Ultrasound-Assisted Iodination of Imidazo[1,2-α]pyridines Via C–H Functionalization Mediated by tert-Butyl Hydroperoxide
Ontology highlight
ABSTRACT:
SUBMITTER: Yang H
PROVIDER: S-EPMC8515396 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:In the title compound, C16H16Cl2N4, the imidazole ring mean plane makes a dihedral angle of 70.01 (1)° with the phenyl ring. The Cl atoms deviate by -0.0472 (6) and 0.0245 (8) Å from the plane of their attached benzene ring. In the crystal, mol-ecules are linked via pairs of C-H⋯N hydrogen bonds, forming inversion dimers.
| S-EPMC3685091 | biostudies-literature
Project description:In the title compound, C18H23N5, the imidazole ring makes a dihedral angles of 3.96 (8) and 19.02 (8)°, respectively, with the pyrazine and benzene rings while the dihedral angle between the pyrazine and benzene rings is 16.96 (7)°. In the crystal, mol-ecules are linked via N-H⋯N hydrogen bonds, forming chains along [010]. These chains are linked by C-H⋯N hydrogen bonds, forming two-dimensional networks lying parallel to (001).
| S-EPMC3629650 | biostudies-literature
Project description:In the title imidazo[1,2-a]pyridine derivatives, N-tert-butyl-2-(4-meth-oxy-phen-yl)-5-methyl-imidazo[1,2-a]pyridin-3-amine, C19H23N3O, (I), and N-tert-butyl-2-[4-(di-methyl-amino)-phen-yl]imidazo[1,2-a]pyridin-3-amine, C19H24N4, (II), the 4-meth-oxy-phenyl ring in (I) and the 4-(di-methyl-amino)-phenyl ring in (II) are inclined to the respective imidazole rings by 26.69?(9) and 31.35?(10)°. In the crystal of (I), mol-ecules are linked by N-H?N hydrogen bonds, forming chains propagating along the [001] direction. The chains are linked by C-H?? inter-actions, forming layers parallel to the (010) plane. In (II), the crystal packing also features N-H?N hydrogen bonds, which together with C-H?N hydrogen bonds link mol-ecules to form chains propagating along the c-axis direction. The chains are linked by C-H?? inter-actions to form layers parallel to the (100) plane. Inversion-related layers are linked by offset ?-? inter-actions [inter-centroid distance = 3.577?(1)?Å]. The inter-molecular inter-actions of both compounds were analyzed using Hirshfeld surface analysis and two-dimensional fingerprint plots.
| S-EPMC6281107 | biostudies-literature
Project description:New conformationally extended dipeptide surrogates based on an imidazo[1,2-a]pyridine scaffold are described. Efficient synthesis and incorporation into host peptides affords structures with native side-chain functionality and hydrogen bonding elements on one face of the backbone. Structural analysis by NMR suggests that model peptidomimetics adopt a β-strand-like conformation in solution.
| S-EPMC3528799 | biostudies-literature
Project description:Background?-Bromination of the side chain of aromatic ketones using NBS in the presence of p-toluenesulfonic acid (p-TsOH) in acetonitrile is very common. However, regioselective bromination of bis and tris(?-bromoacetophenones) with NBS in the presence of p-TsOH in acetonitrile under microwave irradiation is quite novel. The bis- and tris(?-bromoacetophenones) are used in synthesis of bis and tris(heterocycles). bis(heterocycles) have received a great deal of attention, because many biologically active natural and synthetic products have molecular symmetry. The use of the pressurized microwave irradiation is very advantageous to many syntheses and provide a large rate enhancement.ResultsBis and tris(?-bromoacetophenones) were obtained as single monobrominated derivatives in a shorter time than the conventional conditions. The results clearly demonstrate the better reactivity and selectivity of NBS/p-TsOH/CH3CN as a brominating mixture under microwave conditions. The reaction of bis and tris(?-bromoacetophenone) with 2-aminopyridine and 2-aminopyrimidine proceeded smoothly in a mixture of anhydrous ethanol and DMF under reflux or using 300 W/105°C/ 20 min microwave irradiation conditions to afford the corresponding bis(imidazo[1,2-a]pyridine), bis(imidazo[1,2-a]pyrimidine) and tris(imidazo[1,2-a]pyridine) derivatives in moderate to excellent yields. The carbonyl analogue of the targeted bis(imidazopyridines) could be synthesized by the reaction of N,N-dimethyl-N'-(pyridin-2-yl)formimidamide with bis(?-bromoacetophenone) in refluxing ethanol. The structures of the newly synthesized compounds were confirmed by their spectral data as well as their elemental analyses.ConclusionIn conclusion, selective ?-bromination of bis- and tris(acetophenones) has been accomplished efficiently utilizing NBS/p-TsOH/CH3CN under microwave irradiation. In addition, a facile synthesis of novel series of bis- and tris(imidazopyridine) and bis(imidazopyrimidine) derivatives.
