifluoromethyl)pyrazolate complexes

The interactions of cyclic trinuclear copper {[3,5-(CF₃)₂Pz]Cu}₃ and silver {[3,5-(CF₃)₂Pz]Ag}₃ complexes with polyhedral borate anions [B₁₀H₁₀]²⁻ and [B₁₂H₁₂]²⁻ in solvents of low-polarity were studied using IR spectroscopy (190-290 K). Two types of complexes were found in solution: {[((3,5-CF₃)₂PzM)₃][B_nH_n]}²⁻ and {[((3,5-CF₃)₂PzM)₃]₂[B_nH_n]}²⁻ (M = Ag, Cu; n = 10, 12). The stability constants of these complexes were determined from IR-spectra.     

Fluorinated phosphorus compounds: Part 9. The reactions of bis(fluoroalkyl) phosphorochloridates with oxygen nucleophiles

Twenty nine bis(fluoroalkyl) phosphates (R_FO)₂P(O)OR were prepared in 18-75% yield by treating phosphorochloridates (R_FO)₂P(O)Cl, where R_F was HCF₂CH₂, HCF₂CF₂CH₂, H(CF₂)₄CH₂, C₂F₅CH₂, C₃F₇CH₂, (CF₃)₂CH, (FCH₂)₂CH and (CH₃)₂CF₃C with methanol, ethanol, propanol and isopropanol in diethyl ether in the presence of triethylamine. The bulky chloridate [(CH₃)₂CF₃CO]₂P(O)Cl reacted with methanol, ethanol and propanol, but not with isopropanol - even on heating in the presence of the catalyst 4-dimethylaminopyridine - due to steric hindrance at phosphorus. The relative reactivities of three of the chloridates decreased in the order [(CF₃)₂CHO]₂P(O)Cl > [(FCH₂)₂CHO]₂P(O)Cl > [(CH₃)₂CF₃CO]₂P(O)Cl. Also described is the synthesis of phosphates (CF₃CH₂O)₂P(O)OCH₂R, where R = CH₂Br, CH₂Cl, CH₂F and CHF₂, and diphosphates [H(CF₂)_nCH₂O]₂P(O)OCH₂(CF₂)₂CH₂OP(O)[OCH₂(CF₂)_nH]₂, where n = 1, 2 and 4.     

Synthesis of novel lipophilic and/or fluorophilic ethers of perfluoro-tert-butyl alcohol, perfluoropinacol and hexafluoroacetone hydrate via a Mitsunobu reaction: Typical cases of ideal product separation

Fluorophilic ethers having the structure RC(CF₃)₂O(CH₂)₃C_nF_2n + 1 are obtained in high yields, when F-tert-butyl alcohol (R = CF₃), F-acetone hydrate (R = O(CH₂)₃C_nF_2n + 1), F-pinacol (R = C(CF₃)₂O(CH₂)₃C_nF_2n + 1) are reacted with 3-perfluoroalkyl-1-propanols (C_nF_2n + 1(CH₂)₃OH, n = 4, 6, 8, 10) in a Mitsunobu reaction (Ph₃P/DIAD [i-PrO₂CN = NCO₂Pr-i]/ether). The parent lipophilic ethers with the structure of (CF₃)₃CO(CH₂)₃C_nH_2n + 1 were prepared analogously using the corresponding fatty alcohols and F-tert-butyl alcohol. To achieve ideal separations, products were transferred to orthogonal phases relative to the other reaction components using fluorous extraction, fluorous solid-organic liquid filtration, or steam-distillation. Selected physical properties including melting and boiling point, together with fluorous partition coefficients of these ethers were determined and the figures obtained were qualitatively analyzed using relevant thermodynamic theories. Some of these ethers are liquids with rather low freezing points and are miscible with fluorocarbon solvents.     

