Naphthalene in tetrahydrofuran

Some alkali metal complexes are also capable of initiating anionic polymerisation. For example, sodium and naphthalene in tetrahydrofuran is a homogeneous solution initiates polymerisation as follows ... 

Cleavage of the sulfonyl esters to the parent alcohols is accomplished in yields of 60-100% by treatment of the p-toluenesulfonates with 2-6 equivalents of sodium naphthalene in tetrahydrofuran at room temperature (yields 60-100%). Sodium naphthalene is prepared by stirring sodium with an equivalent amount or a slight excess of naphthalene in tetrahydrofuran for 1 hour at room temperature under an inert gas [701]. Benzenesulfonates and bromo-benzenesulfonates are also cleaved to the parent alcohols while alkyl methanesulfonates are reduced also to hydrocarbons [701]. 

Reductive removal of fluorine from alkyl fluorides requires a potent reducing agent and so is not normally encountered However, hydrogenolysis of an unactivated carbon-fluorine bond in, for example, 3 p-fluorocholestane has been efficiently accomplished in 88% yield with a solution of potassium and dicyclohexyl 18 crown-6 in toluene at 25 °C [/] Similarly, sodium naphthalene in tetrahydrofuran converts 6 fluorohexene-1 and 1-fluorohexane to hydrocarbons in 50% yield at 25 °C over a 7-h period [2]... 

The reagent alkali metal/naphthalene in tetrahydrofuran reacts with graphite, polynuclear aromatics, and various coals to form chemically reduced products. In the present paper, we emphasize the use of electron paramagnetic resonance data, in the form of g values, linewidths, radical densities, and saturation characteristics, to analyze the reduced coal products and to infer certain differences between the reduced coals and the anions of graphite and simple aromatic hydrocarbons. Additionally, because the interaction of coals with alkali metal/naph-thalene requires much time for completion, we have investigated internal decomposition pathways for the... 

The crown ether-catalyzed generation of the Co( CO)4 ion in ether or hydrocarbon solvents has been described (32). Treatment of the anion with 2,3-bis(bromomethyl)naphthalene in tetrahydrofuran gives what is formulated as a bis-7r-allyl complex, while ketones were isolated using monocyclic dibromides as substrates. 

Preliminary Experiments. Initial work centered on the study of the reaction of potassium with tetrahydrofuran and with naphthalene in tetrahydrofuran. 

The rates of reduction of tetrahydrofuran (Curve A), naphthalene in tetrahydrofuran (Curve B), and a mixture of naphthalene and Illinois No. 6 coal in tetrahydrofuran (Curve C) are shown in Figure 1. These preliminary experiments established that potassium reacted only very slowly with tetrahydrofuran under the experimental conditions used for the formation of the coal polyanion. Naphthalene was rapidly converted to a mixture of anion radicals and dianions under the same conditions. The initial reaction between the electron transfer reagent and the Illinois No. 6 coal was quite rapid. However, the reaction slowed to nearly constant rate after about 12 hr. During the last 4 days of reaction the coal molecules acquired about 0.1 negative charge per 100 carbon atoms per hour. 

Figure 1. The rates of reduction of tetrahydrofuran (A), naphthalene in tetrahydrofuran (B), and Illinois No. 6 coal and naphthalene in tetra-hydrojuran (C) are presented by a comparison of the titer required for aliquots of the reaction mixtures.

The results presented in Figure 1, Curve C, reveal that Illinois No. 6 coal undergoes an initial, very rapid reduction reaction. There is no initial, rapid reaction when the insoluble alkylation products are treated with potassium and naphthalene in tetrahydrofuran in a second alkylation reaction. The observations suggest that accessible acidic hydrogen atoms and other very readily reduced functional groups, e.g., quinoid... 

As already mentioned, several investigators have pointed out that naphthalene or tetrahydrofuran may be incorporated into the coal product (9, 10, 11), In this work we found that chromatographic procedures could be used to separate unbound naphthalene and its reductive alkylation products from the coal alkylation products. The spectroscopic work indicates that the principal resonances of naphthalene and tetrahydrofuran are absent from the butylated coals. Moreover, the mass balance shows that no important quantity of naphthalene or tetrahydrofuran could be incorporated. We supplemented this negative evidence by a comparison of the reaction products obtained from the same coal in a reaction in liquid ammonia. In the most pertinent case the Illinois No. 6 coal was treated with potassium in liquid ammonia. The polyanion was alkylated with butyl iodide. The product distribution obtained by GPC and the spectroscopic properties of these fractions were very closely related to the properties of the reaction products obtained in the reaction with naphthalene in tetrahydrofuran. Recently Larsen and his group found that neither " C-labeled naphthalene nor tetrahydrofuran was incorporated in chemically significant amounts in the coal products separated from the reaction mixture by chromatography (12). 

Following the method first reported for the preparation of triphenyltin sodium using Na naphthalenes trimethyltin potassium is prepared by the action of trimethyltin chloride on potassium naphthalene in tetrahydrofuran (THF), 1,2-dimethoxyethane (DME), or THF-tetraglyme mixture ... 

