Iron-Catalyzed Cycloaddition of Amides and 2,3-Diaryl-2H-azirines To Access Oxazoles via C-N Bond Cleavage

Targeting hematological malignancies with isoxazole derivatives

Compounds with a heterocyclic isoxazole ring are well known for their diverse biologic activities encompassing antimicrobial, antipsychotic, immunosuppressive, antidiabetic and anticancer effects. Recent studies on hematological malignancies have also shown that some of the isoxazole-derived compounds feature encouraging cancer selectivity, low toxicity to normal cells and ability to overcome cancer drug resistance of conventional treatments. These characteristics are particularly promising because patients with hematological malignancies face poor clinical outcomes caused by cancer drug resistance or relapse of the disease. This review summarizes the knowledge on isoxazole-derived compounds toward hematological malignancies and provides clues on their mechanism(s) of action (apoptosis, cell cycle arrest, ROS production) and putative pharmacological targets (c-Myc, BET, ATR, FLT3, HSP90, CARM1, tubulin, PD-1/PD-L1, HDACs) wherever known.

An Accesss to 4,5,6-Trisubstituted Pyrimidines from 2H-Azirines and α-Isocyanoacetates or α-Isocyanoacetamides Enabled by 1,3-Dipolar [3 + 2] Cycloaddition/Ring-Expanding/Oxidative Aromatization Process

The products containing pyrimidine scaffolds exhibit various important physiological and biological activities. To date, the strategies to generate 4,5,6-trisubstituted pyrimidines were not reported. Here, a copper-catalyzed reaction of 2H-azirines with α-isocyanoacetates or α-isocyanoacetamides has been developed, rapidly preparing 4,5,6-trisubstituted pyrimidines. The mechanistic results reveal that this strategy underwent a formal 1, 3-dipolar [3 + 2] cycloaddition/ring-expanding/oxidative aromatization procedure to construct the desired pyrimidines.

DMF as an amine source: iron-catalyzed cyclization of 2H-azirines to imidazoles

A novel method has been developed for the synthesis of 1-methyl-4,5-diaryl-1H-imidazoles through Fe(II)-catalyzed cyclization of 2H-azirines and N,N-dimethylformamide (DMF) as an amine source. This transformation involves the cleavage of C-N and CN double bonds and the construction of new C-N and CN double bonds. The reaction has readily available starting materials, a wide range of substrates and mild reaction conditions. In addition, the reaction also facilitated the convenient synthesis of 1-methyl-2,4,5-triaryl-1H-imidazoles.

Synthesis of Flavanone and Quinazolinone Derivatives from the Ruthenium-Catalyzed Deaminative Coupling Reaction of 2'-Hydroxyaryl Ketones and 2-Aminobenzamides with Simple Amines

The cationic Ru-H complex [(C₆H₆)(PCy₃)(CO)RuH]⁺BF₄^- (1) with 3,4,5,6-tetrachloro-1,2-benzoquinone (L1) was found to be a highly effective catalyst for the deaminative coupling reaction of 2'-hydroxyaryl ketones with simple amines to form 3-substituted flavanone products. The analogous deaminative coupling reaction of 2-aminobenzamides with branched amines directly formed 3,3-disubstituted quinazolinone products. The catalytic method efficiently installs synthetically useful flavanone and quinazolinone core structures without employing any reactive reagents.