A general synthesis of halo-oligopyridines. The Garlanding concept

Voisin‐Chiret, Anne Sophie; Bouillon, Alexandre; Burzicki, Grégory; Célant, Melanie; Legay, Rémi; El‐Kashef, Hussein; Rault, Syl­vain

doi:10.1016/j.tet.2008.11.024

Cited by 38 publications

(35 citation statements)

References 30 publications

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“…As side reaction, the substitution of the second bromine (position 8) in AQ46 was observed to some extent reducing the overall reaction yield. The high reactivity of bromine in the ortho‐position of the pyridine ring (position 6') in AQ46 can also lead to undesired couplings . Therefore, it would be advantageous to design a precursor molecule containing an unreactive group of cross‐coupling at that position.…”

Section: Chemistrymentioning

confidence: 82%

“…The high reactivity of bromine in the ortho-position of the pyridine ring (position 6') in AQ46 can also lead to undesired couplings. 45,46 Therefore, it would be advantageous to design a precursor molecule containing an unreactive group of cross-coupling at that position. Thus, possessing the bromo precursor AQ46, we explored the aromatic bromo-to-fluoro nucleophilic substitution and performed preliminary in vitro characterization of [ 18 F]AQ28A.…”

Section: Organic Synthesis and Radiolabeling Of The Bromo Precursormentioning

confidence: 99%

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Radiosynthesis and biological evaluation of the new PDE10A radioligand [¹⁸F]AQ28A

Wagner

Teodoro

Deuther‐Conrad

et al. 2016

Labelled Comp Radiopharmac

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Cyclic nucleotide phosphodiesterase 10A (PDE10A) regulates the level of the second messengers cAMP and cGMP in particular in brain regions assumed to be associated with neurodegenerative and psychiatric diseases. A better understanding of the pathophysiological role of the expression of PDE10A could be obtained by quantitative imaging of the enzyme by positron emission tomography (PET). Thus, in this study we developed, radiolabeled, and evaluated a new PDE10A radioligand, 8-bromo-1-(6-[ F]fluoropyridin-3-yl)-3,4-dimethylimidazo[1,5-a]quinoxaline ([ F]AQ28A). [ F]AQ28A was radiolabeled by both nucleophilic bromo-to-fluoro or nitro-to-fluoro exchange using K[ F]F-K -carbonate complex with different yields. Using the superior nitro precursor, we developed an automated synthesis on a Tracerlab FX F-N module and obtained [ F]AQ28A with high radiochemical yields (33 ± 6%) and specific activities (96-145 GBq·μmol ) for further evaluation. Initially, we investigated the binding of [ F]AQ28A to the brain of different species by autoradiography and observed the highest density of binding sites in striatum, the brain region with the highest PDE10A expression. Subsequent dynamic PET studies in mice revealed a region-specific accumulation of [ F]AQ28A in this region, which could be blocked by preinjection of the selective PDE10A ligand MP-10. In conclusion, the data suggest [ F]AQ28A is a suitable candidate for imaging of PDE10A in rodent brain by PET.

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Section: Chemistrymentioning

confidence: 82%

Section: Organic Synthesis and Radiolabeling Of The Bromo Precursormentioning

confidence: 99%

Radiosynthesis and biological evaluation of the new PDE10A radioligand [¹⁸F]AQ28A

Wagner

Teodoro

Deuther‐Conrad

et al. 2016

Labelled Comp Radiopharmac

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“…In 2009, Voisin‐Chiret et al 97. investigated the Suzuki–Miyaura reaction of dihalopyridines bearing two different halogen atoms with halopyridylboronic acids bearing a carbon‐halogen bond with lower reactivity than the carbon‐halogen bonds in the dihalopyridines and found that the heteroarylation reaction occurred at the more reactive carbon‐halogen bond of the halopyridine substrates irrespective of its position on the ring.…”

Section: Cross‐coupling Reactions Of Polyhalogenated Six‐membered Hmentioning

confidence: 99%

Selective Palladium‐Catalyzed Suzuki–Miyaura Reactions of Polyhalogenated Heteroarenes

2012

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The palladium-catalyzed Suzuki-Miyaura reaction of multiply halogenated, electron-rich and electron-deficient heteroarenes is one of the most reliable and environmentally friendly tools for installing a wide range of non-functionalized and functionalized carbon substituents onto heteroaromatic systems with exquisite chemo-and site-selectivity. For substrates with different halogen groups the chemoselectivity of the Suzuki-Miyaura reactions has been found to be dependent on the reactivity difference between the halogens. However, the hardest achievement of selectivity in Suzuki-Miyaura monocouplings involving polyhalogenated heteroarenes with identical halogen atoms has been shown to be dominated by steric and electronic effects and the presence of directing groups at positions neighbouring the reaction sites. Moreover, in the case of symmetrically substituted dihaloheteroarenes with identical halogen atoms, highly selective monocoupling reactions have often been achieved only after a careful optimization of reaction parameters including the catalyst precursor, base, solvent, and the molar ratio between electrophile and organoboron reagent. This critical review with 341 references covers developments on the chemo-and site-selective Suzuki-Miyaura monocoupling reactions of polyhalogenated heteroarenes with different or identical halogen atoms. It also includes the synthesis of polysubstituted heteroarenes, not easily accessible by other means, via consecutive monocoupling reactions and/ or a more synthetically valuable approach involving one-pot polycoupling reactions.

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“…The strategy allows the preparation of an infinite number of these new compounds and hence access to a library of halooligopyridines. 9 The PEG-immobilisation and the liquid phase synthesis of some coumarins derived from cardol have been presented. Some preliminary results on their tyrosinase inhibitory activity are also included.…”

Section: Solution-phase Synthesismentioning

confidence: 99%

Combinatorial Chemistry Online Volume 11, Issue 2, February 2009

Terrett

2009

Combinatorial Chemistry - an Online Journal

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A general synthesis of halo-oligopyridines. The Garlanding concept

Cited by 38 publications

References 30 publications

Radiosynthesis and biological evaluation of the new PDE10A radioligand [¹⁸F]AQ28A

Radiosynthesis and biological evaluation of the new PDE10A radioligand [¹⁸F]AQ28A

Selective Palladium‐Catalyzed Suzuki–Miyaura Reactions of Polyhalogenated Heteroarenes

Combinatorial Chemistry Online Volume 11, Issue 2, February 2009

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A general synthesis of halo-oligopyridines. The Garlanding concept

Cited by 38 publications

References 30 publications

Radiosynthesis and biological evaluation of the new PDE10A radioligand [18F]AQ28A

Radiosynthesis and biological evaluation of the new PDE10A radioligand [18F]AQ28A

Selective Palladium‐Catalyzed Suzuki–Miyaura Reactions of Polyhalogenated Heteroarenes

Combinatorial Chemistry Online Volume 11, Issue 2, February 2009

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Product

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Radiosynthesis and biological evaluation of the new PDE10A radioligand [¹⁸F]AQ28A

Radiosynthesis and biological evaluation of the new PDE10A radioligand [¹⁸F]AQ28A