The Hydrogen Bond. I. Intra- and Intermolecular Hydrogen Bonds in Alcohols<sup>1</sup>

Kuhn, Lester P.

doi:10.1021/ja01130a013

Cited by 457 publications

(101 citation statements)

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“…Intermolecular hydrogen bonding is not expected to occur at concentrations below 0.5 molar (14). If an NH group is present in the molecule, N-H stretching vibrations interfere since they give rise to a broad absorption between 3000 and 3500 cm-I, thus overlapping with the absorption due to the OH vibrations.…”

Section: Nhacmentioning

confidence: 99%

Differential reactivity of carbohydrate hydroxyls in glycosylations. II. The likely role of intramolecular hydrogen bonding on glycosylation reactions. Galactosylation of nucleoside 5′-hydroxyls for the syntheses of novel potential anticancer agents

Whitfield¹,

Douglas²,

Tang³

et al. 1994

Can. J. Chem.

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Contrary to expectations, many primary hydroxy groups are completely unreactive in glycosylation reactions, or give the desired glycosides in very low yields accompanied by products of many side reactions. Hydrogens of such primary hydroxyls are shown to be intramolecularly hydrogen bonded. Intermediates formed by nucleophilic attack by these hydroxyls on activated glycosylating agents may resist hydrogen abstraction. This resistance to proton loss is postulated to be the origin of the observed unreactivity. It is shown that successful glycosylations take place under acidic conditions under which such hydrogen bonds cease to exist. Accordingly, direct galactosylations of the normally unreactive 5'-hydroxyls of nucleosides were accomplished for the first time with a galactose trichloroacetimidate donor in chloroform under silver triflate promotion. It is noted that such galactosylated anticancer nucleosides may have improved biological specificity. Contrairement a ce que l'on peut privoir, plusieurs groupes hydroxyles primaires ne rtagissent pas du tout au cours des reactions de glycosylation ou avec seulement de faibles rendements accompagnCs de plusieurs sous-produits. On a dCmontrC que les hydrogknes de ces hydroxyles primaires sont impliquks dans des liaisons hydrogbnes. Les intermkdiaires qui se forment par attaque nuclCophile de ces hydroxyles sur des agents activCs de glycosylation peuvent rCsister a la reaction d'enlkvement de l'hydrogkne. ~e t t e r~sistance B la perte d'un proton se produit en milieu acide alors que de telles liaisons hydrogbnes cessent d'exister. On a rCalisC pour la premikre fois des galactosylations directes des hydroxyles normalement non rCactifs en 5' des nuclCosides en utilisant comme donneur un trichloroacCtimidate de galactose dans le chloroforme sous promotion par le triflate d'argent. I1 a CtC suggCrC que de tels nuclCosides anticanckreux galactosyles pourraient avoir une spCcificitC biologique amClioree.[Traduit par la redaction]

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Section: Nhacmentioning

confidence: 99%

Differential reactivity of carbohydrate hydroxyls in glycosylations. II. The likely role of intramolecular hydrogen bonding on glycosylation reactions. Galactosylation of nucleoside 5′-hydroxyls for the syntheses of novel potential anticancer agents

Whitfield¹,

Douglas²,

Tang³

et al. 1994

Can. J. Chem.

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“…Some works describe this interaction as a weak hydrogen bond on the grounds of geometrical and spectroscopic criteria. [10][11][12] However, according to electron density topological analysis calculations, there is no evidence for the existence of an intramolecular hydrogen bond. 14,16,22,23 Because the aim of the present work is not to discuss whether intramolecular hydrogen bonding is present in vicinal diols, we will adopt the definition of hydrogen bond recommended by IUPAC.…”

Section: Introductionmentioning

confidence: 99%

“…Previous infrared spectroscopic studies of this molecule in a dilute solution of inert solvents, 10,11 vapor phase, 11,12 and matrix isolation 12 have shown the presence of a lower-frequency band in the OH-stretching region in addition to the absorption band due to the free OH (higher-frequency band). This lowerfrequency absorption was assigned to the presence of an intramolecular hydrogen bond between the two hydroxyl groups.…”

