The synthesis of perfluoro(alkyletherphenyl) phosphines

The first perfluorophenyl substituted phosphine, C₆F₅)₃P was prepared by Wall et al. [1]. Since then numerous pentafluorophenylphosphorous compounds [2] have been prepared and their properties studied. Substituted perfluorophenylphosphines (R_fC₆F₄)₃P however not been extensively studied. Those that have been reported are all solids: (C₆F₅)₃P, m.p. 116° [1]; (p-CF₃C₆F₄)₃P, m.p. 103-105° [3]; (p-C₈F₁₇C₆F₄)₃P m.p. 117° [3]; and (p-C₆F₅OC₆F₄)₃P, m.p. 135-137° [4].     

Facile synthesis of 5-(α-alkyl-substituted) furans

2-Halo, 2-hydroxy- or 2-alkoxyalkyl substituted furans are easily synthesized under acidic conditions by intramolecular cyclization of α,β-unsaturated 1,4-diketones by a simple and cheap procedure. Some aspects of the mechanism are discussed.     

Reactions of perfluoro(2-methylpent-2-ene) and perfluoro(5-azanon-4-ene) with primary amines containing a 2,6-di-tert-butylphenol fragment

Reactions of perfluoro(2-methylpent-2-ene) and perfluoro(5-azanon-4-ene) with 4-(2-aminoethyl)-2,6-di-tert-butylphenol and 4-(3-aminopropyl)-2,6-di-tert-butylphenol in acetonitrile in the presence of triethylamine gave the corresponding azetidine, 1,2-dihydroazete, and 1,2-dihydro-1,3-diazete derivatives, respectively. The reaction mechanisms, role of triethylamine, and factors affecting the intramolecular nucleophilic cyclization process are discussed.     

Standard enthalpies of formation of perfluoro(2-methyl-3-oxa)hexanoic and perfluoro(2,5-dimethyl-3,6-dioxa)nonanoic acids

The energies of combustion of perfluoro(2-methyl-3-oxa)hexanoic and perfluoro(2,5-dimethyl-3,6-dioxa)nonanoic acids are for the first time measured in a calorimeter with a rotating platinized bomb and used to calculate the standard enthalpies of formation of these compounds in the liquid state. Based on the enthalpies of formation, the contribution from the [-CF₂OCF(CF₃)-] group to the enthalpies of formation of perfluoro acids is calculated.     

Electrophilic alkenylation of fluoroolefins by perfluoro(2-alkoxypropenes)

Perfluoro(2-alkoxypropenes) react with tetrafluoroethylene under mild conditions in the presence of SbF₅ to give the corresponding perfluoro(2-alkoxy-2-pentenes). 1-Trifluoromethoxyperfluoropropene is converted by the action of SbF₅ in SO₂ClF solution to the acid fluoride derivative of perfluoroacrylic acid.The authors express their deep gratitude to M. V. Galakhov for taking and interpreting the¹⁹F NMR spectra.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8. pp. 1926–1928, August, 1991.     

Asymmetric synthesis of 2-alkyl-substituted tetrahydroquinolines by an enantioselective aza-Michael reaction

An optically active tetrahydroquinoline intermediate (5) was prepared in 8 steps from monoprotected ethylene glycol, using a Pd-catalysed aza-Michael reaction to induce chirality. This can be transformed into three Galipea alkaloids (angustureine, galipeine and cuspareine). The proximity of a benzyloxy group is found to exert profound effects in several steps of the synthesis.     

The preparation of a novel 3-oxo-cyclopenten-2-phosphonate derivative,useful intermediate for 2-alkyl-substituted cyclopentenones synthesis.

Starting from a phosphonyl-furylcarbinol derivative, diethyl(l-methyl-3-oxo-cyclopenten-2-yl)phosphonate, first example of oxocyclopentenyl-phosphonate and useful intermediate for the synthesis of 2-alkylsubstituted cyclopentenones, has been prepared.     

