86971-60-0Relevant articles and documents
Trisulfur-Radical-Anion-Triggered C(sp2)-H Amination of Electron-Deficient Alkenes
Nguyen, Khang X.,Nguyen, Thao T.,Nguyen, Tung T.,Pham, Hoai T. B.,Pham, Phuc H.,Phan, Nam T. S.,Wang, Haobin,Yang, Chou-Hsun
supporting information, p. 9751 - 9756 (2020/12/21)
A trisulfur-radical-anion (S3˙-)-triggered C(sp2)-H amination of α,β-unsaturated carbonyl derivatives with simple amines has been demonstrated. This protocol provides convenient access to a variety of synthetically valuable N-unprotected and secondary β-enaminones with absolute Z selectivity and tertiary β-enaminones with E selectivity. Mechanistic probe and electronic structure theory calculations suggest that S3˙- initiates the nucleophilic attacks via a thiirane intermediate.
Amido Complexes of Iridium with a PNP Pincer Ligand: Reactivity toward Alkynes and Hydroamination Catalysis
Hermosilla, Pablo,López, Pablo,García-Ordunìa, Pilar,Lahoz, Fernando J.,Polo, Víctor,Casado, Miguel A.
, p. 2618 - 2629 (2018/08/21)
The pincer ligand HN(CH2CH2PPh2)2 (1; PNHP) reacted with [{Ir(μ-X)(cod)}2] (X = Cl, OMe), affording complexes [fac-(PNHP)Ir(cod)]Cl (2) and [fac-(PNP)Ir(cod)] (3), respectively. The X-ray molecular structure of 2 showed that the PNP ligand coordinates in a facial fashion, with the N atom in an axial site and both P atoms coordinated in the equatorial plane. Compound 1 is able to protonate the hydroxo bridges in the complex [{Ir(μ-OH)(coe)2}2] forming the new amido complex [mer-(PNP)Ir(coe)] (4). Complex 4 is an extremely air sensitive compound, as confirmed by the isolation of the oxo complex [mer-(PNP)Ir(σ2-O2)] (8) from its interaction with air. Protonation of 4 with HBF4 afforded the corresponding amino complex [mer-(PNHP)Ir(coe)]BF4 (5), whose molecular structure enlightened by X-ray crystallography confirmed the PNP ligand to be coordinated in a meridional fashion. The coe ligand in 4 is tightly bonded to iridium; however, under an atmosphere of ethylene at 60 °C or with acrylonitrile at 70 °C complex 4 exchanges the olefin, affording compounds [mer-(PNP)Ir(σ2-C2H4)] (6) and [mer-(PNP)Ir(σ2-C2H3CN)] (7), respectively. Interaction of 4 with alkynes depends on the nature of the substrate; therefore, methyl phenylpropiolate reacted with 4, affording the adduct [mer-(PNP)Ir(σ2-PhCCC(O)OMe)] (9), while the parent acetylene undergoes a double C-H activation, affording the Ir(III) complex [fac-(PNHP)IrH(Ca‰?CH)2] (10). A DFT theoretical analysis of this transformation supports a metal-ligand cooperation mechanism. The reaction starts by deprotonation of an alkyne moiety by the PNP ligand followed by oxidative addition of the C-H bond to the metal of a second alkyne molecule. Additionally, we have tested complex 4 as a catalyst for the addition of gaseous ammonia to activated unsaturated substrates. A DFT theoretical analysis disclosed the operative mechanism on these organic transformations, which starts with a nucleophilic attack of ammonia to the bound alkyne, hydrogen migration to the metal, and reductive elimination steps.
Quinone-Fused Pyrazoles through 1,3-Dipolar Cycloadditions: Synthesis of Tricyclic Scaffolds and in vitro Cytotoxic Activity Evaluation on Glioblastoma Cancer Cells
Bertuzzi, Giulio,Crotti, Simone,Calandro, Pierpaolo,Bonini, Bianca Flavia,Monaco, Ilaria,Locatelli, Erica,Fochi, Mariafrancesca,Zani, Paolo,Strocchi, Elena,Mazzanti, Andrea,Chiariello, Mario,Franchini, Mauro Comes
, p. 1744 - 1750 (2018/09/11)
A novel and straightforward synthesis of highly substituted isoquinoline-5,8-dione fused tricyclic pyrazoles is reported. The key step of the synthetic sequence is a regioselective, Ag2CO3 promoted, 1,3-dipolar cycloaddition of C-heteroaryl-N-aryl nitrilimines and substituted isoquinoline-5,8-diones. The broad functional group tolerability and mild reaction conditions were found to be suitable for the preparation of a small library of compounds. These scaffolds were designed to interact with multiple biological residues, and two of them, after brief synthetic elaborations, were analyzed by molecular docking studies as potential anticancer drugs. In vitro studies confirmed the potent anticancer effects, showing promising IC50 values as low as 2.5 μm against three different glioblastoma cell lines. Their cytotoxic activity was finally positively correlated to their ability to inhibit PI3K/mTOR kinases, which are responsible for the regulation of diverse cellular processes in human cancer cells.
