129648-68-6Relevant academic research and scientific papers
Transition-state stabilization and molecular recognition: Acceleration of phosphoryl-transfer reactions by an artificial receptor
Tecilla, Paolo,Chang, Suk-Kyu,Hamilton, Andrew D.
, p. 9586 - 9590 (1990)
An artificial receptor that is complementary to the proposed trigonal-bipyramidal intermediate for phosphoryl-transfer reactions has been designed. Kinetic measurements with 31P NMR methods show that the receptor causes up to a 10-fold acceleration in the aminolysis of phosphorodiamidic chloride derivatives, proceeding via an associative mechanism.
Versatile and practical chiral shift reagent with hydrogen-bond donor/acceptor sites in a macrocyclic cavity
Ema, Tadashi,Tanida, Daisuke,Sakai, Takashi
, p. 3773 - 3775 (2006)
Bifunctional macrocycle 1 with C2 symmetry was newly synthesized. NMR studies demonstrated that receptor 1 functions as a chiral shift reagent (solvating agent) that is highly effective for a wide range of chiral compounds having a carboxylic a
Determination of binding constants of hydrogen-bonded complexes by ITC, NMR CIS, and NMR diffusion experiments
Dethlefs, Christiane,Eckelmann, Jens,Kobarg, Hauke,Weyrich, Thomas,Brammer, Stefan,Naether, Christian,Luening, Ulrich
, p. 2066 - 2074 (2011/05/16)
The host-guest complex formation between barbital and various acylaminopyridyl isophthalamides (Hamilton receptors) has been determined quantitatively. The syntheses of nine isophthalamides are described. Their structures differ in the substitution patter
Versatile and practical macrocyclic reagent with multiple hydrogen-bonding sites for chiral discrimination in NMR
Ema, Tadashi,Tanida, Daisuke,Sakai, Takashi
, p. 10591 - 10596 (2008/02/13)
Bifunctional macrocycles 1-4 and diamide 5 were designed and synthesized. NMR studies demonstrated that, among them, receptor 1 functions as the best chiral solvating agent (shift reagent), which is effective for a wide range of chiral compounds having a carboxylic acid, oxazolidinone, carbonate, lactone, alcohol, sulfoxide, sulfoximine, sulfinamide, isocyanate, or epoxide functionality. The addition of only 5 mol % (69 μg, 0.15 mM) of 1 splits the enantiomeric signals of sulfoxide 13. The excellent performance of 1 as a chiral solvating agent, such as versatility, signal sharpness, high splitting ability, high sensitivity, wide detection window, and synthetic accessibility, is reported. NMR studies revealed that the principal binding site of 1 is the two amide NH groups of the lower segment and that the additional binding site is the pyridyl nitrogen. The V-shaped arrangement of the two 2,6-diacylaminopyridine moieties as constructed in 1 was found to be much more effective for binding a variety of compounds than the parallel alignment of the two binding motifs as constructed in 4. The NO2 group in 1 enhanced not only the binding ability but also the degree of enantioselectivity. Unexpectedly, the comparisons between 1 and 3 enabled us to find the importance of the relative orientation of the binaphthyl moiety; the orthogonal disposition of the binaphthyl moiety in 1 most effectively brings about the differential ring-current effect on the chiral guest molecule bound, which leads to the high degree of chiral discrimination in NMR.
