Intermolecular Interactions of 3,5-Di-tert-butyl-4-hydroxybenzyl Acetate in Crystal and in Solutions

The molecular and crystal structure of 3,5-di-tert-butyl-4-hydroxybenzyl acetate was studied by single-crystal X-ray diffraction. The molecules form infinite chains in the crystals via hydrogen bonds between the hydroxy and carbonyl groups. The interchain bonding is provided by CH- interactions. In carbon tetrachloride, the molecules of the title compound form weak associates via hydrogen bonds between the hydroxy and carbonyl groups.     

Click reaction in the synthesis of novel thiophosphorylated ligands for electrochemical hydrogen evolution

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Synthesis of hydrazones containing sterically hindered phenol groups and tetrathiacalix[4]arene fragment

1,3-Alternate and cone stereoisomers of tetrathiacalix[4]arene and 4-tert-butyltetrathiacalix[4]arene functionalized by carbohydrazide groups reacted with 3,5-di-tert-butyl-4-hydroxybenzaldehyde to give the corresponding hydrazones having sterically hindered phenol fragments.     

Synthesis of 1,3-bis[(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)(dimethoxyphosphoryl)methyl]-4,6-dimethoxybenzene

A reaction of 1,3-dimethoxybenzene with dimethyl (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidenemethyl)phosphonate gave rise to 1,3-bis[(3,5-di-tert-butyl-4-hydroxyphenyl)-(dimethoxyphosphoryl)methyl]-4,6-dimethoxybenzene, which was oxidized to 1,3-bis[(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)(dimethoxyphosphoryl)methyl]-4,6-dimethoxy-benzene.     

New bifunctional compounds obtained by selective hydrolysis of tetrathiacalix[4]arene tetraethyl esters with Cs2CO3

A new strategy for the synthesis of bifunctional compounds, based on 1,3-alternate tetrathiacalix[4]arene precursors functionalized by pairs of carboxylic acid and ester groups located on opposite sides of the macrocycle platform is described. These building blocks were prepared by the Cs₂CO₃ induced selective hydrolysis of tetrathiacalix[4]arene tetraester derivatives. A mechanism for the selective hydrolysis is suggested. The structures of the compounds are elucidated by NMR spectroscopic analysis and X-ray single crystal diffraction.     

Tautomerism of aza cycles: II. Synthesis and structure of 5-substituted 3-(2-hydroxyethylsulfanyl)-1<Emphasis Type="Italic">H</Emphasis>-1,2,4-triazoles and their salts. Preference of the 1H,4<Emphasis Type="Italic">H</Emphasis>-1,2,4-triazolium tautomers

New complexing agents, potentially tautomeric 3-(2-hydroxyethylsulfanyl)-1H-1,2,4-triazole, its 5-methyl-and 5-phenyl-substituted analogs, and some their salts, were synthesized, and their structure was discussed on the basis of the ¹H and ¹³C NMR, IR, and mass spectra, X-ray diffraction data, and published data. In keeping with the rule formulated previously for N-unsubstituted 1,2,4-triazoles having dissimilar substituents, the synthesized compounds were found to exist as 3-(2-hydroxyethylsulfanyl)-5-R-1H-1,2,4-triazole tautomers (3-R_A-5-R_D-1H-1,2,4-triazoly). They are protonated at the nitrogen atom in position 4 of the triazole ring. The ¹H and ¹³C NMR spectra of these compounds in trifluoroacetic acid suggest the presence of two forms due to equilibrium between the neutral and protonated species. Analysis of the crystallographic data for the triazolium salts and published data showed preference of the 1H,4H-1,2,4-triazolium tautomer.     

Synthesis of New Calix[4]arenes Functionalizated by Acetylhydrazide Groups

A series of new calix[4]phenols, calix[4]resorcinols and calix[4]pyrogallols with acetylhydrazide substitutes has been␣synthesized with high yields by hydrazinolysis of ester group containing calix[4]arenes. The synthesized calix[4]phenols adopt the cone conformation while the calix[4]resorcinol and calix[4]pyrogallol derivatives prefer the boat conformation. The amide fragment of the hydrazide groups predominantly exists in the trans-conformation. The binding ability of synthesized calix[4]arenes toward transition and alkali metals by solvent extraction has been investigated.     

Receptor properties of calix[4]resorcinarenes toward tetramethylammonium and choline cations in micellar solutions of sodium dodecyl sulfate

Concentration range of solubilization of calix[4]resorcinarene (H₈L) in sodium dodecyl sulfate (SDS) micelles was found. The interaction of the deprotonated form of H8L (tetraanions [H₄L]⁴⁻) with tetramethylammonium (TMA) and choline cations in micellar solutions of SDS was studied by pH-metry and NMR spectroscopy. The concentration dependences of the change in the cloud point in a multicomponent system TMA (choline)-[H₄L]⁴-SDS-tetrabutylammonium bromide were determined. A correlation of these dependences with host-guest binding processes was found. The sharp change in the cloud points of the corresponding micellar solutions in concentration regions of TMA (0-5·10⁻⁴ mol L⁻¹) and choline (0–1.1· 10⁻³ mol L⁻¹) is caused by the formation of inclusion complexes TMA (choline)-[H₄L]⁴⁻ at the interface of the aqueous and micellar pseudophases. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1366–1371, August, 2006.     

Synthesis and structure of new 2-aryl-substituted pyrrolidines containing phosphine oxide group

2-Aryl-substituted pyrrolidines containing phosphine oxide group have been obtained by the reaction of P-(4,4-diethoxybutylaminomethyl)- P,P-di-p-tolylphosphine oxide with polyatomic phenols.     

Synthesis of novel phosphorus-containing sterically hindered phenols by the reaction of diphenyl (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methylphosphonate with phenols

Diphenyl (3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate was oxidized to the corresponding methylidenequinonoid derivative. The addition of phenols to the exocyclic double bond of this compound gave phosphonates with two phenol moieties.