Section: Introductionmentioning

confidence: 99%

Conformational Study of Monomeric 2,3-Butanediols by Matrix-Isolation Infrared Spectroscopy and DFT Calculations

et al. 2006

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The FT-IR spectra of two diastereomers of 2,3-butanediol, (R,S) and (S,S), isolated in low-temperature argon and xenon matrixes were studied, allowing the identification of two different conformers for each compound. These conformers were characterized by a (gauche arrangement around the O-C-C-O dihedral angle, thus enabling the establishment of a very weak intramolecular hydrogen bond of the O‚‚‚H-O type. No other forms of these compounds were identified in matrixes, despite the fact that these four conformers had calculated relative energies from 0 to 5.1 kJ mol -1 and were expected to be thermally populated from 50 to 6% in the gaseous phase of each compound. The nonobservation of additional conformers was explained in terms of low barriers to intramolecular rotation, resulting in the conformational relaxation of the compounds during deposition of the matrixes. The barriers to internal rotation of the OH groups were computed to be less than 4 kJ mol -1 and are easily overcome in matrixes within the family of conformers with the same heavy atom backbone. The barriers for intramolecular rearrangement of the O-C-C-O dihedral angle in both diastereomers were calculated to range from 20 to 30 kJ mol -1. Interconversions between the latter conformers were not observed in matrixes, even after annealing up to 65 K. Energy calculations, barriers, and calculated infrared spectra were carried out at the DFT(B3LYP)/6-311++G** theory. Additional MP2/ 6-311++G** calculations of energies and vibrational frequencies were performed on the most relevant conformers. Finally, independent estimations of the hydrogen-bond enthalpy in the studied molecules were also obtained based on theoretical structural data and from vibrational frequencies (using well-established empirical correlations). The obtained values for -∆H for both diastereomers of 2,3-butanediol amount to ca. 6-8 kJ mol -1 .

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“…The spectral shifts of the bonded OH from the free OH are much greater than those in the corresponding OH-to-O bonded systems with similar geometries, [5][6][7][8][9] suggesting that the tertiary aminonitrogen is more basic, or stronger as a proton acceptor, than the hydroxyl-or ether-oxygen.2) In fact, thermodynamical investigations3,10) of the formation of inter-and intra-molecular OH-to-N(tertiary) and OH-to-O bonds have shown that the enthalpies of the former are higher than those of the latter. From this information, and from monomethylethers capable of forming an intramolecular hydrogen bond are confined to those which contain at most four or five carbon atoms by which the terminal, oxygen-containing groups are separated, it was expected that acyclic 5-dialkylaminopentanols might also be internally bonded, forming an eight-membered ring.…”

mentioning

confidence: 99%

Intramolecular Hydrogen Bonds. X. Intramolecular Hydrogen Bonding in ω-N, N-Diethylaminoalkanols

Mōri¹,

Nakamura²,

Tsuzuki³

1967

Bulletin of the Chemical Society of Japan

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The Hydrogen Bond. I. Intra- and Intermolecular Hydrogen Bonds in Alcohols¹

Cited by 457 publications

References 0 publications

Differential reactivity of carbohydrate hydroxyls in glycosylations. II. The likely role of intramolecular hydrogen bonding on glycosylation reactions. Galactosylation of nucleoside 5′-hydroxyls for the syntheses of novel potential anticancer agents

Differential reactivity of carbohydrate hydroxyls in glycosylations. II. The likely role of intramolecular hydrogen bonding on glycosylation reactions. Galactosylation of nucleoside 5′-hydroxyls for the syntheses of novel potential anticancer agents

Conformational Study of Monomeric 2,3-Butanediols by Matrix-Isolation Infrared Spectroscopy and DFT Calculations

Intramolecular Hydrogen Bonds. X. Intramolecular Hydrogen Bonding in ω-N, N-Diethylaminoalkanols

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The Hydrogen Bond. I. Intra- and Intermolecular Hydrogen Bonds in Alcohols1

Cited by 457 publications

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Differential reactivity of carbohydrate hydroxyls in glycosylations. II. The likely role of intramolecular hydrogen bonding on glycosylation reactions. Galactosylation of nucleoside 5′-hydroxyls for the syntheses of novel potential anticancer agents

Differential reactivity of carbohydrate hydroxyls in glycosylations. II. The likely role of intramolecular hydrogen bonding on glycosylation reactions. Galactosylation of nucleoside 5′-hydroxyls for the syntheses of novel potential anticancer agents

Conformational Study of Monomeric 2,3-Butanediols by Matrix-Isolation Infrared Spectroscopy and DFT Calculations

Intramolecular Hydrogen Bonds. X. Intramolecular Hydrogen Bonding in ω-N, N-Diethylaminoalkanols

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The Hydrogen Bond. I. Intra- and Intermolecular Hydrogen Bonds in Alcohols¹