Calix arenes derivatives

Scheme 3.2 shows per-functionalized pillar[5]arene derivatives prepared from per-hydro)ylated pillar[5]arene 3.6 as a starting compound. Applying an efficient organic reaction is required for the perfect introduction of functional groups at all 10 reaction sites. A straightforward and efficient functionalization process for per-hydroxylated pillar[5]arene is etherification, which has been used for functionalization of the lower rims of phenolic moieties in calix[ ]arene derivatives. Various functionalized pillar[5]arene derivatives can be obtained by etherification of per-hydroxylated pillar[5]-arene with an alkyl-halide in the presence of appropriate bases, such as NaH and K2CO3. Introduction of the substituents can change various physical... 

Recently, Kennedy and co-workers [37] have reported the synthesis of well-defined star polymers having well-defined arms of PIB emanating fi-om a calix-arene derivative initiator. Calixarene derivative initiators in conjunction with... 

As in the case of the tetrameric macrocycles discussed above, compounds 17 and 18 can be considered as porphyrinogen analogues or as heteroatom-bridged heteroaromatic calix[4]arene derivatives. The two different conformations observed for 17 and 18 have analogues in compounds 16 (Fig, 5) [15, 28-30],... 

As neutral carriers for the chemical modification, 16-crown-5 and calix[4]arene derivatives possessing a triethoxysilyl group (7) and (8) were designed for Na sensors. Triethoxysilylethyl-16-crown-5(7) was then mixed with a silicone-rubber precursor for the membrane fabrication accompanying covalent bonding of the neutral carrier. Comparison of IR spectra before and after extraction of the nonbonded neutral carrier... 

The coordination chemistry of tertiary phosphine-functionalized calix[4]arenes have been described.279 Treatment of a bis(diphenylphosphino) or bis(dimethylphosphino) derivative of calix[4]arene with [PtCl2(COD)] leads to the formation of the corresponding dichloroplatinum(II) complex. The related diplatinum(II) species has also been reported with the tetrafunctionalized calix[4]arene.280 The mononuclear derivative is susceptible to oligomerization if the two free phosphine ligands are not oxidized or complexed to another metal center such as gold(I).279 The platinum(II) coordination chemistry of a mono-281 and diphosphite282 derived calix[ ]arene (n = 4 and 6, respectively) has also been described. 

Other [AuCIL] complexes with monophosphines are those derived of o-carborane (427),2506 pyr-anoside group (428),2507 a-dimethylamino(3)ferrocenophan-2-yl,2508 calix[4]arene derived phosphites,25 or aminoxyl radical-substituted phosphines (429),2510 for which ferromagnetic interactions have been observed. 

Calixarene crown-6 compounds, which are neutral extractants like crown ethers, are able to coextract technetium with cesium. Tests carried out with several calix-arene-crown ethers (MC7, MC8, MC14, BC2, BC5, BC8, and BC10) show that the extraction of technetium, present in the aqueous phase at a concentration 10 5 M, is enhanced as the cesium concentration in the aqueous phase increases from 10 5 to 10-2 M. As expected, an increase of nitrate concentration prevents pertechnetate extraction in competition with nitrate anion. The extraction of technetium is only appreciable when the nitric acid does not exceed 1 M. Distribution ratios DCs (close to 8) are comparable for the various calixarenes. However, a decrease of extraction is observed for naphtho derivatives.88 89... 

Fig. 13 1 Propanolol amide derivative of S-p-allylcalix[4]arene 2 S-2-dinaphthylprolinol calix[4]arene derivative, a Stern-Volmer plots for the quenching of 1 by S-phenylalaninol and S-phenylglycinol in percent b Stern-Volmer plots for the quenching of 2 by S-phen-ylalaninol and S-phenylglycinol in percent [33]...

Semeril, D., Lejeune, M., Matt, D., Calix [4] arene-derived nickel diphosphine complexes for LLDPE synthesis via orthogonal tandem and one-pot catalysis. NewJ Chem. 2007, 31, 502-505. 

Taking into account om calix[4]tube ligand design10, the novel bis-calix[4]diquinone receptors were prepared via the initial synthesis of various bis-calix[4]arene derivatives connected by alkylene chain units and subsequent oxidation of the remaining phenolic... 

The corresponding dependence of cation complex stability on the anion differs profoundly from that of most other cation receptors such as cyclophanes or calix-arenes [16]. For these cation complex stability decreases on changing the anion from picrate through iodide to tosylate, a dependence that has been attributed to ion-pair aggregation in non-polar solvents. Because the interaction of quaternary ammonium ions with tosylate or iodide in chloroform is considerably stronger than with picrate, cation complexes in the presence of the latter anion are usually more stable. Only when iodide or tosylate cooperatively contributes to cation binding, as in 3 or in some recently described calixarene derivatives [17], is reversal of this order observed. 

Lalor R et al (2008) Cellular uptake of a fluorescent calix[4]arene derivative. J Am Chem Soc 130 2892-2893... 

Structurally somewhat related to recorcin[4]arene derivatives 30a-c is the calix [4]pyrrole derivative 31 described by the Ballester group [74]. 

Scheme 6. In spite of being good host molecules, there is only one well-documented [61] catalytic system based upon the calixarenes. The acid-catalyzed addition of water to yV-benzyl-l,4-dihydronicotinamide 22 to give 24 via 23 is accelerated by the calix[6]arene derivative 25...

Hosseini and co-workers [49] described the synthesis of an infinite single strand helical supramolecular network 27 4 by mixing equimolar amounts of the calix[4]-arene derivative 27, bearing four pyridine groups as H-bond acceptors, with... 

Scheme 11 Preparation of the 1 1 1 complex 27 4, between the calix[4]arene derivative 27. 4,4 -biphenol (4), and MeNC>2.

Figure 6 X-ray structures of calix[4]arene derivatives 1 (a), 3 (b), 4 (c), 5 (d) 7 (e) and 8 (f) adopting the cone conformation and 9 (g) adopting the 1,3-alternate conformation in the crystalline phase For the sake of clarity, solvent molecules and hydrogen atoms are not represented.

The calix[6]arene-derived cholesteryl hexaester 8 was prepared only to inhibit the rotation of the oxygen functions through the annulus.27 Thus, the coalescence observed by NMR for the Ar-CH2-Ar protons at higher temperature (a broad singlet is observed at 130 °C, while a pair of doublets and a singlet at 30 °C are in agreement with a 1,2,3-altemate conformation), indicates the possibility that the p-substituents rotate through the annulus. 

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