26838-86-8Relevant articles and documents
Kinetic and mechanistic studies on quinuclidinolysis of Y-substituted-phenyl picolinates: Effect of amine nature on reactivity and transition- state structure
Um, Ik-Hwan,Kim, Min-Young,Kang, Yeseul
, p. 1405 - 1410 (2015)
Second-order rate constants (kN) have been measured spectrophotometrically for reactions of Y-substitutedphenyl picolinates (7a-7i) with a series of quinuclidines in 80 mol% H2O/20 mol% DMSO at 25.0 ± 0.1 °C. The Bronsted-type plot f
Copper-Catalyzed Electrochemical C-H Amination of Arenes with Secondary Amines
Yang, Qi-Liang,Wang, Xiang-Yang,Lu, Jia-Yan,Zhang, Li-Pu,Fang, Ping,Mei, Tian-Sheng
, p. 11487 - 11494 (2018/09/13)
Electrochemical oxidation represents an environmentally friendly solution to conventional methods that require caustic stoichiometric chemical oxidants. However, C-H functionalizations merging transition-metal catalysis and electrochemical techniques are, to date, largely confined to the use of precious metals and divided cells. Herein, we report the first examples of copper-catalyzed electrochemical C-H aminations of arenes at room temperature using undivided electrochemical cells, thereby providing a practical solution for the construction of arylamines. The use of n-Bu4NI as a redox mediator is crucial for this transformation. On the basis of mechanistic studies including kinetic profiles, isotope effects, cyclic voltammetric analyses, and radical inhibition experiments, the reaction appears to proceed via a single-electron-transfer (SET) process, and a high valent Cu(III) species is likely involved. These findings provide a new avenue for transition-metal-catalyzed electrochemical C-H functionalization reactions using redox mediators.
Mechanistic Insight into Weak Base-Catalyzed Generation of Carbon Monoxide from Phenyl Formate and Its Application to Catalytic Carbonylation at Room Temperature without Use of External Carbon Monoxide Gas
Konishi, Hideyuki,Matsubara, Mika,Mori, Keisuke,Tokiwa, Takaki,Arulmozhiraja, Sundaram,Yamamoto, Yuta,Ishikawa, Yoshinobu,Hashimoto, Hiroshi,Shigeta, Yasuteru,Tokiwa, Hiroaki,Manabe, Kei
supporting information, p. 3592 - 3601 (2017/10/24)
The mechanisms of the weak base-catalyzed generation of carbon monoxide (CO) and phenol from phenyl formate were investigated by experimental and theoretical methods. Kinetic studies revealed a first-order reaction in both phenyl formate and the base. The reaction was found to proceed by an E2 α-elimination pathway, which involves the abstraction of the formyl proton of phenyl formate, simultaneously generating CO and phenoxide. The reaction rate was affected by the substituents on phenyl formate, the polarity of solvents, and the basicity of bases. The mechanistic insight obtained from these studies permitted the chemical control of the rate of CO generation, which was the key to the development of the external CO-free Pd-catalyzed phenoxycarbonylation of haloarenes at room temperature. Because of the mild reaction conditions and wide substrate scope, this phenoxycarbonylation constitutes a general, safe, and practical method to synthesize arenecarboxylic acid esters. (Figure presented.).
