129201-43-0Relevant academic research and scientific papers
Enantioselective Arylation of 3-Carboxamide Oxindoles with Quinone Monoimines and Synthesis of Chiral Spirooxindole-benzofuranones
Chen, Hui,Liu, Hui,Zhao, Si-Han,Cheng, Shao-Bing,Xu, Xiao-Ying,Yuan, Wei-Cheng,Zhang, Xiao-Mei
supporting information, p. 1067 - 1072 (2019/05/24)
A highly enantioselective arylation of 3-carboxamide oxoindoles with quinone monoimines is described. Various 3-aryl-3-carboxamide oxindoles with an all-carbon quaternary center were obtained in moderate to good yields (up to 99%) with moderate to good enantioselectivities (up to 98%) in the presence of a bifunctional thiourea-tertiary amine catalyst. The absolute configuration of one product was determined by an X-ray crystal structural analysis and the absolute configurations of the other products can be assigned by analogy. Moreover, several chiral spirooxindole-benzofuranones were synthesized from the 3-aryl-3-carboxamide oxindoles in moderate yields with moderate to good enantioselectivities.
Highly enantioselective [3+2] coupling of cyclic enamides with quinone monoimines promoted by a chiral phosphoric acid
Zhang, Minmin,Yu, Shuowen,Hu, Fangzhi,Liao, Yijun,Liao, Lihua,Xu, Xiaoying,Yuan, Weicheng,Zhang, Xiaomei
supporting information, p. 8757 - 8760 (2016/07/15)
Enantioselective [3+2] coupling of cyclic enamides with quinone monoimines was realised using a chiral phosphoric acid as a catalyst. This transformation allowed for the synthesis of highly enantioenriched polycyclic 2,3-dihydrobenzofurans (up to 99.9% ee). The absolute configuration of one product was determined by an X-ray crystal structural analysis. We also found a possible mechanism for this reaction.
Phenyliodine bis(trifluoroacetate) mediated intramolecular oxidative coupling of electron-rich N-phenyl benzamides
Yu, Zhengsen,Ma, Lijuan,Yu, Wei
supporting information; experimental part, p. 1534 - 1540 (2012/07/27)
The intramolecular oxidative C-O coupling of N-(4-alkoxy-phenyl) and N-(4-acetamido-phenyl) benzamides was achieved under metal-free conditions by using phenyliodine bis(trifluoroacetate) as oxidant and TMSOTf as catalyst. The reactions afford benzoxazole
Hydrohalogenation of N-acetyl(aroyl)-1,4-benzoquinone monoimines
Avdeenko,Konovalova,Ludchenko,Ledeneva,Vakulenko
experimental part, p. 214 - 229 (2011/05/05)
New N-acetyl-1,4-benzoquinone monoimines alkyl-substituted in the quinoid ring were synthesized. The hydrohalogenation of N-acetyl(aroyl)-1,4-benzoquinone monoimines proceeds exclusively in keeping with the 1,4-addition. The hydrochlorination occurs along the ionic mechanism, in the hydrobromination grows the role of the radical mechanism.
Synthesis of 5-substituted 2,3-dihydrobenzofurans in a one-pot oxidation/cyclization reaction
Baragona, Fabien,Lomberget, Thierry,Duchamp, Christian,Henriques, Natali,Lo Piccolo, Eugenio,Diana, Patrizia,Montalbano, Alessandra,Barret, Roland
experimental part, p. 8731 - 8739 (2011/12/02)
Variously substituted 2,3-dihydrobenzofurans have been synthesized according to a sequential one-pot oxidation/cyclization procedure between para-aminophenol derivatives and an azadiene.
Spectrophotometric and Titrimetric Determination of Carboxylic Acid Anhydrides
Verma, Krishna K.,Tyagi, Pramila
, p. 2157 - 2160 (2007/10/02)
Two redox methods are described for the determination of carboxylic acid anhydrides involving reaction with either an excess of 4-aminophenol or a measured but excessive amount of sulfanilamide and photometric titration of N-acyl-4-aminophenol with 2-iodylbenzoate by measuring the absorbance of orange-red product at 444 nm or the residual amount of sulfanilamide is determined by titration with chloramine-T in the presence of acidified potassium bromide using methyl red as visual indicator.Mixtures of certain anhydrides have also been analyzed by the 2-iodylbenzoate method.The methods are rapid, precise, and accurate.No correlation is needed if carboxylic and mineral acids are also present.Carboxylic acid chlorides also react quantitatively.
