Synlett

This report outlines an intramolecular oxidative annulation process involving N-substituted o-amino phenylacetylene, performed under electrochemical conditions, which yields substituted quinoline in an undivided cell at room temperature. The reaction features mild conditions, requiring neither external oxidants nor metals, and achieves yields that range from good to excellent. Moreover, the synthetic potential of quinoline has been demonstrated resulting in the synthesis of substituted polycyclic isoindolinone and (aza-)isoindolinone compounds.

1,5-Diaza-3,7-diphosphacyclooctane (P2N2) scaffolds represent a readily accessible, tunable ligand class for transition metals. However, despite their prevalence in areas such as electrocatalysis and coordination chemistry, P2N2 ligands have been rarely used to make catalysts for organic synthesis. Research into Mizoroki–Heck-type aldehyde, alcohol, and alkene arylation reactions has revealed that the P2N2 family outperforms many commonly used phosphines. This Synpacts article summarizes our work and provides a broad overview on the preparation and application of P2N2 ligands in organic synthesis. It also serves to highlight how a simple, modular class of ligands can solve contemporary challenges with transition-metal catalysis, including novel reactivity and exceptional regioselectivity.

We have synthesized a series of tetramethylpiperidinyl triazolopyridazine derivatives and screened the molecules for their biological activity against a cancer (NCI-H460) cell line. Among the tested molecules, 2-[3-(2,2,6,6-tetramethylpiperidin-4-yl)-3H-[1,2,3]triazolo[4,5-c]pyridazin-6-yl]-5-(2H-1,2,3-triazol-2-yl)phenol significantly inhibited cell growth with an IC50 value of 5.2 μM. We hope that this study will help in the development of better candidates for the treatment of lung cancer.

A concise and efficient stereospecific approach for the total synthesis of diplodialide C (R,R and S,S isomers) has been demonstrated using chiral homoglycidol and propylene oxide as a source of starting material. Further oxidized ketolide product derived from diplodialide C (S,S isomer) was applied to the formal synthesis of (–)-curvularin following reported known literature.

We report here a Ni-NPs-catalyzed one-pot synthesis of 2-alkyl/aryl quinazolinone motifs via acceptorless dehydrogenation of alcohol, condensation of an aldehyde intermediate with 2-aminobenzamide, followed by a second dehydrogenation of the cyclized intermediate. The protocol is atom-economical and require earth-abundant Ni as the catalyst. The present report involves the annulation of 2-aminobenzamide with various types of primary alcohols, including aryl/heteroaryl methanol, and aliphatic alcohols, and produces high yields of the desired products under neat conditions. The catalyst was synthesized via a high-temperature pyrolysis strategy, using ZIF-8 as the sacrificial template. The Ni NPs@N-C catalyst was characterized by XPS, HR-TEM, HAADF-STEM, XRD, and ICP-MS. The catalyst is stable even in air at room temperature and displayed excellent activity in the acceptorless dehydrogenative coupling synthesis of quinazolinones and could be recycled five times without appreciable loss of its activity.

For hundreds of years, it seems that people have needed stirring to conduct chemical experiments. This operation can be seen everywhere in chemical, pharmaceutical, and materials laboratories and factories. People generally believe that stirring helps with processes such as material dispersion, dissolution, and collision, thereby enabling more-efficient reactions. However, why do chemical reactions that occur in Nature not require stirring? What are the facts? For this purpose, we investigated a total of 329 organic chemical reactions in eight categories and 25 types, including 26 chemical reactions magnified to gram or even kilogram levels. Under the same conditions of temperature, humidity, pressure, and reaction time, we compared the reaction yields under stirring and standing conditions. More than 600 results showed that stirring or not stirring had almost no effect on the efficiency of chemical reactions in solution. If most chemists performing reactions turned off the agitator, it would not be difficult to imagine how much electricity could be saved!

N-Formylation of anilines using a renewable aleuritic acid as an eco-friendly and sustainable formylating source has been developed. para-Substituted anilines generally provided good yields, while moderate yields were observed with meta- and ortho-substituted derivatives. In situ generated formic acid through oxidative cleavage of aleuritic acid serve as a formyl source, which has been confirmed through control experiments.

Isotopic labeling is an attractive modality that has been widely used in many aspects of chemistry, the life sciences, and medical research; especially deuterated drugs and radioactive molecules have been used in the diagnosis and treatment of cancer and neurodegenerative diseases. The widespread application and rapid development of isotopically labeled molecules has led to an increased demand for new isotopic labeling chemical methods to synthesize highly specific molecules bearing defined nuclides. Multicomponent reactions (MCRs) are modular build-up approaches for the rapid generation of complex molecules often containing biologically relevant scaffold structures. There is great potential to use MCRs to construct isotopically labeled molecules because assembly speed and reaction diversity are key advantages of MCR. In this review, we provide an overview of the recent literature on this topic that can provide insight into the application of MCRs in the field of isotopic labeling.

A new method for the O-methylation of cinnamic acid employing DMSO as the methylating agent has been devised, employing a Ni-DMAP complex as catalyst along with Ag2O and dimethylamine as additives. This protocol demonstrates broad substrate compatibility and good tolerance towards various functional groups. The key advantages of this approach include the utilization of cost-effective catalysts, moderate to high yield of the products, and short reaction time.

The impetuous development of the pharmaceutical industry and material science stimulates the search for new synthetic approaches and new methods for the synthesis and functionalization of aza-heterocycles; these are some of the key objectives of modern organic chemistry. As a result, an advanced method towards the synthesis of functionalized N-heterocycles that circumvents the limitations associated with traditional methods needs to be devised. In recent decades, rearrangement/reorganization reactions have emerged as a powerful tool for the efficient synthesis of the aza-heterocycle. In this illustration, we summarize some our recent efforts in the development of few complex aza-heterocyclic cores.1 Introduction2 Skeletal Rearrangement of Small Heterocycles via Domino Ring-Opening and Ring-Closing (DROC) Strategy3 Ru(II)-Catalyzed Skeletal Rearrangement of the Quinazoline Ring4 Lewis Acid Catalyzed Skeletal Rearrangement of Furans to Indolizine Cores5 Skeletal Rearrangement of Donor–Acceptor Cyclopropanes via Domino Ring-Opening and Ring-Closing (DROC) Strategy6 Lewis Acid Mediated Skeletal Rearrangement of Donor–Acceptor Spirocyclopropylpyrazolones7 Skeletal Rearrangement through Ring Distortion Strategy8 Conclusion