| S-EPMC3698004 | biostudies-literature
Project description:Multicomponent reactions (MCRs) are robust tools for the rapid synthesis of complex, small molecule libraries for use in drug discovery and development. By utilizing MCR chemistry, we developed a protocol to functionalize the C-3 position of imidazo[1,2-a]pyridine through a three component, decarboxylation reaction involving imidazo[1,2-a]pyridine, glyoxalic acid, and boronic acid.
| S-EPMC6284400 | biostudies-literature
Project description:In the crystal structure of the title compound, C(10)H(22)O(2), co-operative chains of O-H?O hydrogen bonds are established by intra- as well as inter-molecular inter-actions. These hydrogen bonds connect the mol-ecules into infinite strands along [100], with a binary level graph-set descriptor C(2) (2)(4). Excluding the H atoms on the hydr-oxy groups, the mol-ecule shows non-crystallographic C(2) symmetry.
| S-EPMC2968115 | biostudies-literature
Project description:Aqueous L-selenomethionine (SeMet) embryo exposures represent a rapid and simplified method for investigating the embryotoxic effects of SeMet. Using zebrafish (Danio rerio) as a model organism, the objective of the present study was to characterize the effects of waterborne exposure to both SeMet and tert-butyl hydroperoxide (tBOOH) to early life stages of zebrafish pre-treated with the antioxidant tert-butyl hydroquinone (tBHQ) in an attempt to investigate the mechanism of Se toxicity as it relates to oxidative stress. During the initial concentration range finding experiment, recently fertilized embryos were exposed for five days to 5, 25, 125, and 625 µg Se/L (as SeMet). These exposures informed the second experiment in which embryos were exposed to two concentrations of SeMet (25 and 125 µg Se/L) and 75 mg/L tBOOH either with (tBOOH-t, 25-t, 125-t) or without (tBOOH, 25, 125) a 4 h 100 µg/L tBHQ pre-treatment. Survival, hatchability, time to hatch, the frequency and severity of deformities (total and type), and changes in the expression of seven antioxidant-associated genes were determined. Exposures to SeMet and tBOOH reduced hatchability, increased time to hatch, decreased survival, increased the incidence and severity of deformities, and increased glutathione-disulfide reductase (gsr) expression in the pre-treated tBOOH treatment group.
| S-EPMC6789818 | biostudies-literature
Project description:In the title compound, C(18)H(40)N(2)O(2)S(2), a vicinal diamine derivative, the crystal structure is stabilized by two intra-molecular N-H?O hydrogen bonds. The distance between the two kernel chiral C atoms is 1.580?(2)?Å.
| S-EPMC2968083 | biostudies-other
Project description:The imidazo[1,2-a]pyridine moiety is present in drugs with several biological activities. The most direct way of obtaining this nucleus is the Groebke-Blackburn-Bienaymé three-component reaction (GBB-3CR) between aminopyridines, aldehydes, and isocyanides under both Lewis and Brønsted acid catalysis. However, several catalysts for this reaction have major drawbacks such as being expensive, extremely dangerous, strong oxidizing, and even explosive. In this scenario, heteropolyacids emerge as greener and safer alternatives due to their very strong Brønsted acidity. In particular, phosphotungstic acid (HPW) is an economical and green attractive catalyst for being cheap, non-toxic, and is known for its chemical and thermal stability. Herein, we report a straightforward approach to the GBB-3CR using HPW as catalyst in ethanol under microwave (μw) heating. This convenient environmentally benign methodology is broad in scope, provides the heterobicyclic products in high yields (up to 99%), with a low catalyst loading (2 mol %) in only 30 minutes, and allows the successful use of aliphatic aldehydes, substrates not so frequently explored with most usual catalysts for this reaction. Furthermore, the aforementioned advantages make this methodology very attractive and superior to the existing ones.
| S-EPMC10964034 | biostudies-literature