122334-37-6Relevant articles and documents
A CO2-Catalyzed Transamidation Reaction
Yang, Yang,Liu, Jian,Kamounah, Fadhil S.,Ciancaleoni, Gianluca,Lee, Ji-Woong
, p. 16867 - 16881 (2021/11/18)
Transamidation reactions are often mediated by reactive substrates in the presence of overstoichiometric activating reagents and/or transition metal catalysts. Here we report the use of CO2as a traceless catalyst: in the presence of catalytic amounts of CO2, transamidation reactions were accelerated with primary, secondary, and tertiary amide donors. Various amine nucleophiles including amino acid derivatives were tolerated, showcasing the utility of transamidation in peptide modification and polymer degradation (e.g., Nylon-6,6). In particular,N,O-dimethylhydroxyl amides (Weinreb amides) displayed a distinct reactivity in the CO2-catalyzed transamidation versus a N2atmosphere. Comparative Hammett studies and kinetic analysis were conducted to elucidate the catalytic activation mechanism of molecular CO2, which was supported by DFT calculations. We attributed the positive effect of CO2in the transamidation reaction to the stabilization of tetrahedral intermediates by covalent binding to the electrophilic CO2
Rhoda-Electrocatalyzed Bimetallic C?H Oxygenation by Weak O-Coordination
Tan, Xuefeng,Massignan, Leonardo,Hou, Xiaoyan,Frey, Johanna,Oliveira, Jo?o C. A.,Hussain, Masoom Nasiha,Ackermann, Lutz
supporting information, p. 13264 - 13270 (2021/05/06)
Rhodium-electrocatalyzed arene C?H oxygenation by weakly O-coordinating amides and ketones have been established by bimetallic electrocatalysis. Likewise, diverse dihydrooxazinones were selectively accessed by the judicious choice of current, enabling twofold C?H functionalization. Detailed mechanistic studies by experiment, mass spectroscopy and cyclovoltammetric analysis provided support for an unprecedented electrooxidation-induced C?H activation by a bimetallic rhodium catalysis manifold.
Iron-Catalyzed, Iminyl Radical-Triggered Cascade 1,5-Hydrogen Atom Transfer/(5+2) or (5+1) Annulation: Oxime as a Five-Atom Assembling Unit
Chen, Ying-Chun,Du, Fei,Jiang, Kun,Liang, Wu,Ouyang, Qin,Shuai, Li,Wei, Ye,Yang, Jie
supporting information, p. 19222 - 19228 (2020/08/25)
By integration of iminyl radical-triggered 1,5-hydrogen atom transfer and (5+2) or (5+1) annulation processes, a series of structurally novel and interesting azepine and spiro-tetrahydropyridine derivatives have been successfully prepared in moderate to good yields. This method utilizes FeCl2 as the catalyst and readily available oximes as five-atom units, while showcasing broad substrate scope and good functional group compatibility. The annulation products can be easily converted into many valuable compounds. Moreover, DFT calculation studies are performed to provide some insights into the possible reaction mechanisms for the (5+2) and (5+1) annulations.