Gold‐Catalyzed Redox Synthesis of Imidazo[1,2‐<i>a</i>]pyridines using Pyridine <i>N</i>‐Oxide and Alkynes

Talbot, Eric P. A.; Richardson, Melodie; McKenna, Jeffrey M.; Toste, F. Dean

doi:10.1002/adsc.201300996

Cited by 69 publications

(27 citation statements)

References 52 publications

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“…1 H NMR: (DMSO‐ d 6 , 400 MHz): δ 7.40 (1H, t , J = 7.4, Hc); 7.50 (1H, t , J = 7.6, Hb); 7.75 (1H, d , J = 9.8 Hz, H8); 7.96 (1H, dd , J = 9.2, 2.2, H7); 8.00 (2H, d , J = 7.3, Ha); 8.63 (1H, s , H3); 9.84 (1H, t , J = 2.2, H5). Spectroscopic data were in agreement with those reported in the literature . RT: 2.73 min.…”

Section: Methodssupporting

confidence: 90%

Design and Synthesis of Imidazo[1,2‐a]pyridines with Carboxamide Group Substitution and In silico Evaluation of their Interaction with a LuxR‐type Quorum Sensing Receptor

Lara

Salgado-Zamora

Bazin

et al. 2018

Journal of Heterocyclic Chem

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Quorum sensing, an important process of bacterial communication, is involved in the development of complex behavior and expression of virulence factors that become important due to its key role in infection process. In this manuscript, docking studies were used as a preliminary screening to identify main interactions between LuxR receptor (CviR) of Chromobacterium violaceum as model and N‐acyl L‐homoserine lactones. Thus, following this approach, a library of imidazo[1,2‐a]pyridines bearing carboxamide and urea moieties was designed, evaluated on this in silico model previously validated, and synthesized to generate new potential quorum sensing inhibitors. The present article summarizes survey to develop these new molecules with potential biological activity, based on interaction analysis ligand‐receptor.

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Section: Methodssupporting

confidence: 90%

Design and Synthesis of Imidazo[1,2‐a]pyridines with Carboxamide Group Substitution and In silico Evaluation of their Interaction with a LuxR‐type Quorum Sensing Receptor

Lara

Salgado-Zamora

Bazin

et al. 2018

Journal of Heterocyclic Chem

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“…[120][121][122] Some representative examples are shown in Scheme 38. [124] Astrategy to access cyclopropylnaphthalenes from diynes and alkenes is also based on the use of 136 as the catalyst (Scheme 38 C). [123] Complex 136 also catalyzes the formation of imidazole[1-,2-a]pyridines from alkynes and 2-aminopyridine N-oxides (Scheme 38 B).…”

Section: [(N^o)au III ]C Omplexesmentioning

confidence: 99%

“…[123] Complex 136 also catalyzes the formation of imidazole[1-,2-a]pyridines from alkynes and 2-aminopyridine N-oxides (Scheme 38 B). [124] Astrategy to access cyclopropylnaphthalenes from diynes and alkenes is also based on the use of 136 as the catalyst (Scheme 38 C). [125] Very recently,t he…”

Section: [(N^o)au III ]C Omplexesmentioning

confidence: 99%

Cyclometalated Gold(III) Complexes: Synthesis, Reactivity, and Physicochemical Properties

2017

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This Review showcases the ability of bi- and tridentate ligands to stabilize gold in high oxidation states through the formation of mono- and biscyclometalated gold(III) complexes. In-depth studies on the synthesis, intrinsic reactivity, catalytic relevance, and photophysical properties of stabilized gold(III) species have been carried out, setting the stage for exciting developments in various research areas, such as catalysis, inorganic and bioinorganic chemistry, ligand design, and materials science.

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“…[1][2][3][4][5] In particular, some of their derivatives have been used as current clinical treatments and they have good pharmaceutical activity against a range of disease targets. [10][11][12] Gold-catalyzed dipolar cycloadditions have been widely investigated and have proven to be successful in the synthesis of various fused imidazo [1,2-a] heterocycles. Transition metal-catalyzed cycloadditions are among the most powerful and simple methods for the synthesis of imidazo[1,2a] heteroaromatic frameworks from an N-nucleophilic reagent and unsaturated precursors.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of the gold(i)-catalyzed synthesis of imidazo-pyrimidines and imidazo-pyrazines via [3 + 2] dipolar cycloaddition: a DFT study

Zhang

Geng

2016

RSC Adv.

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Density functional theory calculations have been carried out to study the mechanisms of gold(I)-catalyzed [3 + 2] cycloaddition reactions of pyridinium N-(heteroaryl)-aminides, as nucleophilic nitrenoids, with electron-rich alkynes, leading to imidazo-pyrimidines and imidazo-pyrazines. The calculation results suggest that the reaction mainly involves two plausible pathways leading to different products, since two carbon atoms of the asymmetric alkyne are attacked selectively by the aminide nitrogen atom. These reaction steps include C-C bond activation of the alkyne by the gold complex, a bimolecular nucleophilic attack, a closed-loop process and migration of the pyridine molecule to finally give cycloaddition products. The closed-loop process is the rate-limiting step for the whole catalytic reaction and the energy barrier shows that the pathway of the nucleophile onto the amide carbon atom of the alkyne with the electron-withdrawing group is favored. Through a detailed mechanistic investigation, we have explained the regioselectivity and the major/minor products observed by Davies et al. in gold(I)catalyzed [3 + 2] cycloaddition reactions of nucleophilic nitrenoids with electron-rich alkynes. Fig. 3 Free energy profiles calculated for the gold-catalyzed [2 + 3] cycloaddition of pyridinium N-(2-pyrimidinyl) aminide with thiophen-2ynamide. The relative free energies are given in kcal mol À1 . This journal is View Article Online found for b-TS2 in comparison to that for a-TS2 may be owing to the effect of the thienyl group. The next step for pyridine migration results in the new Au imidazole intermediate, b-IN3.Then, b-IN3, through a barrier-free process, easily generates the nal product (P3), regenerating the catalyst (CA). The whole catalytic cycle is exothermic by À65.2 kcal mol À1 . Fig. 4 Fully optimized structures of the intermediates and the transition states for pathway b are shown in Fig. 3, with selected bond lengths inÅ. The H atoms in structures are omitted for clarity. 62104 | RSC Adv., 2016, 6, 62099-62108 This journal is

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Gold‐Catalyzed Redox Synthesis of Imidazo[1,2‐a]pyridines using Pyridine N‐Oxide and Alkynes

Cited by 69 publications

References 52 publications

Design and Synthesis of Imidazo[1,2‐a]pyridines with Carboxamide Group Substitution and In silico Evaluation of their Interaction with a LuxR‐type Quorum Sensing Receptor

Design and Synthesis of Imidazo[1,2‐a]pyridines with Carboxamide Group Substitution and In silico Evaluation of their Interaction with a LuxR‐type Quorum Sensing Receptor

Cyclometalated Gold(III) Complexes: Synthesis, Reactivity, and Physicochemical Properties

Mechanism of the gold(i)-catalyzed synthesis of imidazo-pyrimidines and imidazo-pyrazines via [3 + 2] dipolar cycloaddition: a DFT study

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