Synthesis of 2,5-bis-(Ethynyl) furan Derivatives from 2,5-Furandicarboxaldehyde

A synthesis of the title compounds has been accomplished by conversion of 2,5-furandicarboxaldehyde to the dilithium salt of 2,5-bis-(ethynyl) furan followed by reaction with electrophiles.     

Synthesis of benzoates of 1,4-bis(2,5-dimethyl-4-hydroxypiperidino)-2-butene and 1,4-bis-(2,5-dimethyl-4-hydroxypiperidino)-2-butyne

1,4-Bis(2,5-dimethyl-4-hydroxypiperidino)-2-butene and 1,4-bis(2,5-dimethyl-4-hydroxypiperidino)-2-butyne (II and III) were obtained by the action of 1,4-dibromo-2-butene and 1,4-dibromo-2-butyne on the form of 2,5-dimethyl-4-piperidol (I). The benzoates (IV and V) were obtained by acylation of II and III with benzoyl chloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 352–353, March, 1971.     

2,5-Bis-(butyltelluro) thiophene as a convenient precursor for the synthesis of 2,5-bis-(acetylenic) thiophenes

Both symmetrically and unsymmetrically substituted 2,5-bis-(acetylenic) thiophene derivatives were obtained in good yields under mild conditions through palladium-catalyzed cross coupling reaction of 2,5-bis-(butyltelluro) thiophene 2 and terminal alkynes. The methodology represents a general and efficient protocol for carrying out the synthesis of thiophene derivatives with potential biological activities.     

2-(2,4,6-tri-tert-butylphenyl)-1-phosphaethin, 1,4-bis-(trimethylsiloxy)-1,4-bis-(2,4,6-tri-tert-butylphenyl)-2, 3-diphosphabutadien

The title compounds are prepared for the first time by reaction of 2,4,6-tri-tert-butyl-benzoylchloride and tris-(trimethylsilyl)-phosphane.     

Synthesis and applications of 3,4-dihydroxy-2,5-bis-(2′-(4′-substituted-oxazolinyl)) furan

Three 3,4-dihydroxy-2,5-bis-(2′-(4′-substituted-oxazolinyl)) furans were synthesized at 90%–94% yields from reaction of 3,4-dihydroxyfuran-2,5-dicar-boxylic acid or its dimethyl ester with chiral β-amino alcohol via a one-step process. Their chemical structures were determined by ¹H NMR, IR, MS, and elemental analysis. With these chiral bisoxazoline ligands, the asymmetric reductive reaction of β-acetonaphthalene with KBH₄ or NaBH₄ was preliminarily studied. The enantiomeric excess of the reduction product was up to 83.2% with cyclohexane as the solvent, the molar ratio of ligand: reductive agent: β-acetonaphthalene is 0.04:1.6:1, and 72-hours reaction time at 0°C. Furancontaining bisoxazoline with 4-benzyl on oxazoline rings exhibited higher enatioselectivity than congeneric bisoxazolines with 4-ethyl on oxazoline rings. __________ Translated from Chinese Journal of Applied Chemistry, 2005, 22(12) (in Chinese)     

Unconventional reactivity of epichlorohydrin in the presence of triphenylphosphine: isolation of ((1,4-dioxane-2,5-diyl)-bis-(methylene))-bis-(triphenylphosphonium) chloride

Research on Chemical Intermediates - The selective formation of the heterocyclic salt ((1,4-dioxane-2,5-diyl)-bis-(methylene))-bis-(triphenylphosphonium) chloride was observed when epichlorohydrin...     

Palladium(II) chloride catalyzes the cross-coupling reaction of 2,5-bis-(butyltelluro)-furan and 1-alkynes

Palladium(II) chloride catalyzed the cross-coupling reaction of 2,5-bis-(butyltelluro) furan and terminal alkynes yielding both symmetrically and unsymmetrically substituted 2,5-bis-acetylenic furan derivatives. The methodology represents a general and efficient protocol for carrying out the synthesis of furan derivatives with potential biological activities.     

Crystal structure of 1,2-bis-(phenylseleno)-1,2-dichlorethene

Vladimir State Pedagogical Institute. Institute for Elementorganic Compounds, Russian Academy of Sciences. Irkutsk Institute for Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 4, pp. 153–154, July–August, 1992.     

Absolute configuration and conformational stability of (+)-2,5-dimethylthiolane and (-)-2,5-dimethylsulfolane

Enantiopure (+)-2,5-dimethylthiolane and (-)-2,5-dimethylsulfolane were prepared using literature procedures and investigated using vibrational circular dichroism (VCD). Experimental absorption and VCD spectra of (+)-2,5-dimethylthiolane and (-)-2,5-dimethylsulfolane in CCl(4) solution in the 2000-900 cm(-)(1) region were compared with the ab initio predictions of absorption and VCD spectra obtained with density functional theory using the B3LYP/6-311G(2d, 2p) basis set for different conformers of (2R,5R)-2,5-dimethylthiolane and (2R,5R)-2,5-dimethylsulfolane. This comparison indicates that (+)-2,5-dimethylthiolane is of the (2R,5R)-configuration and has two predominant conformations in CCl(4) solution. In addition, (-)-2,5-dimethylsulfolane is of (2R,5R)-configuration and has only one predominant conformation. The stereochemical assignment is in agreement with literature.     

2,5-Dimethyl-4-(p-alkylbenzyl)pyridines

1,2,5-Trimethyl-4[p-methyl(ethyl, isopropyl) benzyl]-4-piperidole were obtained and converted to the similarly substituted pyridine bases.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1642–1645, December, 1970.     

2,5-Bis(vinyloxyalkylamino)-1,4-benzoquinones

Russian Journal of Organic Chemistry -