A convenient approach to 2,4-disubstituted quinazoline-3-oxides using active MnO2 as the oxidant

Using cheap, readily available, and economic active MnO2 as an oxidant, a series of 2,4-disubstituted quinazoline-3-oxides were synthesized in good to excellent yields by oxidation of the corresponding 1,2-dihydroquinazoline-3-oxides under mild conditions. This novel approach is simple and convenient and provides a series of 2,4-disubstituted quinazoline-3-oxides.

Rhodium-catalyzed regioselective ortho-allylation of 2,4-diarylquinazolines with allylic acetate

In this paper, a rhodium-catalyzed regioselective reaction of 2,4-diarylquinazolines with allylic acetate is described, leading to allylated quinazoline derivatives with high efficiency and good tolerance of functional groups. By switching to 2-arylquinazolin-4-ones, tandem C–H activation and aza-Michael addition are involved, leading to 1,6-dimethyl-5H-isoquinolino[1,2-b]quinazolin-8(6H)-one derivatives with high efficiency.

A concise construction of 4-alkynylquinazolines via [4 + 2] annulation of 4-alkynylbenzoxazinanones with acylhydroxamates under transition-metal-free conditions

A concise and highly efficient method for the construction of valuable 4-alkynylquinazolines under transition-metal-free conditions was developed via [4 + 2] annulation of 4-alkynylbenzoxazinanones with acylhydroxamates in good to excellent yields.

Copper-catalyzed cross-dehydrogenative coupling between quinazoline-3-oxides and indoles

A novel and simple protocol for the synthesis of 4-(indole-3-yl)quinazolines via cross-dehydrogenative coupling of quinazoline-3-oxides and indoles under an air atmosphere has been developed.

Direct C-4 alkylation of quinazoline N-oxides with ethers via an oxidative cross-coupling reaction under metal-free conditions

A novel and efficient protocol for the direct C-4 alkylation of quinazoline-3-oxides via radical oxidative coupling between quinazoline 3-oxides and ethers in the presence of TBHP was developed. The reaction proceeded smoothly under metal-free conditions, which provided quinazoline-containing heterocyclic molecules in moderate to good yields.

Rhodium-catalyzed C–H bond activation alkylation and cyclization of 2-arylquinazolin-4-ones

An efficient method for the synthesis of isoquinolino[1,2-b]quinazolin-8-one derivatives and 12-methyl-12H-isoindolo[1,2-b]quinazoline-10-one derivatives is described herein.

Rhodium-catalyzed malonation of 2-arylquinazolines with 2-diazomalonates: double C–H functionalization

Herein, rhodium-catalyzed malonation of 2-arylquinazolines with diazomalonates was described.

Synthesis of novel 1,5-disubstituted pyrrolo[1,2-a]quinazolines and their evaluation for anti-bacterial and anti-oxidant activities

A new series of 1,5-disubstituted pyrrolo[1,2-a]quinazoline derivatives were prepared from 2-chloro-4-substituted quinazolines, propargyl alcohol, and secondary amines through novel multi-component reactions.

Synthetic approaches, functionalization and therapeutic potential of quinazoline and quinazolinone skeletons: the advances continue

The presence of N-heterocycles as an essential structural motif in a variety of biologically active substances has stimulated the development of new strategies and technologies for their synthesis. Among the various N-heterocyclic scaffolds, quinazolines and quinazolinones form a privileged class of compounds with their diverse spectrum of therapeutic potential. The easy generation of complex molecular diversity through broadly applicable, cost-effective, practical and sustainable synthetic methods in a straightforward fashion along with the importance of these motifs in medicinal chemistry, received significant attention from researchers engaged in drug design and heterocyclic methodology development. In this perspective, the current review article is an effort to recapitulate recent developments in the eco-friendly and green procedures for the construction of highly challenging and potentially bioactive quinazoline and quinazolinone compounds in order to help medicinal chemists in designing and synthesizing novel and potent compounds for the treatment of different disorders. The key mechanistic insights for the synthesis of these heterocycles along with potential applications and manipulations of the products have also been conferred. This article also aims to highlight the promising future directions for the easy access to these frameworks in addition to the identification of more potent and specific products for numerous biological targets.

Advances in metal-catalyzed cross-coupling reactions of halogenated quinazolinones and their quinazoline derivatives

Halogenated quinazolinones and quinazolines are versatile synthetic intermediates for the metal-catalyzed carbon–carbon bond formation reactions such as the Kumada, Stille, Negishi, Sonogashira, Suzuki-Miyaura and Heck cross-coupling reactions or carbon-heteroatom bond formation via the Buchwald-Hartwig cross-coupling to yield novel polysubstituted derivatives. This review presents an overview of the application of these methods on halogenated quinazolin-4-ones and their quinazolines to generate novel polysubstituted derivatives.