An effective and novel heterogeneous beta zeolite supported CuO (Cuβ) catalyzed double hydroamination of alkynes for the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones has been achieved in a ...solvent‐free condition. Cuβ zeolite was synthesized by impregnation method. The synthesized Cuβ was characterized by X‐ray diffraction, Fourier transformation infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and X‐ray photoelectron spectroscopy. Pure Hβ (18 % yield) or Nano CuO (44 % yield) displayed poor catalytic activity, whereas 1 % Cuβ (96 % yield) showed higher catalytic activity for double hydroamination of alkynes due to the synergistic effect of CuO and Hβ zeolite in the reaction. The new protocol offers an appealing approach to a number of di‐substituted quinazolinones with decent to excellent yields. The catalyst has been successfully recycled for up to 5 consecutive cycles.
An efficient heterogeneous 1 % Cuβ zeolite catalyzed double hydroamination of terminal alkynes for the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones is achieved in a solvent‐free environment. This method offers an appealing approach to a number of di‐substituted quinazolinones with decent to excellent yields.
A simple approach for the formation of imines by condensation of ketones and anilines over heterogeneous catalyst (Hβ zeolite) has been successfully developed. The present catalytic system scope was ...explored for various aromatic ketones and anilines. Furthermore, Hβ zeolite can be easily separable and recycled several times (five times) without considerable loss of its catalytic activity.
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A convenient practical approach for the synthesis of 2-(pyridin-2-yl)ethanols by direct benzylic addition of azaarenes and aldehydes under catalyst- and solvent-free conditions is reported. This ...reaction is metal-free, green, and was carried out in a facile operative environment without using any hazardous transition metal catalysts or any other coupling reagents. Different aromatic aldehydes and azaarenes were monitored, and the yields of the resulting products were moderate to excellent. We accomplished several azaarene derivatives under neat conditions through a highly atom-economical pathway. To evaluate the preparative potential of this process, gram-scale reactions were performed up to a 10 g scale.
The synthesis of 2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation of anthranilamide with ketones in aqueous media using Hβ zeolite is reported. The scope of the reaction was explored by various ...ketones such as aromatic, aliphatic and cyclic ketones. Based on the preliminary mechanistic results, a tentative mechanism for the formation of 2,3-dihydroquinazolin-4(1H)-ones using zeolite catalyst (Hβ) is predicted. The reusability study, large-scale experiment and water as solvent showed significant benefits of this catalytic protocol in comparing to earlier methods.
A novel metal‐free catalytic one‐pot approach has been developed for the esterification of aralkyl ketones with alcohols under open‐air atmospheric conditions. The inexpensive iodide/oxone reagent ...system allowed the cascade C(sp3)−H bond oxygenation, selective C−C bond cleavage and esterification through the both radical and ionic pathways in a stepwise manner in one‐pot. This mild, convenient and economically viable catalytic method tolerates the various functional groups to provide the corresponding alkyl benzoates in up to 98% yields with up to 99% selectivity. The efficiency and feasibility of scale‐up of the present catalytic system was demonstrated with gram scale experiments (up to 10 gram scale).
An unprecedented metal‐free catalytic protocol for the esterification of aryl alkyl ketones with alcohols in one‐pot cascade manner using eco‐friendly reagents has been developed.
A simple heterogeneous catalytic process has been established for the single-step synthesis of fused benzoxazinones, quinazolinones, and thiadazines through Markownikoff's hydroamination followed by ...intramolecular cyclization using Cuβ zeolite. The probability and limitations of this catalytic approach were explored using various substrates. The efficiency and feasibility of scaling up the current catalytic system were demonstrated through gram-scale experiments. Moreover, the catalyst was reused for up to five cycles with no noticeable decrease in its catalytic effectiveness. Furthermore, the synthesized compounds were subjected to in vitro assessment to determine their potential as anticancer agents against human cervical epithelioid carcinoma (HeLa), mouse breast cancer (4T-1), and human lung adenocarcinoma (A-549) cell lines. Cytotoxicity studies revealed that 3f, 3b′, 3d′, and 3g′ compounds exhibit anti-cancer activity against breast, cervical and lung cancer cells. Additionally, their antimicrobial activity against bacteria and yeast was also evaluated. The compound 3i exhibited superior antifungal activity against Candida albicans.
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•Cuβ zeolite shows good catalytic activity for synthesis of N-heterocyclic moieties.•Potentiality of this method is ensured with various substrates in good yields.•This approach benefits industrial applications by gram scale experiments.•The catalyst was successfully reused for up to five cycles.•The obtained products were found to be biologically active.
We investigated direct addition reaction of beta-diketone with several alcohols and alkenes employing solid acid zeolites (HY & Hbeta). The presence of acidic sites and the porous structures exhibits ...and influences the catalytic activity. These heterogeneous catalysts were used directly for the nucleophilic addition/substitution reactions. HY zeolite was utilized for the reaction of various aromatic alcohols containing substituents like electron-donating groups, halogens, diphenyl alcohols, propargylic alcohols with acetyl acetone and gave the respective products in 14-99% yields. Hbeta zeolite was used for the reaction of several substituted alkenes with acetyl acetone and afforded their corresponding products from 35 to 98% yields. The validation of large-scale experiments (10 mmol) adds additional dividend to this protocol. Moreover, these heterogeneous zeolites were readily separated from the reaction mixture by simple filtration process. The efficiency of these zeolites (HY and Hbeta) for recyclability was proved for five cycles.
We investigated direct addition reaction of β-diketone with several alcohols and alkenes employing solid acid zeolites (HY & Hβ). The presence of acidic sites and the porous structures exhibits and ...influences the catalytic activity. These heterogeneous catalysts were used directly for the nucleophilic addition/substitution reactions. HY zeolite was utilized for the reaction of various aromatic alcohols containing substituents like electron-donating groups, halogens, diphenyl alcohols, propargylic alcohols with acetyl acetone and gave the respective products in 14–99% yields. Hβ zeolite was used for the reaction of several substituted alkenes with acetyl acetone and afforded their corresponding products from 35 to 98% yields. The validation of large-scale experiments (10 mmol) adds additional dividend to this protocol. Moreover, these heterogeneous zeolites were readily separated from the reaction mixture by simple filtration process
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The efficiency of these zeolites (HY and Hβ) for recyclability was proved for five cycles.
Graphical Abstract
A wide range of quinazolin-4(3H)-ones have been synthesized from readily accessible precursors such as anthranilamide and 1,3-diketones. This reaction was promoted by the heterogeneous beta zeolite ...as the catalyst via a selective cleavage of the C–C bond of 1,3-diketones. This reaction went smoothly with various 1,3-diketones (cyclic and acyclic) affording 2-aryl and 2-alkyl substituted quinazolin-4(3H)-ones in good to excellent yields. The notable point of this strategy is that it can avoid the involvement of toxic transition metals, additives and corrosive oxidants establishing this method as green and feasible. Besides, this method displays its capacity for gram-scale reactions (up to 10 g). Moreover, in this process the recyclability of the recovered catalyst without drastic changes until 5 cycles have been presented.
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•Hβ zeolite depicted good catalytic activity for synthesis of 2-methylquinazolin-4(3H)-ones.•Potentiality of this method is conferred with different cyclic and acyclic 1,3-diketones.•This process is green and developed without any immobilizations or additives.•This is sustainable and first solvent-free protocol with heterogeneous catalyst.•Mainly, this approach presents synthetic utility by gram scale experiments.
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