Preparation and conformational properties of the perfluoro diether CF(3)OCF(2)OCF(2)C(O)F, a model molecule to study properties of perfluoro polyethers

The compound CF(3)OCF(2)OCF(2)C(O)F was prepared by oxidation of hexafluoropropene with molecular oxygen in the gas-phase using CF(3)OF as initiator. (13)C NMR, FTIR, Raman, UV-vis, and mass spectra were obtained and interpreted. The theoretical structure studies were performed by the calculation of the potential energy surfaces, using the results obtained for a smaller related molecule, CF(3)OCF(2)C(O)F, as a starting point. A high degree of conformational flexibility of this compound is evidenced by the values of several conformations, varying within the range of 1 kcal/mol. Theoretical calculations predict chain conformations as the most stable molecular forms, as expected from the presence of the anomeric effect. The experimental fundamental vibrational modes are compared with those obtained theoretically, using ab initio and density functional theory methods, HF/6-31+G and B3LYP/6-31+G, respectively. The density of the compound at ambient temperature (delta = 1.7(1) g/mL), its melting point (mp = -140(5) degrees C), its boiling point (bp = 14.5 (1) degrees C), and the relation between its vapor pressure and the absolute temperature (ln P = 13.699 - 2023.4/T) were also determined.     

Reactions of perfluoro(2,3-epoxy-2-methylpentane) with o-phenylenediamine and ethylenediamine

Perfluoro(2,3-epoxy-2-methylpentane) reacted with o-phenylenediamine and ethylenediamine via cleavage of the C-C bond to produce 2,2,3,3,3-pentafluoro-N-[2-(2,2,2-trifluoro-1-trifluoromethylethylamino)-phenyl]propanamide and 2,2,3,3,3-pentafluoro-N-[2-(2,2,2-trifluoro-1-trifluoromethylethylamino)ethyl]-propanamide, respectively. Presumably, these compounds are formed as a result of rearrangement of intermediate ketone generated by intramolecular haloform-type reaction. According to the NMR and X-ray diffraction data, 2,2,3,3,3-pentafluoro-N-[2-(2,2,2-trifluoro-1-trifluoromethylethylamino)phenyl]propanamide in crystal exists as Z conformer with respect to the amide C-N bond.     

Synthesis of perfluoro(polyether) difunctional compounds

Omega-iodoperfluoro(polyether) esters IR_fOR_fCO₂R have been synthesized by two procedures. These iodoesters have been reacted via zinc coupling reactions to yield alpha, omega-perfluoro(polyether) diesters. The diesters serve as convenient starting materials for the synthesis of a variety of other difunctional compounds of high molecular weight and exhibiting a variation of oxygen-carbon ratio.     

Fluorination of thiocarbonyl compounds with Bis(2-methoxyethyl)aminosulfur trifluoride (Deoxo-fluor reagent): A facile synthesis of gem-difluorides

A variety of thiocarbonyl derivatives (thioketone, thioester, thioamide, dithioester, and dithiocarbamate) were converted to the corresponding gem-difluorides in excellent yields on reaction with the fluorinating agent, bis(2-methoxyethyl)aminosulfur trifluoride, in the presence of SbCl(3).     

EPR study of radiolysis of perfluoro(isobutyl-p-methylcyclohexane)

Conclusions Radiation of perfluoro(isobutyl-p-methylcyclohexane) results in the formation of at least three types of perfluorocarbon radicals that have long lives in the liquid. The extremely low probability of their recombination in the liquid at room temperature may be due to steric shielding of the unpaired electron. The lifetime of the LRs that are formed depends on the radiation dose and temperature.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1260–1263, June, 1988.The authors wish to express their appreciation to K. N. Makarov for assistance in this work.     

Formation of long-lived radicals in radiolysis of perfluoro(4-methyl-2-pentene)

Conclusions On the basis of the EPR spectrum of perfluoro(4-methyl-2-pentene) (PMP) that has been exposed to gamma radiation at 77–300 K, three types of long-lived radicals have been observed, with lifetimes greater than two years. With increases in the radiolysis temperature for radiation dose, the concentration of long-lived radicals increases. Their relative concentrations depend on the irradiation conditions and the thawing schedule.Under certain conditions, long-lived radicals of a single type can be obtained from the PMP.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1263–1268, June, 1988.     