Analysis of pyrolysis products formed from ethylene-tetrafluoroethylene heterosequences of poly(ethylene-co-tetrafluoroethylene)

Poly(ethylene-co-tetrafluoroethylene) (PETFE) was pyrolyzed and the pyrolysis products formed from the ethylene-tetrafluoroethylene heterosequences were analyzed using gas chromatography/mass spectrometry (GC/MS). Major pyrolysis products were 3,3-difluoropropene (DFP), 3,3,4,4-tetrafluoro-1-butene (TFB), 1,1,2,2,3,3-hexafluorocyclopentane (HFCP), 1,1,2,2,3,3-hexafluorocyclohexane (HFCH), 1,1,2,2,3,3,4,4-octafluorocyclohexane (OFCH), and 3-trifluoromethyl-3,4,4,5,5-pentafluorocyclohexene (FMPFCH). Their formation mechanisms were proposed. Peak intensity ratios of HFCP, HFCH, and FMPFCH compared to OFCH increased as the pyrolysis temperature increased, while those of DFP, TFB, HFCP, and HFCH compared to tetrafluoroethylene decreased. Order of the relative abundances of the major pyrolysis products formed from PETFE was OFCH > HFCP > HFCH > TFB > DFP. The order may be due to the difference in bond energies of CH₂-CH₂, CF₂-CH₂, and CF₂-CF₂. Formation of the pyrolysis product through the CH₂-CH₂ bond cleavage was more favorable than those through the CF₂-CH₂ and CF₂-CF₂ ones.     

Synthesis and characterization of partially fluorinated ethers

A series of partially fluorinated ethers PFE-m,n with general formula F(CF₂)_mCH₂CH₂O(CH₂)_nH (m = 4, 6, 8 and n = 2, 3, 5, 8, 14, 18, 21) has been synthesized and characterized. The present work aimed to investigate the synthesis of PFE-m,n and evaluate some of their fundamental physico-chemical properties such as: specific gravity, refractive index, viscosity, solid-solid transitions, solubility and amphiphile surface activity in a variety of solvents. Further, a comparison between PFE-m,n and the well known semifluorinated n-alkanes F(CF₂)_m-(CH₂)nH (FHm, n) with the same value of the m/n ratio have been reported.     

Synthesis and properties of gemini-type hydrocarbon-fluorocarbon hybrid surfactants

Gemini-type hybrid surfactants with two fluorocarbon chains connected through a hydrocarbon spacer, F(CF₂)_m(CH₂)₂CH(OSO₃Na)(CH₂)_nCH(OSO₃Na)(CH₂)₂(CF₂)_mF [Fm(Hn)FmOS, m = 4, 6; n = 5, 6, 7, 8)], were synthesized and their surface chemical properties were examined with the aim to have highly functional and highly water-soluble fluorinated surfactants when compared with the conventional fluorinated surfactants. Comparisons of the surface chemical properties of the synthesized gemini-type hybrid surfactants with those of monounit-type hybrid surfactants, F(CF₂)_m(CH₂)₂CH(OSO₃Na)(CH₂)_nH [FmEHnOS, m = 4, 6; n = 3, 5)], revealed that gemination causes a remarkable lowering (about 1/100) in cmc value while it produces little changes in Krafft point (below 0 °C) and surface tension at cmc (γ_cmc).     

Site directed synthesis of mono and disubstituted SF5-polyfluoroalkyl benzenes

A novel method for the preparation of o-, m-, p-SF₅CF₂CFYC₆H₄X (Y = Br, F and X = m-Br, p-Br, Cl, CH₃, CF₃, NO₂, o-NO₂, F, CF₃, CH(CH₃)₂) derivatives was devised by a two-step reaction: SF₅Br-addition to o-, m-, p-CF₂CFC₆H₄X followed by reaction of AgBF₄ with the o-, m-, p-SF₅CF₂CFBrC₆H₄X adducts. Additional studies have been carried out with several derivatives and includes the preparation of SF₅CF₂C(O)C₆H₅, p-CF₃CFBrC₆H₄NO₂, SF₅CF₂CF₂C₆H₃(NO₂)₂, SF₅CF₂CF₂C₆H₃(NH₂)₂, and an SF₅CF₂CF₂-containing polyimide and dye. The complete characterization (IR, NMR, and MS) of these compounds is given.     

Iodomethane oxidative addition to β-diketonatobis(triphenylphosphite)rhodium(I) complexes: A synthetic, kinetic and computational study

