Two novel 1,3-calix[4]azacrowns

Proton-diionizable Bis-calix[4]azacrown Ether through Mannich Reaction

“…It is certain that in basic condition the intermolecular or intramolecular hydrogen bond which can be estimated in solution state can be ruled out by deprotonation of the OH. This strongly indicates that the Mg 2+ ion is selectively encapsulated by the calixazacrown not only through the size agreement between the azacrown cavity and Mg 2+ ion but also through cation/π-interaction proposed by Kim [7][8][9][10] and Reinhoudt. 14 Most importantly, the additional coordinative phenoxy anion plays an significant role in the high extractability for Mg 2+ ion.…”

“…6 Recently, we have been intrigued by the synthesis of ditopic receptor that is defined with bis-calixazacrown molecule capable of binding two guest ions in the azacrown cavity. [7][8][9][10] For this system we have also tried to synthesize the methoxymethylated compound on the nitrogen atom of the calixazacrown as a precursor of the Mannich product, but the reaction was not accomplished. Interestingly, we then finally found one-pot synthetic method for 2 and 3 as shown in Scheme 1.…”

Novel calix[4]cryptands: “Mappemonde II” and “Mill II”

“…The glycolic signals of 1 were overlapping while the one of 2 were not. That the calix [4]arenes units were in the 1,3-alternate conformation was shown by the appearance of singlet at 3.89 ppm for 1 and 3.82 ppm for 2 matching the value of 3.88 ppm in 3 [12]. For the mass spectra, one contained a peak at m/z 1025.5 corresponding to calix [4]cryptand mappemonde (1) + H + 2H 2 O and the other one had a peak at m/z 2016.5 indicating calix [4]cryptand mill (2) + K + .…”

“…With reference to these previous works [10,11] we have designed related molecular structures 1 and 2 corresponding to the molecular "mappemondes" and "mill" in which the 1,3-calix [4]bis-crown has been replaced by the already published 1,3-calix [4]bis-(aza)crown 3 [12]. The two nitrogen atoms in the crown loops were used to attach the polyether links.…”

“…Staring materials were used without further purification. 1,3-Calix [4]bis-azacrown (3) [12] and benzoheptaethylene glycol ditosylate (4) [13] were prepared according to the literature procedures. (4) in 20 mL of acetonitrile was added dropwise.…”