واکنش‌های چندجزئی یکی از موفق‌ترین روش‌ها درزمینهٔ افزایش تنوع ساختاری و پیچیدگی مولکولی با استفاده از یک فرایند ساده است. این روش به‌عنوان فرایندی درحال‌توسعه برای تهیه ترکیبات دارویی، امکان گسترش بسیاری از ترکیبات شیمیایی را، با تنوع ساختاری بیشتر می‌دهد؛ بنابراین این واکنش‌ها که باعث تغییر و تحول اساسی در سنتز همه محصولات طبیعی شده؛ با سرعت زیادی در طول چند دهه گذشته گسترش‌یافته است. تا امروز بسیاری از واکنش‌های جدید سه و چهار‌جزئی معرفی‌شده‌اند؛ درصورتی‌که نمونه‌هایی از واکنش‌های "مرتبه بالاتر" که در آن پنج یا حتی تعداد اجزاء بیشتری در ظرف واکنش باهم ترکیب می‌شوند، به شکل قابل‌ملاحظه‌ای کمتر بررسی شده است. در پایان قرن بیستم با افزایش مزیت‌های "مولکول‌های بیولوژیک فعال" ، بررسی کاربرد این واکنش‌ها برای تهیه‌ی "مولکول‌های کوچک شبه دارو‌یی" در صنایع و دانشگاه‌‌‌ها افزایش ‌یافته است. از مزیت‌های این روش نسبت به ‌روش‌های دیگر، استفاده از مواد اولیه در دسترس، کم‌هزینه بودن، روش کار ساده، طیف گسترده کالا، ایجاد تنوع بالا در چند مرحله، سهولت اتوماسیون و... می‌باشد. هدف از این بررسی، توصیف تحولات ایجادشده در سال‌های اخیر، ایده‌ها، چالش‌ها و ارائه پیشنهاد‌هایی برای پیشرفت در این زمینه می‌باشد. پرونده مقاله

A beneficial and efficient one-pot three-component approach for the synthesis of spiro cyclic 2-oxindole derivatives has been described by the reaction of isatins, cyclic-1,3-diketones and 6-amino-1,3-dimethyluracil in presence of highly active HPA-ZSM-5 microporous catalyst. The zeolite catalyst has been synthesized and the catalyst has been thoroughly characterized by X-ray diffraction (XRD), field emission scanning electronic microscopy (FE-SEM), Fourier transform infrared (FT-IR), energy dispersive spectroscopy (EDS) and N2-adsorption analysis. HPA-ZSM-5 catalyst exhibited exceptional recyclability at least for 6 times and the surface acidity was not significantly changed. The best results were gained in H2O and we found the convincing results for the synthesis of spiro-pyrido-pyrimidine in the presence of HPA-ZSM-5 (10 mg) under ultrasound irradiation (40W). Experimental simplicity, wide range of products, excellent yields in short reaction times and low catalyst loading are some of the substantial features of this procedure. The present catalytic method is extensible to a wide diversity of substrates for the synthesis of a variety-oriented library of spiro-pyrido-pyrimidine indoline derivatives. پرونده مقاله

A beneficial and efficient one-pot three-component approach for the synthesis ofspiro cyclic 2-oxindole derivatives have been described by the reaction of isatins,cyclic-1,3-diketones and 6-amino-1,3-dimethyluracil in the presence of highlyactive HPA-ZSM-5 microporous catalyst. The zeolite catalyst has been synthesizedand the catalyst has been thoroughly characterized by X-ray diffraction (XRD),field emission scanning electronic microscopy (FE-SEM), Fourier transforminfrared (FT-IR), energy dispersive spectroscopy (EDS) and N2-adsorption analysis.HPA-ZSM-5 catalyst exhibited exceptional recyclability at least for 6 times andthe surface acidity was not significantly changed. The best results were gainedin H2O and we found the convincing results in the synthesis of spiro-pyridopyrimidinein the presence of HPA-ZSM-5 (10 mg) under ultrasound irradiation(40W). Experimental simplicity, wide range of products, excellent yields in shortreaction times and low catalyst loading are some of the substantial features ofthis procedure. The present catalytic method is extensible to a wide diversity ofsubstrates for the synthesis of a variety-oriented library of spiro-pyrido-pyrimidineindoline derivatives. پرونده مقاله

Mesoporous CoAl2O4 spinel nanocrystals ( nano-CoAl2O4 ) were synthesized and fully characterized by X- ray diffraction patterns (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), DLS (dynamic light scattering) and FT-IR. The nanocrystals promoted the preparation of quinazolinones via the one-pot, three component condensation reaction of benzaldehydes, isatoic anhydride, primary aromatic amine or ammonium acetate at 45°C under ultrasound irradiation. Experimental simplicity, great yields in concise times, the retrievability of the nanocrystals and performing the sonochemical methodology as an effective way in synthetic chemistry for the preparation of medicinally privileged heterocyclic molecules are some of the substantial features of this method. The present catalytic process is applicable to an extensive diversity of substrates for the preparation of a variety-oriented library of dihydroquinazolinones. The feasibility of doing one-pot synthesis under ultrasonic irradiation with a heterogeneous nanocrystal could improve the reaction rates and shorten the reaction times. پرونده مقاله

A rapid and efficient method for the synthesis of bis-thiazolidinones has been achieved by pseudo five-component reaction of aldehydes, ethylenediamine and thioglycolic acid in the presence of nano-NiZr4(PO4)6 as catalyst under microwave irradiation. Nano-NiZr4(PO4)6 has been characterized by powder X-ray diffraction, scanning electronic microscopy (SEM), energy dispersive spectroscopy (EDS), vibrating sample magnetometer (VSM), dynamic light scattering (DLS), thermogravimetric analysis (TGA) and FT-IR spectroscopy. In this research, microwave irradiation is used as a green and complementary technique for preparation of bis-thiazolidinones. Use of simple and readily available starting materials, excellent yields, short reaction times, reusability of the catalyst, low amount of catalyst and using of microwave as clean method are some advantages of this protocol. پرونده مقاله

