Synthesis and 1H NMR Complexation Study of Thiacalix[4]arene Tetraacetates

Abstract

Alkylation of thiacalix[4]arenes with ethyl bromoacetate led to high yields (≈60%) of corresponding tetraacetates in various conformations (cone, partial cone, 1,3-alternate) depending strictly on the carbonate (Na, K, Cs) used for the reaction. The complexation ability of new compounds was studied by 1H NMR.

Chemistry of Thiacalixarenes

“…The interactions of thiacalix [4]arenes (bearing acetate or amide groups on the lower rim) with transition metals [88] and alkali metal cations [10,12,89] have also been studied. Although the absolute values of the complexation constants for tetraacetates 14a,b,d and 15a,b,d are much lower that those of the corresponding calix [4]arene derivatives, the selectivities for alkali metals were quite interesting.…”

“…The selectivity of 15a is shifted towards the smaller sodium cation [K(Na ϩ ) ϭ 2900  Ϫ1 ]; K ϩ , Rb ϩ , and Cs ϩ were not complexed at all under the conditions used. [12] The important feature of thiacalixarenes 2 and 4 is their ability to accommodate neutral molecules (i.e. solvent molecules) within their cavities or in the crystal lattice.…”

“…[1] Accordingly, several groups have studied [10,11,12] the alkylation of thiacalixarenes 2 and 13 with ethyl bromoacetate using the acetone/M 2 CO 3 reaction system (M ϭ Li, Na, K, and Cs). This reaction (Scheme 3) exhibits a surprisingly pronounced template effect, and leads to high yields of the corresponding tetraacetates 14 and 15 in various conformations (cone, partial cone, 1,3-alternate conformers from the alkylation reaction of the thiacalixarene 2 with α-bromoacetophenone was studied in detail.…”

Porphyrin-Calix[4]arenes

“…Polar solvents induce more complex exciton interactions [55]. As shown in [63][64][65][66][67], the hydrophobic cavity in thiacalix [4]arene is larger than in calix [4]arene with methylene bridging groups. The distances between two contiguous (cis) and two opposite (trans) sulfur atoms in 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(ethoxycarbonylmethoxy)-2,8,14,20-tetrathiacalix [4]arene (LXII) in the cone conformation are 5.48 and 7.67 Å, respectively, while the distances between the corresponding CH 2 groups in analog LXI are 5.11 and 7.16 Å [63].…”

Thiacalix[4]arene’s Lower Rim Derivatives: Synthesis and Supramolecular Properties

“…Thiacalix [4] 3: R=t-Bu; Y=(СH 2 ) n Br, n=2-5; [21] 4: R=t-Bu; Y=CH 2 C(O)N(Et) 2 ; [19] 5: R=H; Y=CH 2 C(O)N(Et) 2 ; [20] 6: R=t-Bu; Y=CH 2 C(S)N(Et) 2 ; [22] 7: R=t-Bu; Y=CH 2 C(O)Ph; [18] 8: R=H; Y=CH 2 C(O)Ph; [20] 9: R=t-Bu; Y=N-propoxyphtalimide; [23,24] 10: R=t-Bu; Y=(CH 2 ) 3 CN; [25] 11: R=H; Y=(CH 2 ) 3 CN; [26] 12: R=t-Bu; Y=CH 2 C≡CH; [27] 13: R=H; Y=CH 2 C≡CH; [27] 14: R=t-Bu; Y=(CH 2 ) n C≡CH, n=3-6; [28] 15: R=t-Bu; Y=(CH 2 Py(α,β,γ); [29] 16: R=H; Y=(CH 2 Py(α,β,γ); [30] 17: R=t-Bu; Y=(CH 2 ) n -pyrazolyl, n=2-4; [31] 18: R=t-Bu; Y= CH 2 C 6 H 4 CN; [32] 19: R=t-Bu, Y =CH 2 COOEt; [33,34] 20: R=Н, Y=CH 2 COOEt; [35] 21: R=t-Bu, Y=CH 2 COOH; [36] 22: R=t-Bu, Y=CH 2 COCl; [37] 23: R=t-Bu; Y=(СH 2 ) n SH, n=2-5; [21] 24: R=t-Bu; Y=(СH 2 ) n S-terPy, n=2-5; [38] 25: R=t-Bu; Y=(CH 2 ) 3 NH 2 ; [39] 26: NHC(O)NHPh; [39] 27: R=t-Bu; Y=(СH 2 ) 3 NH(NH 2 ) 2 + Cl -; [40] 28: R=t-Bu; Y=(СH 2 ) 3 NHP(O)OEt 2 . bearing two pairs of different substituents on opposite sides of the thiacalix [4]arene scaffold are of great interest for the design very sophisticated and advanced supramolecular architectures.…”