Reduction of diarylphthalides with aluminum lithium hydride

Conclusions The reduction of diarylphthalides with LiA1H₄ in THF leads to the corresponding diarylphthalans.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, p. 686, March, 1979.     

Non-solvated aluminum hydride. Crystallization from diethyl ether-benzene solutions

Crystallization of non-solvated aluminum hydride from a diethyl ether-benzene mixed solvent was studied. The desolvation of AlH₃·(Et₂O)_x etherate in solution and the crystallization of α-AlH₃ during polythermal heating of the solution occur only in the presence of ≥10 wt.% LiAlH₄. The process is multistage, and the crystallization begins with the formation of the AlH₃·0.25Et₂O solvate, which recrystallizes in the solid phase into γ-AlH₃ and then α-AlH₃. Four crystalline modifications of aluminum hydride were characterized by X-ray diffraction and electron microscopy. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1259–1265, July, 2007.     

Metalation of 1-R-2-benzyl-o-carboranes with lithium aluminum hydride

Carboranes with the general formula I-R-2-PhCH₂-1,2-C₂B₁₀H₁₀ (R = Me, Prⁱ, Ph, PhCH₂) are readily metalated with lithium aluminum hydride in a THF solution at the CH₂ group. In this case only one hydrogen atom in LiAlH₄ is substituted, and trihydride complexes 1-R-2-PhCH(AlH₃Li)-1,2-C₂B₁₀H₁₀, are formed, which are stable in a solutionTranslated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1282–1284, May, 1996.     

Hydroalumination of terminal β-acetylene alcohols with lithium aluminum hydride

Hydrogenation of terminal β-acetylene alcohols with lithium aluminum hydride in THF has afforded homoallylic alcohols. Decomposition of the intermediate organoaluminum complex with deuterated water, iodine, or pyridinium dibromide has evidenced about the non-regioselective hydride attack at the triple bond.     

Reactions of 2,3-diferrocenylcyclopropenone with methyllithium and phenyllithium

Reactions of 2,3-diferrocenylcyclopropenone with methyllithium and phenyllithium afford products of the nucleophilic opening of the three-membered ring, viz., α,β-unsaturated ketones (cis-3,4-diferrocenylbut-3-en-2-one and cis-2,3-diferrocenyl-1-phenylprop-2-enone) and allylic alcohols (cis-3,4-diferrocenyl-2-methylbut-3-en-2-ol and cis-1,1-diphenyl-2,3-diferrocenylprop-2-en-1-ol). The insertion product of a methyl(diferrocenyl)vinylcarbenoid into a σ-bond of the starting compound, viz., 2,3,4-triferrocenyl-4-(1-ferrocenyl-2-oxopropyl)cyclobutenone, along with intramolecular ortho-alkylation products, viz., 2,3-diferrocenylindanone and 2,3-diferrocenyl-2-hydroxyindanone, were also isolated. X-ray diffraction data for triferrocenylcyclobutenone and 2,3-diferrocenyl-2-hydroxyindanone are presented.     

Reduction of unsaturated adamantyl-containing nitriles with lithium aluminum hydride in 2-methyltetrahydrofuran

Reduction of unsaturated adamantyl-containing nitriles with lithium aluminum hydride in 2-methyltetrahydrofuran was examined. It was found that under the synthesis conditions a simultaneous reduction of the double bond and the nitrile group successfully occurred. The presence of bulky substituents in the α-position to the adamantyl moiety of nitriles led to a significant increase in the synthesis duration. A satisfactory yield of the target compounds was achieved only by increasing the temperature and using a two-fold excess of lithium aluminum hydride.     

Reaction of l-aryl-δ2-pyrazoline salts with lithium aluminum hydride

The corresponding pyrazolidines were obtained by reduction of 1-aryl(1-hetaryl)pyrazoline salts. The structure of the products and the reaction mechanism are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 547–550, April, 1973.     

Methyl group exchange in methyllithiumlithium bromide solutions in diethyl ether

The 220 MHz ¹H NMR spectrum of an ether solution of CH₃Li and LiBr in 10–1 ratio has been examined as a function of temperature. At low temperature distinct resonances, assignable to Li₄(CH₃)₄ and Li₄(CH₃)₃Br, are seen. Methyl group exchange between the two tetramers is observed in the NMR spectra in the temperature interval ?32 to 0°. The exchange is shown to be much slower than the dissociation of Li₄(CH₃)₄ tetramer, measured in other work. It is proposed that the rate-determining step is dissociation of Li₄(CH₃)₃Br to form Li₂(CH₃)₂ and Li₂(CH₃)Br. The rate constant for dissociation, k₂, obeys the equation ln k₂ = 36.0?83303/T.