939-62-8Relevant academic research and scientific papers
Ag(I)-Catalyzed C-H Carboxylation of Thiophene Derivatives
Lee, Mijung,Hwang, Young Kyu,Kwak, Jaesung
supporting information, p. 3136 - 3144 (2021/09/30)
CO2utilization is an attractive aspect as it allows the direct conversion of CO2into valuable chemicals. In this regard, direct incorporation of CO2into the C-H bond of heteroaromatic compounds is important due to the ubiquitous structural motifs of the heteroaromatic carboxylic acids. Herein, we report the Ag-catalyzed C-H carboxylation of thiophene derivatives. This new catalytic system involving a phosphine ligand and lithiumtert-butoxide enables the direct carboxylation of thiophenes under mild reaction conditions. Experimental studies revealed that the use oftert-butyl alkoxide is critical for the exergonic formation of an arylsilver intermediate, and the results were further supported by density functional theory calculations.
Desulfurization of Diaryl(heteroaryl) Sulfoxides with Benzyne
Chen, De-Li,Sun, Yan,Chen, Mengyuan,Li, Xiaojin,Zhang, Lei,Huang, Xin,Bai, Yihui,Luo, Fang,Peng, Bo
supporting information, (2019/06/13)
Two benzyne-enabled desulfurization reactions have been demonstrated which convert diaryl sulfoxides and heteroaryl sulfoxides to biaryls and desulfurized heteroarenes, respectively. The reaction accessing biaryls tolerates a variety of functional groups, such as halides, pseudohalides, and carbonyls. Mechanistic studies reveal that both reactions proceed via a common assembly process but divergent disassemblies of the generated tetraaryl(heteroaryl) sulfuranes.
An efficient method for the preparation of: Tert -butyl esters from benzyl cyanide and tert -butyl hydroperoxide under the metal free condition
Chen, Xiuling,Li, Yan,Wu, Minghu,Guo, Haibing,Jiang, Longqiang,Wang, Jian,Sun, Shaofa
, p. 102023 - 102027 (2016/11/09)
A novel protocol to synthesize tert-butyl esters from benzyl cyanides and tert-butyl hydroperoxide has been successfully achieved. In the presence of tert-butyl hydroperoxide, Csp3-H bond oxidation, C-CN bond cleavage and C-O bond formation proceeded smoothly in one pot under the metal-free condition.
Intramolecular rearrangement of α-azidoperoxides: An efficient synthesis of tert-butyl esters
Pramanik, Suman,Reddy, Reddy Rajasekhar,Ghorai, Prasanta
, p. 1393 - 1396 (2015/03/30)
An unprecedented intramolecular rearrangement of α-azidoperoxides, promoted by simple organic base to provide tert-butyl esters, has been presented. Further, a one-pot methodology consisting of in situ generation of the α-azidoperoxides from corresponding aldehydes followed by base-promoted rearrangement to obtain the desired ester has also been executed. Relevant mechanistic studies, to provide the proof for intramolecular alkoxy transfer, are investigated.
A mesoporous organosilica grafted Pd catalyst (MOG-Pd) for efficient base free and phosphine free synthesis of tertiary butyl esters via tertiary-butoxycarbonylation of boronic acid derivatives without using carbon monoxide
Ghosh, Kajari,Molla, Rostam Ali,Iqubal, Md. Asif,Islam
, p. 3540 - 3551 (2015/06/25)
A mesoporous organosilica grafted palladium(ii) catalyst was synthesized and characterized using various spectroscopic techniques. Its catalytic activity was evaluated for the synthesis of tertiary butyl esters via tert-butoxycarbonylation of boronic acid
Copper-catalyzed oxidative esterification of aldehydes with dialkyl peroxides: Efficient synthesis of esters of tertiary alcohols
Zhu, Yefeng,Wei, Yunyang
, p. 13668 - 13670 (2013/08/23)
Copper-catalyzed oxidative esterification of aldehydes with dialkyl peroxides has been developed. This protocol affords a novel approach for the synthesis of carboxylic esters of tertiary alcohols under mild conditions. Depending on the catalyst system, a variety of tertiary esters were produced in good to excellent yields.
An efficient method for the preparation of tertiary esters by palladium-catalyzed alkoxycarbonylation of aryl bromides
Xin, Zhuo,Gogsig, Thomas M.,Lindhardt, Anders T.,Skrydstrup, Troels
supporting information; experimental part, p. 284 - 287 (2012/02/16)
The palladium-catalyzed alkoxycarbonylation of aryl bromides is described for the efficient preparation of tertiary esters. The protocol proved compatible with a wide variety of functionalized (hetero)aromatic bromides, as well as several different sterically hindered tertiary alcohols, affording the alkoxycarbonylated products in high yields. Finally, the formation of aromatic trityl esters is discussed.
GAS-PHASE PYROLYTIC REACTIONS. PART 3. HAMMETT ρ CONSTANTS OF GAS-PHASE ELIMINATIONS OF ALKYLARYLCARBOXYLATE AND ETHANOATE ESTERS AND THEIR CORRELATION WITH SUBSTRATE MOLECULAR FRAMEWORK
Al-Awadi, Nouria A.,Al-Bashir, Rasha F.,ElDusouqui, Osman M. E.
, p. 2903 - 2910 (2007/10/02)
The kinetics of the gas-phase thermal elimination of seven tert-butyl (hetero)arylcarboxylate esters (GCO2But) were measured over a temperature range 50 K; the groups were the phenyl, 3- and 4-pyridyl, 2- and 3-furyl, and 2- and 3-thienyl moieties.The reactions were homogeneous and unimolecular with log A/s-1 scaling 12.45 +/- 0.44, and with an entropy of activation uniformly negative and small.The kinetics obeyed a first-order rate equation, and at 600 K the rate coefficients (103k/s-1) of the esters, in the order given above, were: 54.1, 85.3, 120.5, 76.9, 43.2, 86.3 and 46.1, respectively.Hammett correlation of the present kinetic data with the literature ρ0 - values of the given substituents gave a reaction ρ constant compatible with the ethanoate molecular frame rather than with the carboxylate structure.The physical constants of five new t-butyl heteroarylcarboxylate esters are also described.
