Copper-Catalyzed Domino Reaction Involving C-C Bond Cleavage To Construct 2-Aryl Quinazolinones

Electrochemically induced synthesis of quinazolinones via cathode hydration of o-aminobenzonitriles in aqueous solutions

An efficient and practical electrochemically catalyzed transition metal-free process for the synthesis of substituted quinazolinones from simple and readily available o-aminobenzonitriles and aldehydes in water has been accomplished. I₂/base and water play an unprecedented and vital role in the reaction. By electrochemically catalysed hydrolysis of o-aminobenzonitriles, the synthesis of quinazolinones with benzaldehyde was first proposed. The synthetic utility of this method was demonstrated by gram-scale operation, as well as the preparation of bioactive N-(2,5-dichlorophenyl)-6-(2,2,2-trifluoroethoxy) pteridin-4-amine, which enables straightforward, practical and environmentally benign quinazolinone formation.

Synthesis of quinazolin-4(1H)-ones via amination and annulation of amidines and benzamides

Quinazolinones have broad applications in the biological, pharmaceutical and material fields. Studies on the synthesis of these compounds are therefore widely conducted. Herein, a novel and highly efficient copper-mediated tandem C(sp2)-H amination and annulation of benzamides and amidines for the synthesis of quinazolin-4(1H)-ones is proposed. This synthetic route can be useful for the construction of quinazolin-4(1H)-one frameworks.

Bismuth-Catalyzed Synthesis of 2-Substituted Quinazolinones

The bismuth-catalyzed oxidative condensation of aldehydes with 2-aminobenzamide under aerobic conditions is reported using ethanol as the solvent. Good to excellent isolated yields (68-95%) of the corresponding 2-substituted quinazolinones were obtained under mild reaction conditions with excellent functional group tolerance. The quinazolinones were further functionalized to afford N-allylated quinazolinones, 2-aminopyridine derivatives, and annulated polyheterocyclic compounds via transition-metal catalyzed reactions.

Autoxidation of Heterocyclic Aminals

The autoxidation reactions of 2-acyl-2,3-dihydroquinazolin-4(1H)-ones 4a and 5a and 2,2'-bis(dihydroquinazolinone) 6a are described. These reactions generate aminyl radicals that undergo β-C-C cleavage, and subsequent reactions of the resulting C-based radicals with O₂ lead to diverse products with good selectivity, depending on the structure of the substrate. Oxidation of 4a, in which the 2-acyl group is part of a cyclic acenaphthenone unit, yields a heterocyclic C-hydroperoxylaminal via 1,2-acyl migration. Oxidation of 5a, which contains a 2-acetyl group, yields peracetic acid and a quinazolinone product. Oxidation of 6a forms a bis(quinazolinone) by net dehydrogenation.

A copper-catalyzed Ritter-type cascade via iminoketene for the synthesis of quinazolin-4(3H)-ones and diazocines

We have developed a copper-catalyzed Ritter-type reaction/cyclization cascade of anthranilic acids and nitriles, affording the quinazolin-4(3H)-ones and diazocines.

Iron-catalyzed aerobic oxidative cleavage of the C–C σ-bond using air as the oxidant: chemoselective synthesis of carbon chain-shortened aldehydes, ketones and 1,2-dicarbonyl compounds

An efficient iron-catalyzed aerobic oxidative cleavage of the C–C bond to generate a number of carbon-shortened carbonyl compounds.

Metal-free synthesis of quinazolinones without any additives in water

Here we report that an excess amount of aldehyde, in particular, aliphatic aldehyde, without any additives, efficiently facilitates the oxidation of aminal intermediates to quinazolinones in pure water.

A copper catalyzed multicomponent cascade redox reaction for the synthesis of quinazolinones

A copper catalyzed multicomponent cascade redox reaction for the synthesis of various quinazolinones starting from easily available 2-bromobenzamides, benzylic alcohols and sodium azide as a nitrogen source has been developed.

Ligand-free Pd-catalyzed and copper-assisted C-H arylation of quinazolin-4-ones with aryl iodides under microwave heating

A microwave-assisted method for the palladium-catalyzed direct arylation of quinazolin-4-one has been developed under copper-assistance. This method is applicable to a wide range of aryl iodides and substituted (2H)-quinazolin-4-ones. This protocol provides a simple and efficient way to synthesize biologically relevant 2-arylquinazolin-4-one backbones.

Copper-catalyzed tandem N-arylation/condensation: synthesis of quinazolin-4(3H)-ones from 2-halobenzonitriles and amides

A novel, straightforward and practical copper-catalyzed domino protocol for synthesis of quinazolin-4(3H)-one derivatives from commercially available 2-halobenzonitriles and amides was successfully developed.

Rapid assembly of quinazolinone scaffold via copper-catalyzed tandem reaction of 2-bromobenzamides with aldehydes and aqueous ammonia: application to the synthesis of the alkaloid tryptanthrin

An efficient synthesis of quinazolinones via copper-catalyzed tandem reaction of 2-bromobenzamides with aldehydes and aqueous ammonia has been developed.