Showing papers on "Tetrahydrofuran published in 1969"
105 citations
TL;DR: Octamethyl methanetetraboronate, [(MeO) 2 B] 4 C, has been prepared in > 100 g batches by the reaction of dimethoxyboron chloride and carbon tetrachloride with lithium in tetrahydrofuran as discussed by the authors.
65 citations
TL;DR: In this article, the preparation of PhHgCClnBr3−n in good yield can be accomplished by the reaction of phenylmercuric chloride, the respective haloform and the tertbutanol monosolvate of commercial, unsolvated potassium tert-butoxide in ca. 1/1/1.4 molar ratio in tetrahydrofuran solution at -25°.
61 citations
57 citations
TL;DR: The reactions of several dihalides of manganese, iron, cobalt, nickel, copper, and cadmium with tetrahydrofuran and 1,2-dimethoxyethane have been investigated as mentioned in this paper.
49 citations
TL;DR: Poly(2,6-dimethyl-1,4-phenylene ether) (I) was metalated with butyllithium in tetrahydrofuran and with the N,N, N′,N′-tetramethylethylenediamine complex of butyllityium in a variety of solvents as discussed by the authors.
Abstract: Poly(2,6-dimethyl-1,4-phenylene ether) (I) was metalated with butyllithium in tetrahydrofuran and with the N,N,N′,N′-tetramethylethylenediamine complex of butyllithium in a variety of solvents. In these cases, metalation occurred at both the ring and side chain positions, the former being preferred initially. Subsequently, there was an isomerization in favor of the side chain.
At 25°C, there is no significant amount of polymer scission or crosslinking during metalation, but some crosslinking occurs on derivatizing with dimethyl sulfate and trimethylchlorosilane for high extents of ring metalation. With sodium and potassium alkyls, only side-chain metalation was observed. The metalated polymer reacts as a typical organometallic, allowing polymer modification by a wide variety of reactions.
48 citations
TL;DR: The relative reactivities of a ketone, an olefin, and an enol acetate towards bromination in tetrahydrofuran by "pyrrolidone-bromine complex", pyrrolide)3•HBr3 (PHT) are acetate as discussed by the authors.
Abstract: The relative reactivities of a ketone, an olefin, and an enol acetate towards bromination in tetrahydrofuran by "pyrrolidone–bromine complex", (pyrrolidone)3•HBr3 (PHT), are acetate. The conversion...
43 citations
39 citations
36 citations
33 citations
TL;DR: Magnesiacyclohexane, the first example of a magnesisycloalkane, has been prepared from the corresponding mercury derivative as discussed by the authors, and it has been shown that it is present in a monomer/dimer equilibrium, with K-(28.25°) = 531±81 l/mole and K(48.50°) ≈ 223±41 l /mole.
TL;DR: In this paper, nine new organopolygermanes have been prepared, including four lower members of the homologous series of α,ω-diphenylpolymethylpolygermenes of the formula Ph(Me 2 Ge) n Ph, where n = 2−5.
TL;DR: In this article, the proton and lithium-7 nuclear magnetic resonance spectra of tetrahydrofuran (THF) solutions of methyllithium with dimethylmagnesium, dimethylzinc, and dimethylcadmium have been obtained over a wide temperature range.
TL;DR: In this paper, 1,3-propane and 1,4-butane sultone with n-butyllithium in tetrahydrofuran at −78° has been shown to result in metallation α to the sulfonyl group.
Abstract: Treatment of 1,3-propane and 1,4-butane sultone with n-butyllithium in tetrahydrofuran at −78° has been shown to result in metallation α to the sulfonyl group. This is in contrast to ring opening which has been observed when the reaction was carried out at room temperature (1,2). The products obtained from the interaction of the lithio derivatives 3 and 4 with carbonyl compounds and alkyl halides are described.
TL;DR: In this paper, the main dimer of isoprene was oligomerized to a mixture of trimers and higher oligomers, and the maximum yield of this dimer was achieved when the molar ratio of diethylaluminum chloride to hafnium(IV) n-butoxide was 4.7.