New rhodium(I)- and rhodium(III)-β-diketonato complexes of the type [Rh(FcCOCHCOR)(P(OPh)₃)₂] and [Rh(FcCOCHCOR)(P(OPh)₃)₂(CH₃)(I)], with Fc = ferrocenyl and R = Fc, CH₃ and CF₃, have been synthesized. The reactivity of complexes of the type [Rh(β-diketonato)(P(OPh)₃)₂] increase in the order: β-diketonato = (CF₃COCHCOCF₃)⁻ < (CF₃COCHCOPh)⁻ < (CF₃COCHCOCH₃)⁻ < (PhCOCHCOPh)⁻ < (CF₃COCHCOFc)⁻ < (CH₃COCHCOPh)⁻ < (CH₃COCHCOCH₃)⁻ < (CH₃COCHCOFc)⁻ < (FcCOCHCOFc)⁻, giving linear relationships between the kinetic parameter ln k₂ and the parameters that are related to the electron density on the rhodium centre; the sum of the group electronegativities of the β-diketonato side groups (χ_R + χ_R′) and the pK_a of the uncoordinated β-diketone RCOCH₂COR′. The large negative values of the volume and entropy of activation indicated a mechanism which occurs via a polar transition state. A density functional theory study, at the PW91/TZP level of theory, indicates that oxidative addition of iodo methane to [Rh(FcCOCHCOCF₃)(P(OCH₃)₃)₂] occurs via a two-step mechanism. This mechanism involves a nucleophilic attack by the metal on the methyl carbon to displace iodide to form a metal-carbon bond and the coordination of iodide to the five-coordinated intermediate to give a six-coordinated trans alkyl product.     

Novel generation ponytails in fluorous chemistry: Syntheses of primary, secondary, and tertiary (nonafluoro-tert-butyloxy)ethyl amines

(Nonafluoro-tert-butyloxy)ethyl tosylate 4 was prepared in 65% yield from nonafluoro-tert-butanol 1 using commercially available reagents. Further reaction of 4 with HNR¹R² (R¹ = R² = H, CH₃; R¹ = H, R² = CH₃, (CH₂)₃C₈F₁₇, CH₂CH₂OC(CF₃)₃) affords the appropriate (CF₃)₃COCH₂CH₂NR¹R² amines in 20-69% yields. Improved overall yields of [(CF₃)₃COCH₂CH₂]_3−nNR_n to 1 were obtained by the reaction of (CF₃)₃CONa 2 and (XCH₂CH₂)_3−nNR_n (X = Cl, n = 0, 1, 2, R = CH₃; X = CH₃SO₂O, n = 1, R = CH₃SO₂) nitrogen mustards and a similar reactive β-substituted ethyl amine. The title amines are mobile colorless liquids and volatile with steam. The bulky fluorous ponytail (CF₃)₃CO(CH₂)₂ displays high acidic stability and increases fluorous character almost as much as the classical straight-chain C₈F₁₇(CH₂)₃ ponytail.     

Preparation of ferrocenes with high fluorous-phase affinities

The reaction of 1,1′-bis(pentafluorophenyl)ferrocene with fluorous alkoxides having the general formula NaOCH₂(CF₂)_nCF₃ (n = 0, 2, 5, 7, and 8) afforded a series of ferrocenes of general formula {η⁵-4-[CF₃(CF₂)_nCH₂O]C₆F₄C₅H₄}₂Fe (1). The reaction of 1,1′-bis(4-tetrafluoropyridyl)ferrocene with the same fluorous alkoxides afforded a series of ferrocenes of general formula (η⁵-4-{2,6-[CF₃(CF₂)_nCH₂O]₂C₅F₂N}C₅H₄)₂Fe (2). Perfluoro(methylcyclohexane)/toluene partition coefficients increase with the number (2 or 4) and length (n) of the fluorous substituent. Complexes 1a and 2a (both n = 0) were structurally characterized.     

Differentiation of isomeric allylic alkenyl methyl ethers by Raman spectroscopy

The Raman spectra of several pairs of alkenyl methyl ethers of general structure R¹R²CCR⁵C(R³R⁴)OCH₃ and R¹R²C(OCH₃)C(R⁵)CR³R⁴ (R¹, R², R³, R⁴, R⁵ = H or C_nH_2n+1, n = 1-3) are reported and discussed, with a view to establishing whether Raman spectroscopy offers a viable means of distinguishing between these isomeric unsaturated species. Key bands associated with the ν(sp₂CH) and ν(CC) stretching modes are found to be particularly useful in this connection: R¹R²CCHCH₂OCH₃ and R¹R²C(OCH₃)CHCH₂ ethers (R¹, R² = CH₃, C₂H₅) are easily distinguished on this basis. Differentiation of their lower homologues, R¹CHCHCH₂OCH₃ and R¹CH(OCH₃)CHCH₂ (R¹ = CH₃, C₂H₅, C₃H₇), by similar means is also quite straightforward, even in cases where cis and trans isomers are possible. Pairs of isomeric ethers, such as CH₃CHC(CH₃)CH₂OCH₃ and CH₃CH(OCH₃)C(CH₃)CH₂, in which the structural differences are more subtle, may also be distinguished with care. Deductions based on bands ascribed to the stretching vibrations are usually confirmed by consideration of the signals associated with the corresponding δ(sp₂CH) deformation vibrations. Even C₂H₅CHCHCH(C₃H₇)OCH₃ and C₃H₇CHCHCH(C₂H₅)OCH₃ are found to have distinctive Raman spectra, but differentiation of these closely related isomers requires additional consideration of the low wavenumber region.     

