Hydrophosphinoyl derivatives of calix[4]resorcinarenes

Calix[4]resorcinarene reacts with N,N,N",N"-tetraethyl-P-ethylphosphonous diamide to give dioxaphosphocines, whose hydrolysis with intracavity water yields phosphinoyl derivative of calix[4]resorcinarene.     

Microwave-assisted synthesis of calix[4]resorcinarenes

Microwave-assisted synthesis of calix[4]resorcinarenes by cyclocondensation of various aldehydes and resorcinol catalysed by 12-tungstophosphoric acid type Keggin (H₃PW₁₂O₄₀·13H₂O) or concentrated HCl is described. Excellent isolated yields (up to 90%) were attained within short reaction times (typically, 3-5 min) when the reaction was performed under microwaves irradiation.     

Photoresponsive upper-rim azobenzene substituted calix[4]resorcinarenes

Photoswitchable calix[4]resorcinarenes with different numbers of azo groups in the upper rim were synthesised by the reaction of bromomethylcavitand with 4-aminoazobenzene. UV-vis, ¹H and ¹³C NMR, MALDI TOF-MS spectral data have been used to elucidate the structures of compounds.     

Mannich reaction involving calix[4]resorcinarenes and aminoacetals

The Mannich reaction involving calyx[4]resorcinarenes, aminoacetals, and formaldehyde in the molar ratio 1:4:4 yields calixarenes containing aminoacetal fragments on the upper molecule rim. Four oxazinyl rings formed with the retention of acetal groups as the formaldehyde amount was twofold increased.     

Synthesis and Antioxidative Properties of Bis(3,5-di-tert-butyl-4-hydroxyphenyl) Polysulfides

An efficient procedure was developed for preparing bis(3,5-di-tert-butyl-4-hydroxyphenyl) polysulfides in the presence of phenolic Mannich bases. The antioxidative activity of the resulting bis(polysulfides) in rubbers of various structures and in their vulcanizates was examined.     

Single-electron oxidation and nucleophilicity of aminomethylated calix[4]resorcinarenes

The electrochemical oxidation of a number of aminomethylated calix[4]resorcinarenes (AMC) with different substituents at the nitrogen atom and the kinetics of nucleophilic substitution reactions of these compounds with p-nitrophenyl bis(chloromethyl)phosphinate were studied. The reactivity of the ionic associates of AMC in the nucleophilic substitution and the behavior of AMC in electrooxidation are determined by the same factors, namely, the amino-group basicity and the nature of the substituents at the nitrogen atom. These factors influence the ratio of the zwitter-ionic and anionic forms of AMC.     

Synthesis of 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-2-r-benzimidazoles

Reaction of 2,6-di-tert-butyl-1,4-benzoquinone with o-phenylendiamine gives 2,6-di-tert-butyl-1,4-benzoquinone-4-(N-o-aminophenyl)imine which reacts smoothly with heterocyclic, aromatic and aliphatic aldehydes to form (1-(3,5-di-tert-butyl-4-hydroxyphenyl)-2-substituted benzimidazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 483–485, April, 1990.     

Dialkylaminomethylated Calix[4]resorcinarenes. Reaction with Carboxylic Acids

5,11,17,23-Tetrakis(N,N-dimethylaminomethyl)-2,8,14,20-tetranonylcalix[4]resorcinolarene was found to form in solutions host-guest complexes with tartaric, phthalic, and succinic acids; the stability of the complexes depends on the degree of protonation of the host in the complex and the structure of the guest.     

Synthesis of hybrid compounds by benzylation of acylhydrazones with 3,5-di-tert-butyl-4-hydroxybenzyl acetate

Russian Chemical Bulletin - N-Benzylation of acylhydrazones of the hydroxybenzaldehyde series with 3,5-di-tert-butyl-4-hydroxybenzyl acetate was performed at room temperature in the absence of acid...     

Synthesis of calix[4]resorcinarenes with phosphorylaryl substituents at the lower rim of the molecule

Reaction of resorcinarenes with 4-phosphorylbenzaldehydes afforded calix[4]resorcinarenes, bearing phosphorylaryl substituents at the lower rim of the molecule. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2269–2271, November, 2007.     

Functional modification,self-assembly and application of calix[4]resorcinarenes

As a special subset of calix[4]arene, calix[4]resorcinarene is an excellent molecular platform which could be modified by introducing functional groups to multiple sites at the upper and lower rims. There are mainly three ways to build functionalized calix[4]resorcinarene derivatives: (1) modification on the C-2 sites of calix[4]resorcinarenes; (2) modification on the phenolic hydroxyl groups of calix[4]resorcinarenes; (3) modification on the bridging methylenes at lower rim of calix[4]resorcinarenes. Functionalized calix[4]resorcinarene derivatives play an important role in the development of self-assembly chemistry, among which hydrogen bonding and metal coordination are the two most common interactions to obtain multicomponent structures. Moreover, due to the excellent topological structures and various active substituents of functionalized calix[4]resorcinarene derivatives, their applications in various fields, such as nanoparticles, catalysts, fluorescent materials, and sensors, have been briefly presented in this paper.

     

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.     

Synthesis,characterization, and photolysis of poly[3,5-di-tert-butyl-4-[(2,4,6-tri-tert-butylphenyl)oxalato]phenylacetylene], a photochemical polyradical precursor

A photochemical precursor to a pendant conjugated polyradical has been synthesized, poly[3,5-di-tert-butyl-4-[(2,4,6-tri-tert-butylphenyl)oxalato]phenylacetylene], 3 . Irradiation of 3 at 77 K in the solid state at < 300 nm yielded poly(3–5-di-tert-butyl-2-oxyphenyl acetylene), 2 , with 30–40% of the expected number of radical spins. Spin yields on the surface of solid samples appears to be considerably higher. Electron spin resonance experiments showed no evidence of cooperative exchange interaction between the pendant spins. Computational modeling indicated that a major reason for the failure of this and other polyphenylacetylenes to show ferromagnetic exchange between spins is the substantial twisting of the polyacetylene backbone required by steric interactions, leading to deconjugation and a loss of exchange interaction between pendant radicals along the chain. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2167–2176, 1997     

Short synthesis of tert-butyl-hydroxylated 3,5-di-tert-butyl-4-hydroxybenzaldehyde: Synthesis of tert-butyl-hydroxylated S-2474

We have developed a very short synthesis of tert-butyl-hydroxylated di-tert-butyl-4-hydroxybenzaldehyde in which the HBr-DMSO system is used as an effective oxidant (overall yield of 45% for the entire four-step process from 2-tert-butyl-p-cresol). We also accomplished the synthesis of a major metabolite of the antiarthritic drug candidate S-2474.     

Reaction of 2-Ethyl-1,3,2-bezoxaphospholine with Calix[4]resorcinarenes

By reaction of calix[4]resorcinarene with 2-ethyl-1,3,2-benzoxazaphospholine in 1:1 ratio we prepared a cavitand possessing one dioxaphosphocinic fragment on the upper circle of the molecule. Reaction of the same compounds in ether solution in 1:4 and 1:8 ratio according to the data of spectral methods leads initially to formation of addition product, the P-H phosphorane with composition 1:4. This compound is not stable and on keeping forms 2-oxo-2-ethyl-1,3,2-benzoxazaphospholine, spirophosphorane, o-aminophenol and phosphorylated calixarene. In the reaction of the aminoalkylated calixarene with 2-ethyl-1,3,2-benzoxazaphospholine we isolated a compound possessing four hydrophoshonyl fragments on the upper circle of the calixarene matrix.