Abstract: Oligomerization of isoprene by the catalyst system consisting of hafnium(IV) n-butoxide and diethylaluminum chloride was studied. Isoprene was oligomerized to a mixture of dimers, trimers and higher oligomers. The compound, 2,6-dimethyl-1-trans-3,6-octatriene, was the main dimer of isoprene in this reaction. The maximum yield of this dimer in the reaction at 130°C for 2 hr was accomplished when the molar ratio of diethylaluminum chloride to hafnium(IV) n-butoxide was 4.7. The addition of tetrahydrofuran or triphenylphosphine kept the selectivity for the dimer nearly constant. These results were compared with those obtained by the catalyst system consisting of titanium (IV) n-butoxide or zirconium(IV) n-butoxide and diethylaluminum chloride.
TL;DR: In this article, an investigation has been made on the coordination of Mn2+, Cu2+, and Zn2+, by several simple carboxylic acids and certain of α-oxy-and α-thiocarboxyly acids which have biochemical significance.
TL;DR: In this paper, a comparison between the Arrhenius plots for eleven different propagation rate constants for the anionic polymerization of α-methylstyrene was made in terms of propagation by contact ion-pairs and the more reactive solvent-separated ion-pair.
TL;DR: The absorption spectra of living anionic oligomers of α-methylstyrene with lithium, sodium and potassium counterions have been recorded at temperatures down to −100° in tetrahydrofuran (THF) and −50° in triethylamine triphosphate (THP) as discussed by the authors.
Patent•
20 Mar 1969
TL;DR: SODIUM BOROHYDRIDE in TetraHYDROFURAN can be PREPARED without HANDLING the GAS by TREATINGS as discussed by the authors.
Abstract: SOLUTIONS OF DIBORANE IN TETRAHYDROFURAN CAN BE PREPARED WITHOUT HANDLING THE GAS BY TREATINGSUSPENSIONS OF SODIUM BOROHYDRIDE IN TETRAHYDROFURAN WITH BORON TRIFLUORIDE, FOLLOWED BY DECANTING, FILTERING, OR CENTRIFUGING ITATED SODIUM FLUOBORATE. SUCH SOLUTIONS ARE NORMALLY UNSTABLE AT ORDINARY TEMPERATURES, UNDERGOING REDUCTIVE CLEAVAGE OF THE SOLVENT. CONSEQUENTLY, THEY CANNOT BE STORED FOR ANY APPRECIABLE TIME OF SHIPPED ANY APPRECIABLE DISTANCE. HOWEVER, THESE SOLUTIONS ARE STABILIZED TOWARD SUCH REDUCTIVE CLEAVAGE BY BY UTILIZING IN THE SYNTHESIS A SLIGHT EXCESS OF SODIUM BOROHYDRIDE OR OTHER IONIC BOROHYDRIDES. THESE DICOVERIES NOW MAKE PRACTICAL THE MANUFACTURE, SHIPPING, STORING AND APLICATION OF SUCH SOLUTIONS OF DIBORANE IN TETRAHYDROFURAN, HIGHLY USEFUL FOR HYDROBORATIONS AND HYDROGENATIONS.
TL;DR: The stoicheiometric solvates NaB10H13,2·5dioxan and Na2B 10H12,2thf, and the unsolvated salt (Me4NB 10H13) have been isolated and characterized as mentioned in this paper.
Abstract: The stoicheiometric solvates NaB10H13,2·5dioxan and Na2B10H12,2thf, and the unsolvated salt (Me4N)2B10H12 have been isolated and characterized. The synthetic use of the [B10H13]– ion depends critically on both the cocation and the solvent. Me4NB10H13 reacts with HgCl2 in tetrahydrofuran (thf) to give (Me3N)2[Hg(B10H12)2] and with py2CoX2 in thf to give the novel complexes Me4N[py CoX2B10H11 py] where X = Cl or Br. The [Et3NH]+ salts of these cobalt complexes have also been prepared and characterized by spectroscopic, magnetic, and conductimetric techniques. The cobalt(II) atom is considered to occupy one boron position in the pentagonal face of a B11 cage and is essentially five-co-ordinate with respect to bonding if the [B10H11py]– moiety is considered as a bidentate ligand analogous to [B10H12]2–.