One-pot reaction of ortho-acylphenols and terminal alkynoates for synthesis of 2-alkyl-substituted chromanones

A facile synthesis of 2-alkyl-substituted chromanones from ortho-acylphenols and terminal alkynoates is described. The method contains two consecutive processes in one-pot reaction through a DABCO-catalyzed condensation reaction and a KOBu^t-mediated intramolecular cycloaddition to afford the desired products.     

The synthesis of E-(2s, 3s)-3-trimethylsilylglycidol and its conversion to (−)-propranolol

(?)-Propranolol was synthesized in a highly enantio- and regioselective manner by using titanium mediated asymmetric epoxidation via the key intermediate, E-(2S,3S)-3-trimethylsilylglycidol.     

Isocamphanone in synthesis of 3-alkyl- and 6-alkyl-substituted camphor derivatives

On the interaction of isocamphanone with butyllithium, 2-butyl-5,5,6-trimethylbicyclo[2.2.1]heptan-endo-2-ol is formed stereospecifically. As a result of skeletal rearrangements of carbonium ions taking place in the course of the reaction, the Ritter reaction of this tertiary alcohol with acetonitrile and benzonitrile has given endo-3-butyl-1,7,7-trimethylbicyclo[2.2.1]hept-exo-2-ylacylamines and endo-6-butyl-1,7,7-trimethylbicyclo[2.2.1]hept-2-ylacylamines.Institute of Physical Organic Chemistry, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 807–812, November–December, 1988.     

Microwave-assisted synthesis and micellization behavior of soy-based copoly(2-oxazoline)s

Polymers based on renewable resources are promising candidates for replacing common organic polymers, and thus, for reducing oil consumption. In this contribution we report the microwave-assisted synthesis of block and statistical copolymers from 2-ethyl-2-oxazoline and 2-“soy alkyl”-2-oxazoline via a cationic ring-opening polymerization mechanism. The synthesized copolymers were characterized by gel permeation chromatography and ¹H-NMR spectroscopy. The micellization of these amphiphilic copolymers was investigated by dynamic light scattering and atomic force microscopy to examine the effect of hydrophobic block length and monomer distribution on the resulting micellar characteristics.     

Diastereoselective synthesis and coordination chemistry of enantiopure keto-bis-(2-phosphametallocene)s

Enantiopure 2-(chlorocarbonyl)phosphametallocenes [MCp*(2-{COCl}-3,4-Me(2)-5-Ph-PC(4))] (M = Fe, Ru) react with phospholide anions to give 2-phosphametallocene-2'-acylphospholides K[MCp*(2-CO-2'-{3',4'-Me(2)-5'-PhPC(4)}-3,4-Me(2)-5-Ph-PC(4))] (M = Fe, Ru) and these have been converted into keto-bis-(2-phosphametallocene)s through reaction with [FeClCp*(tmeda)]; templation of this process with CuBr gives rise to the C(2)- (or pseudo-C(2)- when M = Ru) symmetric form of [{MCp*(3,4-Me(2)-5-Ph-PC(4))}(2)-2,2'-(CO)] (M = Fe, Ru; Fe, Fe) with high (>95%) diastereoselectivity. X-Ray structures of these ligands coordinated to [RuCp*Cl] and [PtCl(2)] centres show that the spatial orientation of the very flexible keto-bis-(2-phosphametallocene) structure is highly responsive to the coordination sphere of the chelated platinum or ruthenium centre.     

Isocamphanone in synthesis of 3-alkyl- and 6-alkyl-substituted camphor derivatives

On the interaction of isocamphanone with butyllithium, 2-butyl-5,5,6-trimethylbicyclo[2.2.1]heptan-endo-2-ol is formed stereospecifically. As a result of skeletal rearrangements of carbonium ions taking place in the course of the reaction, the Ritter reaction of this tertiary alcohol with acetonitrile and benzonitrile has given endo-3-butyl-1,7,7-trimethylbicyclo[2.2.1]hept-exo-2-ylacylamines and endo-6-butyl-1,7,7-trimethylbicyclo[2.2.1]hept-2-ylacylamines. Institute of Physical Organic Chemistry, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 807–812, November–December, 1988.