3674-13-3Relevant articles and documents
A Metal-Free Domino Process for Regioselective Synthesis of 1,2,4-Trisubstituted Pyrroles: Application toward the Formal Synthesis of Ningalin B
Kumar, Virendra,Awasthi, Annapurna,Metya, Abhisek,Khan, Tabrez
, p. 11581 - 11595 (2019/10/02)
A new one-pot, transition-metal, acid/base-free domino process is developed for the regioselective synthesis of 1,2,4-trisubstituted pyrroles. The process involves 1,3-dipolar cycloaddition of unsymmetrical azomethine ylide resulting from the thermal C-C bond cleavage of unactivated aziridines with β-bromo-β-nitrostyrene, followed by a cascade of elimination and aromatization reaction sequence to preferentially furnish 1,2,4-trisubstituted pyrroles instead of the expected 1,2,3-trisubstituted pyrroles, in good to excellent yields. Further, the application of the methodology for the formal synthesis of ningalin B is delineated.
Diaziridyl Ether of Bisphenol A
Kang, Seohyun,Moon, Hyun Kyung,Yoon, Hyo Jae
, p. 4068 - 4076 (2018/06/19)
Increased complexities in applications involving curable materials virtually need new materials that can overcome the limitations of existing ones. Resins, the structure of which is based on bisphenol A backbone terminated with three membered N-heterocycles - aziridines - have been synthesized, and their thermal-curing performance in solution and solid state was evaluated by NMR and FT-IR spectroscopies, differential scanning calorimetry, and single lap shear strength test and compared with that of analogous epoxy resin (diglycidyl ether of bisphenol A; DGEBA). Results reveal that the chemical reactivity of the aziridine-based resins is fine-tunable by controlling the N-substituent of aziridine. These resins can undergo ring-opening polymerization in the presence of various curing agents under unprecedentedly mild conditions and show remarkably rapid curing rate, wide substrate scope, and excellent chemoselectivity as compared to the analogous epoxy resin. Our results demonstrate superb curing ability of aziridine, making it promising for applications in materials and polymer sciences.
Mesoporous silica-supported copper-catalysts for homocoupling reaction of terminal alkynes at room-temperature
Li, Hongling,Yang, Min,Zhang, Xia,Yan, Liang,Li, Jing,Qi, Yanxing
, p. 1343 - 1349 (2013/05/21)
Amine-functionalized mesoporous silica-supported copper catalysts SBA-15@amine-Cu and SBA-15@Oamine-Cu were prepared and proved to be efficient and reusable for homocoupling of terminal alkynes at room temperature with air as the oxidant. SBA-15@amine-Cu exhibited better recyclability than SBA-15@Oamine-Cu. The differences in the catalytic performances of the catalysts could be ascribed to catalyst structure and the interaction between copper and the supports. The as-prepared catalysts were systematically characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), high resolution-transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nitrogen physical adsorption. The analysis indicated that the mesoporous structure of the materials was retained during the immobilization process. XPS results suggested that the as-prepared catalysts were not obtained by a simple physical adsorption of CuCl on the supports. It is noted that, for aliphatic alkynes, the catalytic activity of SBA-15@amine-Cu is even higher than that of the homogeneous copper catalytic system and that of some previously reported heterogeneous systems.