Reactivity Control by Calixarenes

Abstract

[No abstract available

Inherently chiralcone-calix[4]arenesviaa subsequent upper rim ring-closing/opening methodology

“…Chromatographic purification (SiO 2 , hexane/ethyl acetate 8 : 2) afforded compound 1 (20 mg, 0.026 mmol, 43% yield, offwhite waxy solid) and unreacted 1 (30 mg). 1 13…”

“…1 H NMR and 13 Electrospray Ionization-Time Of Flight mass spectrometry was performed with an ESI/QTOF mass spectrometer.…”

“…The chromatographic purifications (SiO 2 , hexane/ethyl acetate 10 : 1 → 5 : 1 → 1 : 1) attempted to isolate 3 failed because of identical RF values with precursor 6. However, the spectroscopic characterization ( 1 H NMR, 13 C-NMR, UV-Vis and FT-IR) was still possible because of the low amount of impurity (7%) present (obtained 130 mg of total impure material, 50% crude yield). 1 H NMR (400 MHz, CDCl 3 ) δ: 1.12 (t, J = 8 Hz, 3 H), 1.15 (t, J = 8 Hz, 3 H), 1.23 (t, J = 8 Hz, 3 H), 1.24 (t, J = 8 Hz, 3 H), 3.…”

“…The upper rim functionalization has particularly shown promising applications in the recognition of biologically relevant species, mostly proteins 9,10 and DNA, 11 and as catalytically active systems. [12][13][14][15][16] In order to push the field towards biological systems even further, envisioning new strategies for the preparation of inherently chiral calixarenes [17][18][19][20] is pivotal. Effective procedures for the synthesis of symmetrically tetra-, distally-and proximally-upper rim-substituted calix [4]arenes have been extensively developed; 21 however, to the best of our knowledge, only two examples of inherently chiral ABCH 22 and ABCDupper rim 23 functionalized derivatives have been reported so far by other authors.…”

“…) 13. C NMR (100 MHz, CDCl 3 ) δ:15.37, 15.41, 31.01, 31.08, 31.43, 66.31, 66.41, 66.71, 66.79, 69.54, 69.62, 70.38, 72.41, 72.78, 73.30, 73.95, 74.07, 122.74, 128.36, 129.00, 129.28, 129.83, 130.04, 130.52, 130.82, 131.52, 131.71, 131.89, 133.38, 133.62, 134.33, 134.85, 136.79, 137.29, 137.83, 138.04, 155.57, 158.36, 159.68, 164.76, 172.75, 191.97.…”