[14]Heterophane prototypes containing azolium and/or azole anion-binding motifs.

Revisiting a '3 + 1' convergent stepwise strategy permitted the synthesis of [14]imidazoliophane 2·2Br in excellent yield for a macrocyclization. The new [14]triazoliophane 3 and bis(1,2,3-triazolium) counterpart 4·2Cl were less synthetically accessible and the hybrid derivative 5·Cl proved troublesome to prepare. Triazolophane 3 was devoid of anion-binding affinities, while charged [14]heterophane prototypes showed a particular preference for acetate. When association constants were compared, dicationic systems 2·2PF6 and 4·2PF6 showed greater values than monocationic macrocycle 5·PF6, and the highest affinities corresponded to the bis(imidazolium) receptor 2·2PF6.

A simple halide-to-anion exchange method for heteroaromatic salts and ionic liquids.

A broad and simple method permitted halide ions in quaternary heteroaromatic and ammonium salts to be exchanged for a variety of anions using an anion exchange resin (A(-) form) in non-aqueous media. The anion loading of the AER (OH(-) form) was examined using two different anion sources, acids or ammonium salts, and changing the polarity of the solvents. The AER (A(-) form) method in organic solvents was then applied to several quaternary heteroaromatic salts and ILs, and the anion exchange proceeded in excellent to quantitative yields, concomitantly removing halide impurities. Relying on the hydrophobicity of the targeted ion pair for the counteranion swap, organic solvents with variable polarity were used, such as CH(3)OH, CH(3)CN and the dipolar nonhydroxylic solvent mixture CH(3)CN:CH(2)Cl(2) (3:7) and the anion exchange was equally successful with both lipophilic cations and anions.

A general halide-to-anion switch for imidazolium-based ionic liquids and oligocationic systems using anion exchange resins (A- form).

Further studies on the application of an AER (A(-) form) method broadened the anion exchange scope of representative ionic liquids and bis(imidazolium) systems. Depending on the hydrophobicity nature of the targeted imidazolium species and counteranions, different organic solvents were used to swap halides for assorted anions, proceeding in excellent to quantitative yields.

Synthetic approaches to multifunctional indenes.

The synthesis of multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such as the [3-(aminoethyl)inden-5-yl)]amines, a reasonable pathway involves the (5-nitro-3-indenyl)acetamides as key intermediates. Although several multistep synthetic approaches can be applied to obtain these advanced intermediates, we describe herein their preparation by an aldol-type reaction between 5-nitroindan-1-ones and the lithium salt of N,N-disubstituted acetamides, followed immediately by dehydration with acid. This classical condensation process, which is neither simple nor trivial despite its apparent directness, permits an efficient entry to a variety of indene-based molecular modules, which could be adapted to a range of functionalized indanones.

Identification of novel indanylsulfonamide guanylhydrazones as potent 5-HT6 serotonin receptor antagonists.

Changing the N,N-(dimethylamino)ethyl side chain in the N-[3-(aminoethyl)inden-5-yl]sulfonamide 5-HT(6) serotonin receptor agonists 1 by a conformationally rigid guanylhydrazone moiety at the indene 3-position led to the identification of the title indanylguanylhydrazones 6, which exhibited excellent binding affinities and an antagonistic response at the 5-HT(6) receptor, with K(i) and IC(50) values in the nanomolar range (K(i) >or= 1.2 nM, IC(50) >or= 47 nM, and I(max)

Bis(imidazolium)-calix[4]arene receptors for anion binding.

Efficient access to the bis(imidazolyl)calixarene 2 and dicationic bis(imidazolium) salts 1a,b x 2X directly bonded to the upper rim of calixarene structure has been reported. Anion binding properties of the new receptors were studied by 1H NMR spectroscopic methods. Bis(N-butylimidazolium) dication 1a exhibited the best recognition properties toward carboxylate anions with a 1:1 receptor-anion binding stoichiometry, whereas the presence of a bulky group such as isopropyl (1b) increased the difficulty of both imidazolium moieties to be able to support the association with the same single anion.