New types of asymmetrical bromonium salts [RF(RF′)Br]Y where RF and/or RF′ represent perfluorinated aryl, alkenyl, and alkynyl groups

A series of previously unknown asymmetrical fluorinated bis(aryl)bromonium, alkenyl(aryl)bromonium, and alkynyl(aryl)bromonium salts was prepared by reactions of C₆F₅BrF₂ or 4-CF₃C₆H₄BrF₂ with aryl group transfer reagents Ar′SiF₃ (Ar′ = C₆F₅, 4-FC₆H₄, C₆H₅) or perfluoroorganyl group transfer reagents R_F′BF₂ (R_F = C₆F₅, trans-CF₃CFCF, C₃F₇C≡C) preferentially in weakly coordinating solvents (CCl₃F, CCl₂FCClF₂, CH₂Cl₂, CF₃CH₂CHF₂ (PFP), CF₃CH₂CF₂CH₃ (PFB)). The presence of the base MeCN and the influence of the adducts R_F′BF₂·NCMe (R_F = C₆F₅, CF₃C≡C) on reactions aside to bromonium salt formation are discussed. Reactions of C₆F₅BrF₂ with Alk_F′BF₂ in PFP gave mainly C₆F₅Br and Alk_F′F (Alk_F′ = C₆F₁₃, C₆F₁₃CH₂CH₂), presumably, deriving from the unstable salts [C₆F₅(Alk_F′)Br]Y (Y = [Alk_F′BF₃]⁻). Prototypical reactivities of selected bromonium salts were investigated with the nucleophile I^-and the electrophile H⁺. [4-CF₃C₆H₄(C₆F₅)Br][BF₄] showed the conversion into 4-CF₃C₆H₄Br and C₆F₅I when reacted with [Bu₄N]I in MeCN. Perfluoroalkynylbromonium salts [C_nF_2n+1C≡C(R_F)Br][BF₄] slowly added HF when dissolved in aHF and formed [Z-C_nF_2n+1CFCH(R_F)Br][BF₄].     

Branched and dendritic metallo-carbosiloxanes with OCH2PPh2MLn end-grafted units

A straightforward method for the preparation of metallo carbosiloxanes of type Si(OCH₂CH₂CH₂SiMe₂[OCH₂PPh₂M(CO)_n])₄ (n = 3, M = Ni, 7a; n = 4, M = Fe, 7b; n = 5: M = Mo, 7c; M = W, 7d), Si(OCH₂CH₂CH₂SiMe[OCH₂PPh₂Ni(CO)₃]₂)₄ (8) and Me₂Si(OCH₂CH₂CH₂SiMe[OCH₂PPh₂Ni(CO)₃]₂)₂ (11) is described. The reaction of Si(OCH₂CH₂CH₂SiMeXCl)₄ (1: X = Me, 2: X = Cl) or Me₂Si(OCH₂CH₂CH₂SiMeCl₂)₂ (9) with HOCH₂PPh₂ (3) produces Si(OCH₂CH₂CH₂SiMe₂(OCH₂PPh₂))₄ (4), Si(OCH₂CH₂CH₂SiMe(OCH₂PPh₂)₂)₄ (5) or Me₂Si(OCH₂CH₂CH₂SiMe(OCH₂PPh₂)₂)₂ (10) in presence of DABCO. Treatment of the latter molecules with Ni(CO)₄ (6a), Fe₂(CO)₉ (6b), M(CO)₅(Thf) (6c: M = Mo; 6d: M = W), respectively, gives the title compounds 7a-7d, 8 and 11 in which the PPh₂ groups are datively bound to a 16-valence-electron metal carbonyl fragment.The formation of analytical pure and uniform branched and dendritic metallo carbosiloxanes is based on elemental analysis, and IR, ¹H, ¹³C{¹H}, ²⁹Si{¹H} and ³¹P{¹H} NMR spectroscopic studies. In addition, ESI-TOF mass spectrometric studies were carried out.     