An efficient and eco-friendly method for the one-pot synthesis of 14-aryl-14H-dibenzo [a,i]xanthene-8,13-dione derivatives has been developed in the presence of Fe3O4@SiO2 core-shell nanoparticles. The multi-component reactions of 2-hydroxy-1,4-naphthoquinone, β-naphthol and aldehydes were efficiently catalyzed using novel nano-scale materials under reflux conditions. The present method offers several advantages such as environmentally benign, simple work-up, excellent yield of products, short reaction times, little catalyst loading and facile catalyst separation. The nanomagnetic catalyst could be readily recovered using a simple external magnet and reused several times without any significant loss in activity. The catalyst was fully characterized by FT-IR, SEM, XRD, EDX and VSM analysis. پرونده مقاله

In this study, CuI nanoparticles as an efficient catalyst was used for the synthesis of 14-phenyl-8H-dibenzo[a,i]xanthene-8,13(14H)-diones using aldehydes, 2-naphthol and 2-hydroxynaphthalene-1,4-dione in aqueous media. In this study, it was found that water was the most effective solvent compared to others. Among several catalysts that were tested for this multi-component synthesis, CuI nanoparticles were the best catalyst with 4 mol% loading. The reusability of CuI nanoparticles was experienced for 6 times with a slightly decreased activity. The use of no hazardous organic solvent, atom economy, short reaction times, little catalyst loading, reusability of the catalyst and high yields of products are some of the important features of this protocol. پرونده مقاله

The preparation of trans-dihydrofurans has been achieved by a one-pot condensation reaction of 4-bromophenacyl bromide, aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione using biosynthesized CuO nanoparticles under reflux conditions in ethanol. CuO nanoparticles (CuO NPs) were prepared using extractof leaves of Ajuga chamaecistus Subsp. Scoparia. The key advantages of this process are the diastereoselective synthesis, reusability of the catalyst, low catalyst loading, excellent yields, short reaction times, simple workup and environmentally benign. Fully optimized structures of trans and cis dihydrofurans were obtained by B3LYP/6-31G(d,p) method. The structures of the prepared trans-2,3-dihydrofurans were fully characterized by 1H and 13C NMR spectra, IR spectra, and elemental analysis. پرونده مقاله

ZrP2O7 nanoparticles have been used as an efficient catalyst for the preparation of 2-aryl-5-methyl-2,3-dihydro-1H-3-pyrazolones by a simple one-pot four-component reaction of phenyl hydrazines, ethyl acetoacetate ,β-naphthol and benzaldehydes under microwave irradiation in good to excellent yields. When the reaction was carried out using ZrOCl2.8H2O, ZrO2 and ZrP2O7 NPs as the catalyst, the product were obtained in moderate to good yield. The highest yield 92% was reached when the reaction was performed with 0.6 mol% of catalyst loading. Atom economy, green reaction, short reaction times, easy isolation of the targeted molecules, recovery and reusability of the catalyst are some of the important features of this protocol. پرونده مقاله

ZrP2O7 nanoparticles (NPs) as an efficient catalyst have been used for the preparation of 1,6-diamino-2- oxo-4-phenyl-1,2-dihydropyridine-3,5-dicarbonitrile derivatives via one-pot coupling of hyrazine hydrate, ethyl cyanoacetate, malononitrile and aromatic aldehydes under reflux conditions in ethanol. Using this method we obtained low reaction times, easy isolation of the targeted molecules, excellent yields. پرونده مقاله

Nanocrystalline ZnZr4(PO4)6 ceramics as an efficient catalyst have been used for the preparation of methyl 6-amino-5-cyano-4-aryl-2,4-dihydropyrano[2,3-c]pyrazole-3-carboxylates by the four component reaction of dimethylacetylenedicarboxylate, hydrazinehydrate, malononitrile and aromatic aldehydes in water at room temperature. In this research Nano-ZnZr4(PO4)6 coordinate with the active groups(particular C=O, C≡N and active H) thus increasing the activity of the groups. Also this nanoscale heterogeneous catalysts present higher surface areas which are mainly responsible for their catalytic activity. These surface atoms behave as the centers where the chemical reactions could be catalytically activated. The key advantages of this process are high yields, shorter reaction times, reusability of catalyst, easy work-up, milder reaction conditions and environmentally benign. پرونده مقاله

A proper, atom-economical, straightforward one-pot multicomponent synthetic route for the synthesis of benzopyranophenazines has been presented by the reaction of hydroxynaphthoquinone, o-phenylenediamine, benzaldehydes, and malononitrile with crosslinked sulfonated polyacrylamide (Cross-PAA-SO3H) attached to nano-Fe3O4as an efficient heterogeneous solid acid catalyst under ultrasonic irradiations in ethanol. Experimental simplicity, wide range of products, excellent yields in short reaction times and applying the sonochemical methodology as an efficient method and innocuous means of activation in synthetic chemistry for the preparation of medicinally privileged heterocyclic molecules are some of the important features of this method. The present catalytic procedure is extensible to a wide diversity of substrates for the synthesis of a variety-oriented library of benzopyranophenazines. پرونده مقاله

An efficient green route for the preparation of naphthoxazinones, applying a three-component one-pot condensation reaction of 2-naphthol, aromatic aldehyde and urea in the presence of nano silica supported ferric chloride under solvent-free conditions has been developed. The present procedure offers several advantages such as short reaction time, simple workup, recovery and reusability of the catalyst. پرونده مقاله