TBHP as Methyl Source under Metal-Free Aerobic Conditions To Synthesize Quinazolin-4(3H )-ones and Quinazolines by Oxidative Amination of C(sp3 )-H Bond

A Systematic Review of Synthetic and Anticancer and Antimicrobial Activity of Quinazoline/Quinazolin-4-one Analogues

Quinazolines/quinazolin-4-ones are significant nitrogen-containing heterocycles that exist in various natural products and synthetic scaffolds with diverse medicinal and pharmacological applications. Researchers across the globe have explored numerous synthetic strategies to develop safer and more potent quinazoline/quinazolinone analogues, particularly for combating cancer and microbial infections. This review systematically examines scholarly efforts toward understanding this scaffold's synthetic pathways and medicinal relevance, emphasizing the role of metal and non-metal catalysts and other reagents in their synthesis. Additionally, the article discusses selected compounds' anticancer and antimicrobial properties, with a brief look into their structure-activity relationships.

One-pot Synthesis of 2,3-disubstituted-4(3H)-quinazolinone from o-aminobenzoic Acid and DMF Derivatives using Imidazole Hydrochloride as a Promoter

As a novel and environmentally friendly Brönsted acid, imidazole hydrochloride was used to promote the synthesis of 2,3-disubstituted-4(3H)-quinazolinone from o-aminobenzoic acid and DMF derivatives. The essence of this reaction is a multicomponent reaction, which constructs multiple chemical bonds between different components through the transamidation of imidazole hydrochloride. This protocol showed a wide range of functional group tolerance, and a series of quinazolinones were synthesized in low to moderate yields without metal catalysts, oxidants or other additives.

Switchable In Situ SO2 Capture and CF3 Migration of Enol Triflates with Peroxyl Compounds under Iron Catalysis

Switchable in situ SO₂ capture and CF₃ migration of enol triflates with peroxyl compounds under iron catalysis are presented. By regulating the structure of peroxides, a variety of keto-functionalized dialkyl sulfones and α-trifluoromethyl ketones were selectively synthesized in good yields under mild conditions.

Copper-Catalyzed Oxidative Cyclization of 2-Aminobenzamide Derivatives: Efficient Syntheses of Quinazolinones and Indazolones

A simple copper-catalyzed assembly to formulate quinazolinone and indazolone derivatives in a single protocol manner is reported. These transformations are based on the fact that DMF can serve as a reaction solvent and one carbon synthon for the construction of heterocyclic rings. Moreover, this protocol features base-free and Brønsted acid free environmentally benign conditions with broad synthetic scope. A good scalability is demonstrated.

I2/CuCl2-Copromoted Formal [4 + 1 + 1] Cyclization of Methyl Ketones, 2-Aminobenzonitriles, and Ammonium Acetate: Direct Access to 2-Acyl-4-aminoquinazolines

We herein report an I₂/CuCl₂-copromoted diamination of C(sp³)-H bonds for the preparation of 2-acyl-4-aminoquinazolines from methyl ketones, 2-aminobenzonitriles, and ammonium acetate. This reaction features operational simplicity, commercially available substrates, mild reaction conditions, and good functional group compatibility. Mechanistic studies indicate that CuCl₂ plays a pivotal role in this transformation. This study uses a methyl group as a novel input to construct 2-acyl-4-aminoquinazoline derivatives for the first time.

Photoinduced Enhanced Decomposition of TBHP: A Convenient and Greener Pathway for Aqueous Domino Synthesis of Quinazolinones and Quinoxalines

Catalyst-free photoinduced processes in aqueous medium represent significant advancement toward development of green and sustainable pathways in organic synthesis. tert-Butyl hydroperoxide (TBHP) is a widely used oxidant in organic reactions, where the decomposition of TBHP into its radicals by metal catalysts or other reagents is a key factor for efficient catalytic outcome. Herein, we report a simple and environmentally friendly visible light-promoted synthetic pathway for the synthesis of N-heterocyclic moieties, such as quinazolinones and quinoxalines, in the presence of TBHP as an oxidizing agent in aqueous medium that requires no catalysts/photocatalysts. The enhanced rate of decomposition to generate free radicals from TBHP upon visible light irradiation is the driving force for the domino reaction.

Electrosynthesis of Quinazolines and Quinazolinones via an Anodic Direct Oxidation C(sp3)-H Amination/C-N Cleavage of Tertiary Amine in Aqueous Medium

An electrochemical synthesis for quinazolines and quinazolinones was developed via a C(sp³)-H amination/C-N cleavage by virtue of the anodic oxidation. The reaction can be carried out in aqueous media under mild conditions to afford the desired products with high yields. The reaction mechanism was proposed after detailed investigation.

α-Hydroxy acid as an aldehyde surrogate: metal-free synthesis of pyrrolo[1,2-a]quinoxalines, quinazolinones, and other N-heterocycles via decarboxylative oxidative annulation reaction

A metal-free and efficient procedure for the synthesis of pyrrolo[1,2-a]quinoxalines, quinazolinones, and indolo[1,2-a]quinoxaline has been developed. The key features of our method include the in situ generation of aldehyde from α-hydroxy acid in the presence of TBHP (tert-butyl hydrogen peroxide), and further condensation with various amines, followed by intramolecular cyclization and subsequent oxidation to afford the corresponding quinoxalines, quinazolinones derivatives in moderate to high yields.

Phenazine Derivatives with Anti-Inflammatory Activity from the Deep-Sea Sediment-Derived Yeast-Like Fungus Cystobasidium laryngis IV17-028

Three new phenazine derivatives (1–3), along with known compounds (4–7) of saphenic acid derivatives, were isolated from a deep-sea sediment-derived yeast-like fungus Cystobasidium larynigs collected from the Indian Ocean. The structures of the new compounds (1–3) were determined by analysis of spectroscopic data, semi-synthesis and comparison of optical rotation values. All the isolated compounds (1–7), except for 2, showed nitric oxide (NO) production inhibitory effect against lipopolysaccharide (LPS)-induced murine macrophage RAW 264.7 cells without cytotoxicity at concentrations up to 30 μg/mL. This is the first report on the yeast-like fungus Cystobasidium laryngis producing phenazines and anti-inflammatory activity of 1–7 including saphenic acid (4).