An iminophosphorane-based approach for the synthesis of spiropyrrolidine–imidazole derivatives

Reaction of Phosphines with 1-Azido-(2-halogenomethyl)benzene Giving Aminophosphonium-Substituted Indazoles

The reaction between a 1-azido-(2-halogenomethyl)benzene and a phosphine gives different products depending on the nature of the halogen, the phosphine itself, and the solvent employed. While PPh₃ (2 equiv) reacts with the chloro reagent in toluene to give the expected iminophosphorane-phosphonium adduct, trialkylphosphines (PCy₃ and PEt₃) surprisingly furnish an aminophosphonium substituted by a zwitterionic indazole. The bicyclic product can also form from PPh₃ using the bromo reagent in acetonitrile. A mechanism is proposed for this cyclization based on DFT calculations.

Unprecedented one-pot chemocontrolled entry to thioxoimidazolidinones and aminoimidazolones: synthesis of kinase inhibitor leucettamine B

A novel and highly chemoselective protocol for the construction of thioxoimidazolidinone and aminoimidazolone frameworks was explored, and the influence of the reaction conditions on product formation was studied to establish two distinct approaches for their selective formation. In this one-pot reaction, ambient temperature generally resulted in the formation of thioxoimidazolidinones, whereas microwave irradiation provided aminoimidazolones exclusively. An attempt to elucidate the observed chemoselectivity is described, and the products were confirmed by X-ray studies. One-pot synthesis toward Leucettamine B, a marine alkaloid, was achieved on the basis of this protocol.

Antitumor, antioxidant and antimicrobial studies of substituted pyridylguanidines

A series of N-pivaloyl-N′-(alkyl/aryl)-N″-pyridylguanidine of general formula C₄H₉CONHC(NR¹R²)NPy have been synthesized and characterized using elemental analysis, FT-IR, multinuclear NMR spectroscopy, and in the case of compounds 7 and 11, by single crystal X-ray diffraction (XRD). The synthesized guanidines were tested for antitumor activities against potato tumor, and showed excellent inhibition against Agrobacterium tumefaciens (AT10)-induced tumor. The antioxidant and antimicrobial activities of these new compounds against various bacterial and fungal strains were also investigated.