The Eosin Y photocatalyzed Biginelli protocol has been established by a cascade one-pot three-component reaction of primary alcohols, α-ketoester, and urea to provide pharmacologically promising ...3,4-dihydropyrimidin-2(1H)-ones in high yields. The key benefits of the present scheme are the capability to allow operational simplicity, readily available substrates, straightforward workup and high yields. This Eosin Y based photocatalytic approach can permit conquering traditional metal-catalyzed reactions in a sustainable manner, thus delivering economic and environmental rewards.
Graphical abstract
An environmentally benign protocol for the synthesis of 3,4-DHPMs has been developed using inexpensive molecular oxygen, visible light as green energy source and eosin Y as photoreceptor-cum-sensitizer. The utilized photoreceptor revealed its unique properties in rapid intersystem crossing, high photo and chemical stability, ease of separation and high catalytic efficiency.
3+2+2 Cycloaddition reactions are of key importance in organic chemistry for the synthesis of seven‐membered mono‐ and condensed carbocycles. This review article summarises the different reports on ...transition‐metal‐catalysed 3+2+2 cycloaddition reactions since 2000. Different transition‐metals, such as Ni, Rh, Pd, Co, or Ru, which have been earlier reported for higher order 3+2+2 cycloaddition reactions are summarized in this article. The 3+2+2 cycloadditions of different functionalized substrates afford cycloheptane derivatives, 6–7,5–7 condensed bicyclic carbocycles, or 5–7–5 or 6–7–5 condensed tricyclic carbocycles. These higher order cycloaddition reactions may provide an easy route for the total synthesis of natural products, or as a preferable key synthetic step leading to final structure.
3+2+2 Cycloaddition reactions are important for the synthesis of seven‐membered carbocycles. 3+2+2 Cycloadditions of different substrates afford cycloheptane derivatives, 6–7, 5–7 condensed bicyclic carbocycles, or 5–7–5 and 6–7–5 condensed tricyclic carbocycles. Higher‐order cycloaddition reactions may provide an easy route for the total synthesis of natural products, or as a key synthetic step towards the final structure. This review summarizes the different reports on 3+2+2 cycloaddition reactions since 2000.
Abstract
Butadienyl ketene is a useful intermediate because of its role as a 2p-component in cycloaddition reactions with a variety of substrates such as simple or conjugated imines and dienes. This ...review article summarizes recent reports on the generation of butadienyl ketene in situ and their cycloaddition reactions to afford heterocyclic systems. The chemistry of butadienyl ketene is explored with a focus on its 2+2 and 4+2 cycloaddition reactions with a variety of imines and azadiene derivatives such as 1,3-diazabuta-1,3-dienes, for the synthesis of four- and six-membered heterocycles, respectively.
The sustainable development of point-of-care testing (POCT) for spermine detection is important to check for food spoilage, early diagnosis of various malignancies and diminished anticonvulsant drug ...carbamazepine response in chronic epilepsy. Herein, the synthesis, characterization and spectroscopic properties of perylene diimide EA-PDI∩Cu2+ complex based nanoparticles towards spermine were studied in detail. This EA-PDI∩Cu2+ complex can be used for the ultrasensitive detection of spermine as low as 86.3 nM (UV-vis) and 90 pM (fluorescence) in aqueous medium, in urine and blood serum samples (recovery 99 ± 3) and in the solid state (0.1 μg L−1), and EA-PDI shows minimal cytotoxicity to cells and can easily enter into Human Osteosarcoma MG-63 cells for bio-imaging of Cu2+ and spermine. This EA-PDI∩Cu2+ complex can be established as a cost-effective method to develop a diagnostic kit for POCT of spermine in terms of a solution-based test kit for real time detection of spermine in vapor and solution form released from fermented food samples.
Abstract
A highly eco-friendly greener approach based on the mechanochemical method using mortar and pestle is explored for the preparation of a variety of functionalized 4-thiazolidinones. The ...developed methodology does not require the use of harmful or expensive reagents and organic solvents and requires very less reaction time with easy isolation. The explored greener approach for the synthesis of 4-thiazolidinones is an important in terms of their usefulness for their valuable pharmacological properties.
Now with nickel: 3C+2C+2C cycloadditions involving non‐activated alkylidenecyclopropanes provide a practical entry to a variety of interesting 6,7‐fused bicyclic systems (see scheme; ...cod=1,5‐cyclooctadiene). DFT calculations, combined with experimental data, suggest that the catalytic cycle involves the initial formation of 1‐alkylidenenickelacyclobutane intermediates, such as 1.
The regioselective nitroso Diels–Alder (NDA) cycloadditions of 3-dienyl-2-azetidinones with nitrosobenzene to generate oxazine-substituted β-lactams in excellent yields are reported. The amidiolytic ...ring opening of the cycloadducts with sodium methoxide followed by iodocyclization using I
2/K
2CO
3 etiquette to capitulate previously unknown, multisubstituted pyrroloxazine in outstanding yields is also accounted.
![Nickel-Catalyzed [3+2+2] Cy...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1433-7851/small "Nickel-Catalyzed [3+2+2] Cycloadditions between Alkynylidenecyclopropanes and Activated Alkenes")
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