The anion-radical in tetrahydrofurane is described as an almost ideal reagent for the reductive cleavage of a tosylate to the alcohol. The reagent is prepared by stirring clean pieces of sodium with a slight excess of naphthalene in tetrahydrofurane under nitrogen or argon at room temperature. 

Styrene was added to a solution of sodium naphthalene in tetrahydrofuran at 25°C so that the initial concentrations of styrene and sodium naphthalene in the reaction mixture were 0.2 mol/L and 0.001 mol/L, respectively. Five seconds after the addition of styrene its concentration was determined to be 1.73x10 mol/L. Calculate ... 

In the presence of lithium naphthalene in tetrahydrofuran, isoprene is dimerised to linear monoterpene homologues, and oxidation of the mixture by passage of oxygen gives 30—40% of Cio alcohols and 30% of C,o glycols. Of the mono-hydric alcohols, 10% nerol and 10% geraniol are obtained in addition to 5% of... 

Dibenzylamine added to a soln. of Li-naphthalene in tetrahydrofuran, then n-hexyl bromide added N-hexyldibenzylamine. Y 90%. F. e. s. K. Suga et al., Chem. Ind. 1969, 78. 

Figure 18-6. Variation of the triad tacticity with molar mass, that is, with the monomer/ initiator ratio, in the polymerization of a-methyl styrene with sodium naphthalene in tetrahydrofuran at 78° C. (From data of H.-G. Elias and V. S. Kamat.)...

Solutions of sodium naphthalene in tetrahydrofuran are dark green, electrically conducting because the compound consists of ions Na(THF)/ and... 

The most difficult-to-bond plastics family is polytetrafluoroethylene and the other fluori-nated polymers which are the Teflon-like materials. The widespread use of these polymers as coatings for cookware is, of course, based on this property of nonsticking. The conventional methods of etching which can be useful with other difificult-to-bond plastics, like polyethylene and polypropylene, simply do not work on these fluorinated polymer surfaces. Instead the surfaces must be treated with an exotic mixture of metallic sodium and naphthalene in tetrahydrofuran.( 37,i38) More recently, ionized gases (plasma treatment) have also been used successfully. Once treated the surfaces become bondable using conventional two-part liquid... 

Diethylamine added at -30° to a soln. of Li-naphthalene prepared from Li and naphthalene in tetrahydrofuran, then crotonic acid in tetrahydrofuran added drop-wise at - 5° followed by cyclohexanone, and heated 1.5 hrs. at 60° y-(l-hydroxy-... 

Figure 6 EPR spectrum of the radical anion of naphthalene in tetrahydrofuran as solvent. The radical was formed by dissolving naphthalene in sodium-dried tetrahydrofuran under vacuum and passing the resultant solution over a sodium metal film, again under vacuum conditions. The number of lines is given by 2nl+ I where / equals the nuclear spin and n the number of nuclei. HFCC for 1,4,5,8 = 0.483 mT and for 2,3,6,7 = 0.185 mT.

Solutions of sodium-naphthalene in tetrahydrofuran are dark green, electrically conducting because the compound is a salt Na (THF) CioHs", and paramagnetic because of the extra electron which is in a singly occupied 7r-orbital. Information about the distribution of the unpaired electron about its various possible positions in the anion can in suitable cases be derived from the electron spin resonance spectrum. If the orbital occupied by the unpaired electron in a hydrocarbon anion is non-degenerate, as is the case with naphthalene and anthracene, then a second electron (formation of anion ) would enter the same orbital and both the paramagnetism and e.s.r. spectra disappear. 

Sodium naphthalide will initiate the polymerization of styrene in an inert solvent such as tetrahydrofuran. This was one of the first living polymer systems studied. The initiator is made first of all by adding sodium to a solution of naphthalene in tetrahydrofuran. 

Ytterbium dicyclopendienide was prepared by reducing dicyclopentadienyl ytterbium chloride with finely dispersed sodium metal in tetrahydrofurane (Calderazzo et al., 1966). Samarium(II) dicyclopentadienide was isolated as the 1-tetra-hydrofuranate. This compound was prepared by reaction between SmfCsHj), and potassium naphthalene in tetrahydrofurane (Watt et al., 1969). It is insoluble in this solvent and very air-sensitive. Desolvation of the compound at elevated temperature under reduced pressure is accompanied by decomposition. 

Acetylene passed slowly into a soln. of Li-naphthalene in tetrahydrofuran to give Li-acetylide quantitatively, then j -ionone added ethynyl-/ -ionol. Y 90%. - This is a convenient procedure for the ethynylation of a,y -unsatd. ketones under very mild conditions. F. e. s. K. Suga, S. Watanabe, and K. Takahashi, Chem. Ind. 1967, 1748 Can. J. Chem. 46, 3041 (1968) 2-acetylene-1,4-diols s. Chem. Ind. 1968, 1489. 

---