Stereospecificity in the transformation of α-aminoacids into fluoroacids

Faustini, F.; Munari, Sergio De; Panzeri, A.; Villa, V.; Gandolfi, C.

doi:10.1016/s0040-4039(01)93034-5

Cited by 37 publications

(6 citation statements)

References 6 publications

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“…This method is superiort ot he longer route via openingo fa no xirane. [19] The bromofluoro intermediates 23 a [25,26] www.chemmedchem.org ic bromination reactiono fc ommerciallya vailableb enzoxa-zol2(3H)-one (25)w ithb romine was conducted (Scheme 3). [27] As previously reported, [28] the reaction took place with high regioselectivity resulting exclusively in the desired 6-bromobenzoxazolone 26.T he formation of 26 was proved unequivocally by 15 N-GHMBC NMR experiments.B ecauseP d-assisted coupling of aryl bromide 26 with propargyl alcohol did not take place, the benzoxazolone NH moiety was protected by am ethyl or methoxymethyl moiety (MOM).…”

Section: Synthesismentioning

confidence: 53%

“…This method is superior to the longer route via opening of an oxirane . The bromofluoro intermediates 23 a and 23 b were obtained by reaction of the terminal olefins 22 a and 22 b with N ‐bromosuccinimide (NBS) and Et 3 N⋅3 HF. Heating of 23 a and 23 b with NaN 3 led to β‐fluoroazides 24 a and 24 b , which afforded the desired β‐fluoroamines 7 a and 7 b by reduction with H 2 and Pd/C.…”

Section: Resultsmentioning

confidence: 99%

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Replacement of the Benzylpiperidine Moiety with Fluorinated Phenylalkyl Side Chains for the Development of GluN2B Receptor Ligands

et al. 2018

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The 4‐benzylpiperidine moiety is a central structural element of potent N‐methyl‐d‐aspartate (NMDA) receptor antagonists containing the GluN2B subunit. To obtain novel GluN2B ligands suitable for positron emission tomography, the benzylpiperidine moiety was replaced with fluorinated ω‐phenylalkylamino groups. For this purpose three primary propyl‐ and butylamines 7 a–c and one butyraldehyde 7 d bearing a fluorine atom and an ω‐phenyl moiety were prepared in 3‐ to 7‐step syntheses. Compounds 7 a–d were attached to various scaffolds of potent GluN2B antagonists (scaffold hopping) instead of the original 4‐benzylpiperidine moiety. Although benzoxazol‐2‐ones and indoles with a benzylpiperidine moiety show high GluN2B affinity, the corresponding fluorophenylalkylamine derivatives did not result in high Glu2B affinity. Moderate GluN2B affinity was observed for a 3‐(fluoroalkyl)‐substituted tetrahydro‐1H‐3‐benzazepine (Ki=239 nm). However, high GluN2B affinity was obtained for the tetrahydro‐5H‐benzo[7]annulen‐7‐amines 12 a–c (Ki=17–30 nm). Docking studies resulted in the same binding pose for 12 a as for the lead compound Ro 25‐6981. It can be concluded that some GluN2B ligands (benzoxazolones, indoles) do not tolerate replacement of the 4‐benzylpiperidine moiety with flexible fluorinated phenylalkyl side chains, but other scaffolds such as tetrahydro‐3‐benzazepines and ‐benzo[7]annulenes retain interaction with NMDA receptors containing the GluN2B subunit.

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Section: Synthesismentioning

confidence: 53%

Section: Resultsmentioning

confidence: 99%

Replacement of the Benzylpiperidine Moiety with Fluorinated Phenylalkyl Side Chains for the Development of GluN2B Receptor Ligands

et al. 2018

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“…The synthesis of ( S )‐11 and ( R )‐11 is presented in Scheme . L ‐Valine was reacted with HNO 2 between −5 and 0 °C in an aqueous solution to give ( S )‐2‐hydroxy‐3‐methylbutanoic acid with the retention of the original ( S ) configuration because of the anchimeric assistance provided by the carboxylate group 16. A similar mechanism was valid for the replacement of the amino group with chlorine via the diazonium salt intermediate.…”

Section: Resultsmentioning

confidence: 95%

Chiral recognition in molecular and macromolecular pairs of (S)- and (R)-1-cyano-2-methylpropyl-4?- {[4-(8-vinyloxyoctyloxy)benzoyl]oxy}biphenyl-4- carboxylate enantiomers

