Water-Soluble Receptors for Cyclic-AMP and Their Use for Evaluating Phosphate-Guanidinium Interactions

Kato, Yōkō; Conn, M. Morgan; Rebek, Julius

doi:10.1021/ja00087a013

Cited by 100 publications

(60 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, hydrophobic effects contribute most of the affinity of related imide receptors for adenine in water (11,12) and overwhelm the hydrogen-bonding component. Titrations of 9-ethyladenine with the receptors were done at five different temperatures from 3-27°C at pH 6 (cacodylate buffer) and ionic strength of 51 mM (NaCI), monitoring the imide proton shift as described (11). Van (1995) carbonyljamino)carbazole (8).…”

mentioning

confidence: 97%

“…The peptide-binding vancomycins have likewise been used (5,6) and have recently yielded additional insights concerning the contributions of entropic effects (7). Water-soluble receptors for nucleic acid components have given a measure of ionic interactions (8)(9)(10)(11) and now permit a direct assessment of hydrogen bonding in water. We report here our preliminary results in that context.…”

mentioning

confidence: 99%

“…A soluble carbazole mono(imide) derivative 1 and bis(imide) 2 were prepared for comparison with the naphthyl mono(imide) 3 and bis(imide) 4 (Scheme 2). The synthesis follows welltrodden paths (11,12) (Fig. 1).…”

mentioning

confidence: 99%

“…The arrangement of imides in receptor 2 is known to chelate adenines in organic solvents through simultaneous Watson-Crick and Hoogsteen base-pairing modes with high binding affinities (Ka > 105 M-1), dominated by hydrogen bonding (13). In contrast, hydrophobic effects contribute most of the affinity of related imide receptors for adenine in water (11,12) and overwhelm the hydrogen-bonding component. Titrations of 9-ethyladenine with the receptors were done at five different temperatures from 3-27°C at pH 6 (cacodylate buffer) and ionic strength of 51 mM (NaCI), monitoring the imide proton shift as described (11).…”

mentioning

confidence: 99%

“…Solvent was removed in vacuo. The waxy solid was dissolved in MeOH (1 ml) and precipitated by addition of ether (5 ml (11). Acid 10b (388 mg, 0.291 mmol) was dissolved in THF (8.8 ml).…”

mentioning

confidence: 99%

See 4 more Smart Citations

Hydrogen bonding in water using synthetic receptors.

Kato

Conn

Rebek

1995

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Four water-soluble adenine receptors were synthesized to study the influence of hydrophobic interactions and hydrogen bonding on molecular recognition in aqueous solution. Association constants were measured in aqueous solution at five temperatures from 3-27°C (pH 6, 51 mM ionic strength). For the mono(imide) receptors, AH was -5.8 kcal/mol (carbazole) and -9.2 kcal/mol (naphthalene). The entropy of association for these was -13 cal mol-l K-1 (carbazole) and -26 cal mol-l K-1 (naphthalene). The carbazole bis(imide) receptor showed a binding enthalpy of -7.4 kcal/mol and entropy of -18 cal mol-l K-1. From this the free energy at 298 K of a single hydrogen bond is estimated to be only 0.2 kcal/mol. The enthalpy of a single hydrogen bond in this solvent-exposed system is estimated to be, at most, 0.8 kcal/mol, indicating that enthalpy just compensates for the unfavorable entropy in this system. These values reflect stronger hydrophobic interactions with the more polarizable naphthalene, as well as enthalpy-entropy compensation effects.

show abstract

mentioning

confidence: 97%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

“…Solvent was removed in vacuo. The waxy solid was dissolved in MeOH (1 ml) and precipitated by addition of ether (5 ml (11). Acid 10b (388 mg, 0.291 mmol) was dissolved in THF (8.8 ml).…”

mentioning

confidence: 99%

See 3 more Smart Citations

Hydrogen bonding in water using synthetic receptors.

Kato

Conn

Rebek

1995

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

Tetrakis(phenylamidinium)-Substituted Resorcin[4]arene Receptors for the Complexation of Dicarboxylates and Phosphates in Protic Solvents

Sebo¹,

Diederich²,

Gramlich

2000

HCA

View full text Add to dashboard Cite

Three bowl‐type cavitand receptors (1 – 3), consisting of a resorcin[4]arene core with four convergent phenylamidinium groups, were prepared in gram quantities by efficient synthetic routes (Schemes 1 and 2) for the recognition of organic anions in CD3OD and D2O. The key steps in the syntheses are the Suzuki cross‐coupling reactions between the tetraiodo cavitands 12, 13, and 23, respectively, with the m‐cyanophenylboronic ester 14 and subsequent conversion of the nitrile to amidinium groups by the Garigipati reaction. Compounds 1 and 2 displayed limited solubility in protic solvents, and evidence for stoichiometric host‐guest association between 2 and AMP (28) could only be obtained by FAB‐MS analysis of a complex precipitated from MeOH (Fig. 2). In contrast, receptor 3 with four triethyleneglycol monomethyl ether side chains was readily soluble in the protic environments, and complexation of isophthalates and nucleotides 25 – 37 was extensively studied by 1H‐NMR titrations and Job's method of continuous variation. In CD3OD and pure D2O, isophthalates 25 and 26 formed stable 1 : 2 host‐guest complexes (Table 1 and Fig. 3), whereas upon addition of borate (pH 9.2) or Tris/HCl buffer (pH 8.3) to the D2O solution, the tendency for higher‐order complexation vanishes. Stable 1 : 1 complexes formed in the buffered solutions (Fig. 4) with 5‐methoxyisophthalate being selectively bound over the 5‐NO2 derivative. Complexation‐induced upfield shifts of specific isophthalate 1H‐NMR resonances (Fig. 5) suggest a preferred inclusion of the methoxyphenyl ring into the receptor cavity. Cavitand 3 forms stable 1 : 1 host‐guest complexes with nucleotides in Tris/HCl‐buffered D2O. Association constants increase strongly with increasing guest charge in the series cAMP

show abstract

Copper‐Catalyzed Amination of Aryl and Alkenyl Electrophiles

2014

View full text Add to dashboard Cite

The copper‐catalyzed arylation and vinylation of nitrogen nucleophiles is a highly versatile method for the construction of sp 2 C–N bonds. Copper‐catalyzed C–N bond formation has an extensive history and the field has been reinvigorated with the development of ligand‐promoted catalyst systems that provide general and effective reactions under relatively mild conditions. Copper promotes arylation and vinylation of a wide range of nitrogen nucleophiles, including amines, nitrogen heterocycles, and amide derivatives. The reactivity profile is complementary to that of palladium and often offers orthogonal chemoselectivity. This chapter presents a thorough overview of the copper‐catalyzed coupling of aryl and vinyl halides with nitrogen nucleophiles. Current understanding of the mechanism of this process is presented along with a detailed overview of the scope and limitations of this reaction along with optimal reaction conditions for the coupling of various nitrogen nucleophile classes.

show abstract

Water-Soluble Receptors for Cyclic-AMP and Their Use for Evaluating Phosphate-Guanidinium Interactions

Cited by 100 publications

References 1 publication

Hydrogen bonding in water using synthetic receptors.

Hydrogen bonding in water using synthetic receptors.

Tetrakis(phenylamidinium)-Substituted Resorcin[4]arene Receptors for the Complexation of Dicarboxylates and Phosphates in Protic Solvents

Copper‐Catalyzed Amination of Aryl and Alkenyl Electrophiles

Contact Info

Product

Resources

About