Fluorous modification of 2,2′-bipyridine

A series of 2,2′-bipyridines featuring fluorinated alkyl groups [(CH₂)₃(CF₂)_xCF₃: x = 0, (1); 5, (2); 7, (3); 9 (4)] appended in the 4 and 4′ positions have been prepared. 1-4 were characterized by spectroscopy and physical methods including partition coefficient (biphase: perfluoromethylcyclohexane/toluene) and cyclic voltammetry (THF). Ab-initio calculations of vertical ionization potentials (VIPs) for 1-4 confirm the insulating role of the methylene spacers as the electrochemical reduction potentials of 1-4 are almost identical to that of 2,2′-bipyridine. Calculations for (CH₂)_nCF₃ derivatives (n = 0-10) describe a limit for impact of the CF₃ group through 9-10 methylenes. From both physical and theoretical data fluorinated alkyl groups of the formula (CH₂)₃(CF₂)_xCF₃ [x = 0-9] are inductively equivalent to a hydrogen substituent when appended to the bipyridine moiety.     

Halogen displacement chemistry with silver and alkali metal salts: Preparation of SF5-esters, alcohols, aliphatic olefins, acids and an iodide

It has been found that treatment of SF₅-alkyl halides, especially SF₅(CH₂)₂Br, with silver salts such as CH₃C(O)OAg, p-CH₃C₆H₄SO₃Ag, CF₃SO₃Ag and AgNO₃ provides convenient pathways for preparing the following ester compounds: SF₅CH₂CH₂R (R = CH₃COO, TosO, CF₃SO₃, NO₃), SF₅(CH₂)₃OTos, and SF₅(CF₂)₄(CH₂)₂OAc. Important derivatives prepared from these esters include SF₅(CH₂)₂OH; SF₅(CF₂)₄(CH₂)₂OH. Several alkenes SF₅C(Br)CH₂ and SF₅CH₂(COOCH₃)CCHC(O)OCH₃ are obtained using silver salts. The use of alkali metals salts with SF₅(CH₂)₃Br is studied and yields SF₅(CH₂)₃I; also, a pathway has been developed that extends for SF₅(CH₂)₃₋ the chain by two-carbon atoms and also produces the first SF₅-containing malonic acid.     

Synthesis and repellent properties of vinylidene fluoride-containing polyacrylates

Fluorinated polyacrylats with side group containing vinylidene fluoride (VDF) units (CF₃(CF₂)_n (CH₂CF₂)_m, n = 3, 5; m = 1, 2) were successfully synthesized. The water and oil repellency properties of these polymers are similar to those of fluorinated polyacrylate with side group containing long perfluorooctyl group (CF₃(CF₂)₇). The thermal telomerization of CF₃(CF₂)₅I and CF₃(CF₂)₃I with vinylidene fluoride (VDF) provided CF₃(CF₂)₅CH₂CF₂I (1b) and CF₃(CF₂)₃CH₂CF₂CH₂CF₂I (1c), respectively. The addition of 1b with ethylene followed by hydrolysis gave CF₃(CF₂)₅CH₂CF₂CH₂CH₂OH (2b). Treatment of 1c with ethyl vinyl ether in the presence of Na₂S₂O₄ followed by reduction produced CF₃(CF₂)₃CH₂CF₂CH₂CF₂CH₂CH₂OH (2c). Fluoroacrylates 3b-d were prepared by acrylation of the corresponding fluoroalcohols 2b-d. The semi-continuous process emulsion co-polymerization of 3a-d with octadecyl acrylate and 2-hydroxylethyl acrylate initiated by (NH₄)₂S₂O₈ in the presence of a mixture emulsifiers of polyoxyethylene(10)nonyl phenyl ether (TX-10) and sodium lauryl sulfate provided stable latexes 4a-d, respectively. The water and oil repellency properties of 4b (R_f: CF₃(CF₂)₅CH₂CF₂) and 4c (R_f: CF₃(CF₂)₃CH₂CF₂CH₂CF₂) containing vinylidene fluoride (VDF) units were similar to those of 4a (R_f: CF₃(CF₂)₇) containing long perfluoroalkyl group and much better than those of polymer 4d (R_f: CF₃(CF₂)₃) with short perfluoroalkyl chain. Thus, polyacrylates containing vinylidene fluoride units showed promising aspects as the alternatives to the currently used water and oil repellent agents with long perfluoroalkyl chains.     