Percéc

Asandei

Zheng

2000

J. Polym. Sci. A Polym. Chem.

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(S)‐1‐Cyano‐2‐methylpropyl‐4′‐{[4‐(8‐vinyloxyoctyloxy)benzoyl]oxy}biphenyl‐ 4‐carboxylate [(S)‐11] and (R)‐1‐cyano‐2‐methylpropyl‐4′‐{[4‐(8‐vinyloxyoctyloxy)benzoyl]oxy}biphenyl‐4‐carboxylate [(R)‐11] enantiomers, both greater than 99% enantiomeric excess, and their corresponding homopolymers, poly[(S)‐11] and poly[(R)‐11], with well‐defined molecular weights and narrow molecular weight distributions were synthesized and characterized. The mesomorphic behaviors of (S)‐11 and poly[(S)‐11] are identical to those of (R)‐11 and poly[(R)‐11], respectively. Both (S)‐11 and (R)‐11 exhibit enantiotropic SA, S *C, and SX (unidentified smectic) phases. The corresponding homopolymers exhibit SA and S *C phases. The homopolymers with a degree of polymerization (DP) less than 6 also show a crystalline phase, whereas those with a DP greater than 10 exhibit a second SX phase. Phase diagrams were investigated for four different pairs of enantiomers, (S)‐11/(R)‐11, (S)‐11/poly[(R)‐11], and poly[(S)‐11]/poly[(R)‐11], with similar and dissimilar molecular weights. In all cases, the structural units derived from the enantiomeric components are miscible and, therefore, isomorphic in the SA and S *C phases over the entire range of enantiomeric composition. Chiral molecular recognition was observed in the SA and SX phases of the monomers but not in the SA phase of the polymers. In addition, a very unusual chiral molecular recognition effect was detected in the S *C phase of the monomers below their crystallization temperature and in the S *C phase of the polymers below their glass‐transition temperature. In the S *C phase of the monomers above the melting temperature and of the polymers above the glass‐transition temperature, nonideal solution behavior was observed. However, in the SA phase the monomer–polymer and polymer–polymer mixtures behave as an ideal solution. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3631–3655, 2000

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“…(R)-2-Bromopentanedioic Acid Dimethyl Ester (1a). (R)-2-Bromoglutaric acid 29,30 was first prepared by gradually adding a solution of NaNO 2 (55.6 g, 806.0 mmol) in water (300 mL) over a period of 5 h to a mixture of D-glutamic acid (66.0 g, 448.0 mmol) and NaBr (161.3 g, 1.6 mol) in 2 M HBr (400 mL) cooled at −5 °C. About 3 h after the addition of NaNO 2 , concentrated H 2 SO 4 (15 mL) was added.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Design of a New Glutamine–Fipronil Conjugate with α-Amino Acid Function and Its Uptake by A. thaliana Lysine Histidine Transporter 1 (AtLHT1)

Jiang

Xie

Ren

et al. 2018

J. Agric. Food Chem.

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Creating novel pesticides with phloem mobility is essential for controlling insects in vascular tissue and root, and conjugating existing pesticides with amino acid is an effective approach. In order to obtain a highly phloem-mobile candidate for efficient pesticides, an electro-neutral l-glutamine-fipronil conjugate (l-GlnF) retaining α-amino acid function was designed and synthesized to fit the substrate specificity of an amino acid transporter. Cotyledon uptake and phloem loading tests with Ricinus communis have verified that l-GlnF was phloem mobile, and its phloem mobility was higher than that of its enantiomer d-GlnF and other previously reported amino acid-fipronil conjugates. Inhibition experiments then suggested that the uptake of l-GlnF was, at least partially, mediated by an active transport mechanism. This inference was further strengthened by assimilation experiments with Xenopus oocytes and genetically modified Arabidopsis thaliana, which showed a direct correlation between the uptake of l-GlnF and the expression of amino acid transporter AtLHT1. Thus, conjugation with l-Gln appears to be a potential strategy to ensure the uptake of pesticides via an endogenous amino acid transport system.

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Stereospecificity in the transformation of α-aminoacids into fluoroacids

Cited by 37 publications

References 6 publications

Replacement of the Benzylpiperidine Moiety with Fluorinated Phenylalkyl Side Chains for the Development of GluN2B Receptor Ligands

Replacement of the Benzylpiperidine Moiety with Fluorinated Phenylalkyl Side Chains for the Development of GluN2B Receptor Ligands

Chiral recognition in molecular and macromolecular pairs of (S)- and (R)-1-cyano-2-methylpropyl-4?- {[4-(8-vinyloxyoctyloxy)benzoyl]oxy}biphenyl-4- carboxylate enantiomers

Design of a New Glutamine–Fipronil Conjugate with α-Amino Acid Function and Its Uptake by A. thaliana Lysine Histidine Transporter 1 (AtLHT1)

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