Metal- and Oxidant-Free Synthesis of Quinazolinones from β-Ketoesters with o-Aminobenzamides via Phosphorous Acid-Catalyzed Cyclocondensation and Selective C–C Bond Cleavage

Cd-Based metal-organic frameworks from solvothermal reactions involving in situ aldimine condensation and the highly sensitive detection of Fe3+ ions

Four Cd(ii)-based compounds (1-4) were synthesized from solvothermal reactions involving the in situ aldimine condensation of an o-diamino-functionalized precursor 3,6-di(4H-imidazol-4-yl)benzene-1,2-diamine (L), Cd(NO₃)₂·4H₂O and aldehyde. Two modes of cycloaddition ([4 + 1] cycloaddition and [4 + 2] cycloaddition) occurred during condensation, causing the in situ generation of two benzimidazole derivative ligands (L1 and L3) and a quinoxaline derivative ligand (L2). Furthermore, the chemical selectivity of the condensation was studied, where the condensation of o-diamino and the aldehyde is more stable and easy to operate. This strategy enriches the synthesis method of MOFs. Additionally, compound 2 containing uncoordinated quinoxaline N atoms showed excellent luminescent sensitivity for Fe³⁺ detection.

Oxalic/malonic acids as carbon building blocks for benzazole, quinazoline and quinazolinone synthesis

Oxalic/malonic acids as CH/C₂H₃ carbon building blocks for the synthesis of 2-substituted and un-substituted benzazoles, quinazolines and quinazolinones.

One-pot regioselective synthesis of 2,4-disubstituted quinolines via copper(ii)-catalyzed cascade annulation

A copper(ii)-catalyzed cascade annulation for the one-pot synthesis of 2,4-disubstituted quinolines has been disclosed.

Brønsted acid-catalysed enantioselective construction of axially chiral arylquinazolinones

The axially chiral arylquinazolinone acts as a privileged structural scaffold, which is present in a large number of natural products and biologically active compounds as well as in chiral ligands. However, a direct catalytic enantioselective approach to access optically pure arylquinazolinones has been underexplored. Here we show a general and efficient approach to access enantiomerically pure arylquinazolinones in one-pot fashion catalysed by chiral phosphoric acids. A variety of axially chiral arylquinazolinones were obtained in high yields with good to excellent enantioselectivities under mild condition. Furthermore, we disclosed a method for atroposelective synthesis of alkyl-substituted arylquinazolinones involving Brønsted acid-catalysed carbon–carbon bond cleavage strategy. Finally, the asymmetric total synthesis of eupolyphagin bearing a cyclic arylquinazolinone skeleton was accomplished with an overall yield of 32% in six steps by utilizing the aforementioned methodology.

Axially chiral arylquinazolinones are structural motifs in several natural products and can also act as chiral ligands. Here, the authors show a chiral phosphoric acid-catalysed strategy to access enantiomerically pure arylquinazolinones by efficient transfer of central chirality into axial chirality.

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.

Synthesis of quinazolinones via radical cyclization of α-azidyl benzamides

Under visible light irradiation with N-bromosuccinimide, α-azidyl benzamides can be transformed into quinazolinones in high efficiency via cascade radical processes.

Efficient synthesis of pyrrolo[1,2-a]quinoxalines catalyzed by a Brønsted acid through cleavage of C-C bonds

An efficient and convenient one-pot domino reaction for the direct synthesis of pyrrolo[1,2-a]quinoxalines has been developed. This approach utilizes an imine formation reaction, SEAr reaction and cleavage of C-C bonds catalyzed by a Brønsted acid. β-Diketones and β-keto esters are both well tolerated to give the corresponding products in moderate to excellent yields.

Atmospheric CO2 promoted synthesis of N-containing heterocycles over B(C6F5)3 catalyst

CO₂ gas greatly promoted the cyclization of various o-substituted anilines with N,N-dimethylformamide, producing N-containing heterocycles in high yields.

Implications of dynamic imine chemistry for the sustainable synthesis of nitrogen heterocycles via transimination followed by intramolecular cyclisation

An application of dynamic imine chemistry to the sustainable synthesis of N-heterocycles from N-aryl benzylamines or imines and ortho-substituted anilines is described.

Synthesis of 2,3-dihydroquinazolinones and quinazolin-4(3H)-ones catalyzed by graphene oxide nanosheets in an aqueous medium: “on-water” synthesis accompanied by carbocatalysis and selective C–C bond cleavage

Graphene oxide nanosheet catalyzed strategies for construction of 2,3-dihydroquinazolinones and quinazolin-4(3H)-ones starting from anthranilamide and an aldehyde/ketone in aqueous medium at room temperature have been realized.

Sequential Michael addition/retro-Claisen condensation of aromatic β-diketones with α,β-unsaturated esters: an approach to obtain 1,5-ketoesters

A K₂CO₃-catalyzed one-pot protocol involving sequential C–C bond formation and cleavage of aromatic β-diketones with α,β-unsaturated esters is developed to obtain 1,5-ketoesters, proceeding smoothly under mild conditions in up to 98% isolated yield.

β-Ketophosphonates formation via deesterification or deamidation of cinnamyl/alkynyl carboxylates or amides with H-phosphonates

We report here an unprecedented Fe/Cu synergistically catalyzed deesterificative or deamidative oxyphosphorylation of unsaturated carboxylates or amides with H-phosphonates.