Synthesis of polyphosphazenes bearing alkoxyethoxy and trifluoroethoxy groups

The synthesis of various phosphoranimines including (CH₃OCH₂CH₂O) (CF₃CH₂O)₂P?N? Si(CH₃)₃, (CH₃OCH₂CH₂OCH₂CH₂O) (CF₃CH₂O)₂P?N? Si (CH₃)₃, (CH₃OCH₂CH₂O)₂(CF₃CH₂O) P?N? Si(CH₃)₃, and (CH₃OCH₂CH₂OCH₂CH₂O)(CF₃CH₂O) P?N? Si(CH₃)₃ via the Staudinger reaction of (CH₃)₃SiN₃ with the suitably substituted phosphite is reported. These monomers were polymerized using tetra-n-butylammonium fluoride and N-methylimidazole in various solvents at several temperatures. In situ ³¹P-NMR kinetic studies and M_n versus time studies were also performed for the monomers to understand the propagation mechanism. © 1994 John Wiley & Sons, Inc.     

Fluorinated phosphorus compounds: Part 11. The reactions of some fluorinated amines with dialkyl and bis(fluoroalkyl) phosphorochloridates

Dimethyl phosphorochloridate reacted with R_FCH₂NH₂ in ether in the presence of Et₃N to afford (MeO)₂P(O)NHCH₂R_F, where R_F = CF₃ and C₂F₅, in 39 and 47% yield, respectively. Similar reactions with di-n-propyl and diisopropyl phosphorochloridates could be effected only with H₂NCH₂CF₃ when 4-dimethylaminopyridine catalyst was added and (n-PrO)₂P(O)NHCH₂CF₃ and (i-PrO)₂P(O)NHCH₂CF₃ were isolated in 49 and 25% yield, respectively. Treatment of POCl₃ with one molar equivalent each of H₂NCH₂CF₃ and Et₃N permitted the synthesis of Cl₂P(O)NHCH₂CF₃ in 43% yield. Bis(fluoroalkyl) phosphorochloridates (R_FO)₂P(O)Cl, where R_F = C₂F₅CH₂, C₃F₇CH₂ and (CF₃)₂CH, reacted with 2,2,2-trifluoroethylamine and 2,2,3,3,3-pentafluoropropylamine to furnish phosphoramidates (R_FO)₂P(O)NHCH₂R, where R = CF₃ or C₂F₅, in yields of 32-67%.     

Synthesis and characterization of fluorous (S)- and (R)-1-phenylethylamines that effect heat facilitated resolution of (±)-2-(8-carboxy-1-naphthylsulfinyl)benzoic acid via diastereomeric salt formation and study of their circular dichroism

Perfluoroalkyl- or nonafluoro-tert-butoxy-alkyl-substituted enantiopure amines having the structure PhCHCH₃(NR¹R²) [R¹ = H, CH₃; R² = (CH₂)₃C₈F₁₇, (CH₂)₂OC(CF₃)₃; R¹ = R² = (CH₂)₃C₈F₁₇, (CH₂)₂OC(CF₃)₃] are obtained in high yields, when (S)-(−)-1-phenylethylamine is reacted with readily accessible alkylating reagents or fluorous 2° amines (R¹ = H; R² = (CH₂)₃C₈F₁₇, (CH₂)₂OC(CF₃)₃) are methylated in a Leuckart-Wallach reaction. The solubility patterns of these novel chiral amines and their hydrochlorides are qualitatively described for a broad spectrum of solvents and the fluorous partition coefficients of the free bases are determined by GC. A novel method for the resolution of enantiomers is disclosed here, which involves the use a half-equivalent of the selected resolving agent in solvent water that displays low solubility for the crystalline diastereomeric salt(s) formed even at temperatures near to its boiling point. Compound (S)-(−)-PhCHCH₃[NH(CH₂)₃C₈F₁₇] is found to satisfy all the latter conditions and successfully used for the heat facilitated resolution of the title racemic acid. The circular dichroism (CD) spectra of six novel fluorous (S)-(−)-1-phenylethylamine derivatives are measured in ethanol, trifluoroethanol and hexafluoropropan-2-ol and discussed in detail.