01 Jun 1969
TL;DR: In this paper, the preparation and properties of trans-PtPtPy2[Co(CO)4]2 and trans- PtPy2Y2]2+ + 2 Co(Co)−4 are described.
TL;DR: In this paper, the ReX4L2 and ReOX3L2 complexes of the type ReX 4L2 have been prepared and far-i.m. and H n.r. measurements were used to assign the stereochemistry.
Abstract: Complexes of the type ReX4L2 and ReOX3L2(X = Cl or Br; L = tetrahydrofuran, 1,4-dioxan, 1,4-thioxan and 1,4-dithian) have been prepared. Far-i.r. and H n.m.r. measurements were used to assign the stereochemistry, and in the case of the 1,4-thioxan complexes, sulphur-to-rhenium bonding has been established.
TL;DR: In this article, the reduction of medicagol methyl ether with lithium aluminum hydride in tetrahydrofuran yielded a diol and the dehydration of the diol in boiling diethylene glycol gave an ether (anhydropisatin, O-methyl anhydrosophorol).
Abstract: The reduction of medicagol methyl ether with lithium aluminum hydride in tetrahydrofuran yielded a diol. The dehydration of the diol in boiling diethylene glycol gave an ether (anhydropisatin, O-methyl anhydrosophorol). Then, the above ether was hydrogenated with 10% Pd-C to (±)-pterocarpin.
TL;DR: In this article, a graft copolymer was formed by forming a derivative with trimethylchlorosilane and examining by NMR, it was possible to establish the proportion of lithium scavenged by impurities, the amount of polymeric lithium which reacted with styrene, and the amount which did not.
Abstract: Styrene has been grafted onto poly(2,6-dimethyl-1,4-phenylene ether) (I) with the use of lithiated I as an initiator. In benzene solution, solvent metalation resulted in some polystyrene homopolymer. In tetrahydrofuran, however, only graft copolymer was formed. By forming a derivative with trimethylchlorosilane and examining by NMR, it was possible to establish the proportion of lithium scavenged by impurities, the amount of polymeric lithium which reacted with styrene, and the amount which did not. The chain length of the grafted polystyrene was also calculated. No crosslinking was found, except where a high ratio of lithium to styrene resulted in some unreacted ring-metalated polymer. In this case only, reaction with trimethylchlorosilane causes some crosslinking.
Patent•
27 Aug 1969
TL;DR: In this article, a method of preparing lithium sulfide which comprises forming a reaction mixture of lithium metal and an anhydrous, organic solvent, especially an ether such as tetrahydrofuran, was described.
Abstract: A method of preparing lithium sulfide which comprises forming a reaction mixture of lithium metal and an anhydrous, organic solvent, especially an ether such as tetrahydrofuran capable of dissolving small amounts of lithium metal, heating the reaction mixture to reflux temperature, and introducing hydrogen sulfide into the mixture to form lithium sulfide.
Patent•
Esso1
TL;DR: A ZIEGLER-type CATALyst system for POLYMERIZING ALPHA OLEFINS and CONJUGATED DIENES is described in this article.
Abstract: A ZIEGLER-TYPE CATALYST SYSTEM FOR POLYMERIZING ALPHA OLEFINS AND CONJUGATED DIENES COMPRISING (A) A HYDROCARBON SOLUBLE ADDUCT OF A TITANIUM SUBHALIDE AND A LEWIS BASE, SUCH AS THE METHYL- AND DIMETHYL-DERIVATIVES OF TETRAHYDROFURAN AND TETRAHYDROTHIOPHENE AND (B) AN ORGANO ALUMINUM COMPOUND, SUCH AS DIETHYLALUMINUM CHLORIDE.
TL;DR: In this article, triphenylplumbyllithium was shown to couple readily with reactive halides, but sometimes an exchange reaction is observed, and the tendency to exchange increases in the order: Ph3PbNa.