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A high-yielding fast spirocyclization of easily available indol ynones has been developed by applying N-iodosuccinimide. The formation of the desired product occurs in an atom-economical way, under mild conditions, instantly after the addition of the reagent. The expected 1,2-rearrangement was not observed. The procedure represents a metal free spirocyclization of indoles with an opportunity for further functionalizations. [ABSTRACT FROM AUTHOR]

We report herein an efficient gold(I)-catalyzed post-Ugi domino dearomatization/ ipso-cyclization/Michael sequence that enables access to libraries of diverse (hetero)arene-annulated tricyclic heterocycles. This process affords novel complex polycyclic scaffolds in moderate to good yields from readily available acyclic precursors with excellent chemo-, regio-, and diastereoselectivity. The power of this strategy has been demonstrated by the rapid synthesis of 40 highly functionalized polyheterocycles bearing indole, pyrrole, (benzo)furan, (benzo)thiophene, pyrazole, and electron-rich arene groups in two operational steps. [ABSTRACT FROM AUTHOR]

An efficient, catalyst-free, microwave-assisted approach has been developed for the synthesis of 2-aryl/alkyl-3-(1H-benzo[d]imidazol-2-yl)-2,3-dihydroquinazolin-4(1H)-one derivatives by condensing 2-aminobenzamides with various aliphatic, aromatic, and heterocyclic aldehydes. This catalyst-free approach exhibited good functional group compatibility and produced the desired products in good to excellent yields in just 10–20 min. This approach can be seen as a better alternative of the metal-catalyzed protocols used for the synthesis of this class of compounds. The formation of desired compound has also been confirmed by X-ray analysis. [ABSTRACT FROM PUBLISHER]

A microwave-assisted highly efficient intermolecular domino carbopalladation/CH functionalization sequence has been developed to access bis-heteroaryl frameworks in a single operation. The reaction involves carbopalladation of the halogenated acrylamides or phenylpropiolamides by the Pd(0) catalysis, followed by the direct (hetero)arylation to give products with good to excellent yields. The synthetic utility of this method was also extended towards the application of the Ugi-adduct as the starting material. [ABSTRACT FROM AUTHOR]

Heterocyclic fused α-methylene β-lactams were successfully synthesized by a post-Ugi InIII-catalyzed intramolecular addition reaction. Switching from InCl3 to AlCl3 led to the regioselective synthesis of α,β-unsaturated γ-lactams. Moreover, replacing terminal alkynes by substituted alkynes in the Ugi adducts resulted in the exclusive formation of γ-lactams with both catalytic systems. [ABSTRACT FROM AUTHOR]

A cascade transformation involving the Ugi reaction followed by 5-endo-dig carbocyclization and retro-Claisen fragmentation providing access to a 1H-pyrrol-2(5H)-one core is described. The operating protocol is very similar to the typical Ugi reaction settings, while the overall outcome results from the application of a 3-substituted propiolic acid and a phenylglyoxal as acid and aldehyde components, respectively. The utility of process is demonstrated through the synthesis of a small library of 5-oxo-2,5-dihydro-1H-pyrrole-2-carboxamides. [ABSTRACT FROM AUTHOR]

An efficient microwave-assisted synthesis of tertiary propargylamines has been developed by copper(I)-catalyzed decarboxylative A3-coupling reaction of an alkynylcarboxylic acid with a secondary amine and an aldehyde. A wide range of diversely substituted propargylamines could be synthesized in high yields. The optimal reaction conditions are also effective for 3-alkylpropiolic acids and for terminal propiolic acid. [ABSTRACT FROM AUTHOR]

A novel microwave-assisted protocol allowing the successful application of 2-aminoimidazoles in the Groebke-Blackburn-Bienaymé reaction for the facile construction of the 1H-imidazo[1,2-a]imidazol-5-amine core was developed. [ABSTRACT FROM AUTHOR]

A highly efficient method for the preparation of trisubstituted furo[2,3-b]pyrazines has been developed. Sonogashira coupling reaction with the readily available 1-(4-methoxybenzyl)-3,5-dichloropyrazin-2(1H)-ones was followed by silver-catalyzed heteroannulation to provide the corresponding 2-chlorofuro[2,3-b]pyrazines in excellent yields. The latter were subjected to Suzuki or Buchwald-Hartwig coupling reaction for further decoration. [ABSTRACT FROM AUTHOR]

