Pd/C Catalyzed Cascade Synthesis of 2‐Arylquinazolinones from 2‐Iodoacetanilides Employing Ammonia and CO Precursors

Oxalic acid as a dual C1 surrogate for heterogeneous palladium-catalyzed tandem four-component quinazolinone synthesis

Herein, a heterogeneous Pd/C-catalyzed direct one-step four-component double carbonylative approach for cascade synthesis of 2-aryl quinazolinones has been reported for the first time starting from 2-iodoaniline derivatives and aryl iodides. The given reaction involves the simultaneous implementation of two different gaseous surrogates i.e., ammonium carbamate as an NH3 precursor and oxalic acid as a bi-functional reagent acting as a CO as well as a C-atom surrogate under ligand-free conditions.

Regioselective ortho halogenation of N-aryl amides and ureas via oxidative halodeboronation: harnessing boron reactivity for efficient C-halogen bond installation

The installation of the C-halogen bond at the ortho position of N-aryl amides and ureas represents a tool to prepare motifs that are ubiquitous in biologically active compounds. To construct such prevalent bonds, most methods require the use of precious metals and a multistep process. Here we report a novel protocol for the long-standing challenge of regioselective ortho halogenation of N-aryl amides and ureas using an oxidative halodeboronation. By harnessing the reactivity of boron over nitrogen, we merge carbonyl-directed borylation with consecutive halodeboronation, enabling the precise introduction of the C-X bond at the desired ortho position of N-aryl amides and ureas. This method offers an efficient, practical, and scalable solution for synthesizing halogenated N-heteroarenes under mild conditions, highlighting the superiority of boron reactivity in directing the regioselectivity of the reaction.

Supported Palladium-Catalyzed Tandem Synthesis of 2-(Alkylamino/amino)-3-arylquinazolin-4(3H)-ones Employing CO Source

Herein, we demonstrated heterogeneous and recyclable polystyrene-supported palladium (Pd@PS) nanoparticles (NPs) catalyzed tandem addition and intramolecular aminocarbonylative cyclization approach for the synthesis of potentially bioactive 2-(alkylamino/amino)-3-arylquinazolin-4(3H)-one analogues from 2-iodophenylcarbodiimides employing amines as nucleophiles and oxalic acid as an ex-situ CO alternative. Various cyclic/acyclic primary and secondary amines were employed and selectively produced substituted 2-(alkylamino)-3-arylquinazolin-4(3H)-ones in good to excellent yields. In addition, we extended the developed strategy to fix two ammonium carbamate and oxalic acid as gaseous NH₃ and CO sources respectively, for the synthesis of 2-amino-3-arylquinazolin-4(3H)-one derivatives. Furthermore, gram scale applicability, diverse substrate scope and high recyclability of the Pd@PS catalyst were the major achievements of the developed protocol.

Design, Synthesis and Biological Evaluation of Quinazolinamine Derivatives as Breast Cancer Resistance Protein and P-Glycoprotein Inhibitors with Improved Metabolic Stability

A series of twenty-two quinazolinamine derivatives showing potent inhibitory activities on breast cancer resistance protein (BCRP) and p-glycoprotein (P-gp) were synthesized. A cyclopropyl-containing quinazolinamine 22 was identified as a dual BCRP and P-gp inhibitor, while azide-containing quinazolinamine 33 showed BCRP inhibitory activity. These lead compounds were further investigated in a battery of mechanistic experiments. Compound 22 changed the localization of BCRP and P-gp in cells, thus inhibiting the efflux of anticancer drugs by the two ATP-binding cassette (ABC) transporters. In addition, both 22 and 33 significantly stimulated the ATP hydrolysis of the BCRP transporter, indicating that they can be competitive substrates of the BCRP transporter, and thereby increase the accumulation of mitoxantrone in BCRP-overexpressing H460/MX20 cells. Azide derivative 33, exhibited a greater inhibitory effect on BCRP after UV activation and can serve as a valuable probe for investigating the interactions of quinazolinamine derivatives with BCRP. Notably, the dual BCRP and P-gp inhibitors 4-5, 22-24, 27, and BCRP inhibitor 33 showed improved metabolic stability compared to Ko143.