39083-17-5Relevant academic research and scientific papers
Flow rhodaelectro-catalyzed alkyne annulations by versatile C-H Activation: Mechanistic support for rhodium(III/IV)
Kong, Wei-Jun,Finger, Lars H.,Messinis, Antonis M.,Kuniyil, Rositha,Oliveira, Jo?o C.A.,Ackermann, Lutz
supporting information, p. 17198 - 17206 (2019/10/28)
A flow-metallaelectro-catalyzed C-H activation was realized in terms of robust rhodaelectro-catalyzed alkyne annulations. To this end, a modular electro-flow cell with a porous graphite felt anode was designed to ensure efficient turnover. Thereby, a variety of C-H/N-H functionalizations proved amenable for alkyne annulations with high levels of regioselectivity and functional group tolerance, viable in both an inter- or intramolecular manner. The electro-flow C-H activation allowed easy scale up, while in-operando kinetic analysis was accomplished by online flow-NMR spectroscopy. Mechanistic studies suggest an oxidatively induced reductive elimination pathway on rhodium(III) in an electrocatalytic regime.
Alkali α-MnO2/Na: XMnO2 collaboratively catalyzed ammoxidation-Pinner tandem reaction of aldehydes
Jia, Xiuquan,Ma, Jiping,Wang, Min,Li, Xiaofang,Gao, Jin,Xu, Jie
, p. 7429 - 7436 (2016/10/21)
The tandem reaction is a growing field to yield important advances toward green and sustainable chemistry. Herein, we report a bifunctional manganese oxide catalyst with an interface binding redox phase (α-MnO2) and a basic phase (NaxMnO2). The molar ratio of NaOH/Mn plays a great role in the formation of α-MnO2/NaxMnO2. The sodium cation is essential for the formation of a basic NaxMnO2 phase while the potassium cation promotes the formation of a redox-active α-MnO2 phase. The interface structure of α-MnO2/NaxMnO2 geometrically favors the ammoxidation-Pinner tandem reaction to synthesize imidates in a 58-96% yield from aldehydes. Thus a phase collaborative effect is observed. In the ammoxidation process, the redox cycle of MnIV/MnIII is involved and the lattice oxygen in the α-MnO2 phase acts as an active oxygen species. The O-H in methanol is activated and dissociated on the basic sites of NaxMnO2 to the adsorbed methoxyl species to facilitate the Pinner synthesis. This approach bypasses the conventional synthesis of imidates, which suffer from harsh reaction conditions and the requirement for multiple steps.
Chichibabin-type condensation of cyclic ketones with 3-R-1,2,4-triazin-5(4 H)-ones
Egorov, Ilya N.,Tseitler, Tatyana A.,Kovalev, Igor S.,Slepukhin, Pavel A.,Rusinov, Vladimir L.,Chupakhin, Oleg N.
experimental part, p. 6007 - 6013 (2012/10/08)
Reactions between substituted 1,2,4-triazines and ketones were investigated. General procedures for one-pot synthesis of hydrogenated derivatives of such polycyclic systems as benzo[c][1,2,4]triazino[1,6-a][2] azecine, [1,2,4]triazino[1,6-f]phenantridine, and dicyclopenta[b,d]pyrido[1,2-f] [1,2,4]triazine are described.
The conversion of amides to esters with Meerwein's reagent. Application to the synthesis of a carfentanil precursor
Kiessling, Anthony J.,McClure, Cynthia K.
, p. 923 - 937 (2007/10/03)
An efficient two step transformation of 1°and 2°amides to methyl and ethyl esters has been developed using trimethyl- and triethyloxonium tetrafluoroborates, and dilute acid. This methodology was applied to 1-benzyl-4-phenylamino-4-piperidinecarboxamide, a precursor in the synthesis of carfentanil, to produce the methyl ester in 60% yield and the ethyl ester in 80% yield.