Most of the human bacterial infections are associated with the biofilm formation and the natural tolerance of biofilms to antibiotics challenges treatment. Because of their low immunity, cancer patients are especially susceptible to bacterial infections. Compounds with anti-biofilm activity could therefore become a useful adjunct to chemotherapy, in particular if they also show antiproliferative activities. Taking this into consideration and as a result of our continuous interest in 2-aminoimidazole derivatives, we have designed and synthesized a series of novel polysubstituted 2-aminoimidazoles ( 20 a-x ). The compounds were evaluated against a panel of three bacterial strains for their biofilm and planktonic growth inhibitory activity and most of them show promising results. Furthermore, the synthesized compounds were evaluated against various cancer cell lines and almost all the compounds were found to possess potent antiproliferative activity. The substitution pattern at the C-4 position and the aryl carboxamide ring at the N-1 position have major effects on the biofilm inhibitory and antiproliferative activity. Especially, the introduction of a p -methyl group at the carboxamide ring remarkably enhances both the anti-biofilm and antiproliferative activity. The two most potent compounds ( 20 i & 20 r ) were further studied for their antiproliferative activity and a flow cytometer-based cell cycle experiment was performed, which revealed their capability to induce G2/M phase cell cycle arrest. Based on these results, these two new compounds having potential to target both cancer proliferation and microbial biofilms might be used in single drug monotherapy. [ABSTRACT FROM AUTHOR]

A three-component reaction of a 2-aminoazine, a 2-oxoaldehyde, and a cyclic 1,3-dicarbonyl compound providing access toward a novel class of imidazo[1,2-a]azine derivatives was developed and studied. The scope of the process was thoroughly explored under three different reaction conditions resulting in the generation of a small library of title compounds and highlighting the possibility of case-specific approach. [ABSTRACT FROM AUTHOR]

Abstract: A novel three-step approach leading to [1,2,3]-triazolo[1,5-a][1,4]benzodiazepines in moderate to good yields has been developed. The key step is an unprecedented one-pot Cu-catalyzed azidation–cyclization reaction of ortho-bromobenzylpropargylamines. [Copyright &y& Elsevier]

Abstract: A gold-catalyzed regioselective heteroannulation strategy has been developed for the concise and efficient synthesis of imidazo[1,2-a]pyrazinones. The protocol allows the introduction of diversity via the application of substituted propargyl amines or via Suzuki-coupling of the generated imidazo[1,2-a]pyrazinones with various (het)aryl boronic acids. [Copyright &y& Elsevier]

The article presents chemical equations related to the article "A Domino Ugi/Michael Approach for the Synthesis of α,β-Unsaturated γ-Lactams" by Zhenghua Li and others, published in the "Tetrahedron Letters" in 2016.

Readily available starting materials are used in the tandem A3-coupling-azidation-cyclization sequence to obtain potentially bioactive diazepine analogues. [ABSTRACT FROM AUTHOR]

Heterocyclic fused α-methylene β-lactams are synthesized by a InCl3-catalyzed intramolecular addition reaction. [ABSTRACT FROM AUTHOR]

A two step one-pot sequence involving Ugi reaction followed by base promoted carbocyclization allows the synthesis of pyrrolopyridine (IV). [ABSTRACT FROM AUTHOR]

The synthesized 2-amino-1H-imidazole/triazole conjugates exhibit inhibitory activity against biofilms of S. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Microwave-Assisted Synthesis of 4H-Benzo[f]imidazo[1,4]diazepin-6-ones via a Post-Ugi Copper-Catalyzed Intramolecular Ullmann Coupling" by Z. Li and others, published in the journal "Tetrahedron Letters" in 2014.

An abstract of the article "FeCl3-Promoted Synthesis of 1,3,4-Thiadiazoles under Combined Microwave and Ultrasound Irradiation in Water" by Huangdi Feng, Xili Ying, Yanqing Peng, Erik V. Van der Eycken, Chuanduo Liu, Shanshan Zhao and Gonghua Song is presented.