Membrane transport of dicarboxylic and α-hydroxy carboxylic acids induced by α-amino phosphonates

Phosphorylated amino derivatives of thiacalix[4]arene as membrane carriers: synthesis and host–guest molecular recognition of amino, hydroxy and dicarboxylic acids

“…Also, the signals of aromatic protons are observed as four singlets of equal intensity at 6.57, 7.47, 7.52 and 7.59 ppm, although they usually appear as two singlets and an AB‐spin system with a 1:1 intensity. The observed scenario occurs when the thiacalix[4]arene is in a distorted cone conformation where one of the thiacalix[4]arene aromatic rings partially occupies the macrocyclic cavity . Two‐dimensional 1 H– 1 H NMR NOESY spectroscopy also confirms the proposed assumption.…”

“…amine which participates in hydrogen bonding with the hydroxyl and carboxyl groups of guests . Unfortunately, the selectivity of α‐aminophosphonates is commonly not very high . However, the spatial attachment of the binding fragments mentioned in the calixarene platform resulted in development of selective host molecules for tartaric and succinic acids .…”

“…[27][28][29][30][31][32][33] Unfortunately, the selectivity of α-aminophosphonates is commonly not very high. [34,35] However, the spatial attachment of the binding fragments mentioned in the calixarene platform resulted in development of selective host molecules for tartaric and succinic acids. [35] Replacement of the methylene bridge groups of "classical" calix [4]arene with sulfide bridges leads to significant changes in the chemical characteristics of thiacalix [4]arene and its complexing ability.…”

Highly functionalized calix[4]arenesviamulticomponent reactions: synthesis and recognition properties

“…Previously, acyclic a-aminophosphonates such as diethyl(2-(octadecylamino)propan-2-yl)phosphonate a and diethyl((octadecylamino) (phenyl)methyl)phosphonate b were 19598 | RSC Adv., 2019, 9,[19596][19597][19598][19599][19600][19601][19602][19603][19604][19605] This journal is © The Royal Society of Chemistry 2019 successfully used as an efficient and selective carrier to transport some diacids and a-hydroxy acids through a certain liquidimpregnated membrane (Scheme 10). 58 But in this work, the use of p-tert-butylcalix [4]arene as a platform with three-dimensional structure could modify the selectivity through preorganization of binding sites.…”