New chiral oxo-bridged calix[2]arene[2]triazine for the enantiomeric recognition of α-racemic carboxylic acids

Design, synthesis and application of chiral tetraoxacalix[2]arene[2]triazine‐based organocatalysts in asymmetric Michael addition reactions

“…19,20 The common examples include chiral pyrrolidine-type diamines, 21,22 chiral guanidines, 23,24 L-proline derivatives, 25,26 chiral diamines, 27,28 Cinchona-based catalysts, 29,30 urea and thiourea-derived bifunctional organocatalysts. [36][37][38][39][40][41][42][43][44] We have previously described the synthesis and application of lower rim-substituted calix [4]arene derivatives bearing various functionalities as multiple H-bond donor chiral catalysts in stereoselective transformations. These cavity-shaped macrocycles consist of para-substituted phenolic units connected to each other by methylene bridges at 2,6-positions and are excellent platforms for the preparation of artificial host molecules with various functionalities.…”

Effective asymmetric Michael addition of anthrone to nitroalkenes using chiral tetraoxacalix[2]arene[2]triazines as organocatalysts

“…Tetraoxacalix[2]arene[2]triazines, also known as heteroatom‐bridged calixaromatics, are cavity‐shaped molecules similar to the calix(n)arenes, crown ethers, and cyclophanes. They behave like host molecules and form host‐guest interactions with numerous guest compounds containing various functionality and represent a new important class macrocycles in supramolecular chemistry . The form of the bridging heteroatoms, namely, cooperation of the steric, conjugative, and electronic features for the atoms of nitrogen and oxygen, manages cavity dimensions greatly, which generates a group of precisely set cavities where the distance between two benzene rings at the upper rim varies between 5.011 and 7.979 Å.…”

“…They behave like host molecules and form host-guest interactions with numerous guest compounds containing various functionality and represent a new important class macrocycles in supramolecular chemistry. [3][4][5][6][7] The form of the bridging heteroatoms, namely, cooperation of the steric, conjugative, and electronic features for the atoms of nitrogen and oxygen, manages cavity dimensions greatly, which generates a group of precisely set cavities where the distance between two benzene rings at the upper rim varies between 5.011 and 7.979 Å. The easiness of planning and more advanced chemical modification and the promptly adjustable cavity constructs make such azaand/or oxo-bridged calix [2]arene [2]triazines unmatched fields for studying supramolecular chemistry.…”

Enantioselective recognition of carboxylic acids by novel fluorescent triazine‐based thiazoles

“…To date, many analytical methods such as nuclear magnetic resonance (NMR), circular dichroism (CD), high‐performance liquid chromatography (HPLC), UV/vis, and fluorescence spectroscopy have been developed for chiral molecules determination. Besides all these, molecular recognition measurements are made by analyzing the change in fluorescence properties.…”

“…1 Nowadays, chiral recognition is still attracting considerable research attention in biological, pharmaceutical, forensic, food analysis, and agrochemical fields. [2][3][4] To date, many analytical methods such as nuclear magnetic resonance (NMR), [5][6][7] circular dichroism (CD), 8 high-performance liquid chromatography (HPLC), 9 UV/ vis, 10,11 and fluorescence spectroscopy [12][13][14][15][16][17] have been developed for chiral molecules determination. Besides all these, molecular recognition measurements are made by analyzing the change in fluorescence properties.…”