29670-64-2Relevant academic research and scientific papers
RING CLEAVAGE AND RING EXPANSION OF INDOLES BY SUPEROXYDE ION
Balogh-Hergovich, E.,Speier, G.
, p. 4473 - 4476 (1982)
The reaction of indoles (1) with superoxide ion resulted in ring cleavage to give o-formyl and o-acylaminoketones (6) or N-acylanthranilic acid (8) and ring expansion yielding 2-quinolones (7).All reactions are chemiluminescent except that of 2-methylindole (1h), which gave a coupled product (9).
Oxidative Cleavage of Indoles Mediated by Urea Hydrogen Peroxide or H2O2 in Polar Solvents
Llopis, Natalia,Gisbert, Patricia,Baeza, Alejandro
supporting information, p. 3245 - 3249 (2021/06/08)
The oxidative cleavage of indoles (Witkop oxidation) involving the use of H2O2 or urea hydrogen peroxide in combination with a polar solvent has been described. Among these solvents, 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) stands out as the one affording the corresponding 2-ketoacetanilides generally in higher yields The protocol described has also enabled the oxidation of different pyrroles and furans derivatives. Furthermore, the procedure was implemented in a larger-scale and HFIP was distilled from the reaction mixture and reused (up to 4 cycles) without a significant detriment in the reaction outcome, which remarks its sustainability and applicability. (Figure presented.).
N-Heterocyclic Carbene/Cobalt Cooperative Catalysis for the Chemo- and Regioselective C?N Bond Formation between Aldehyde and Amines/Amides
Siddiqui, Asher M.,Khalid, Anam,Khan, Arif,Azad, Chandra S.,Samim, Mohd.,Khan, Imran A.
, p. 4281 - 4287 (2020/07/24)
A novel methodology for the construction of various secondary (4 examples), tertiary amides (31 examples), and imides (16 examples) by a Cobalt(II) catalyzed oxidative amide coupling in aqueous media. The Co(III)-TMC was reacted with N-Heteroatom Carbene to form active catalyst Co(II)NHC-TMC in situ which involves in the coordination with Breslow's intermediate and SET for the activation of aldehyde and amides. The mechanism for activation of amide and amine differs on the basis of SET based nucleophilic addition and ligand exchange respectively. The regeneration of the catalyst was achieved using Fe(III)(EDTA)-H2O2 as oxidant. The use of Co(II)TMC-O2 was also found equally efficient in the process. The method is found regioselective for N?H activation in the presence of equally susceptible ortho-C?H bond activation. And amines were found more susceptible then the corresponding amide for the reaction.
Transition-Metal-Free Synthesis of Acridones via Base-Mediated Intramolecular Oxidative C?H Amination
Wei, Wen-Tao,Sheng, Jian-Fei,Miao, Hui,Luo, Xiang,Song, Xian-Heng,Yan, Ming,Zou, Yong
supporting information, p. 2101 - 2106 (2018/06/14)
Intramolecular oxidative C?H amination of 2-aminobenzophenones was achieved in the presence of potassium tert-butoxide and dimethyl sulfoxide. A series of functionalized acridones were prepared in moderate to excellent yields in a mild, efficient, and transition-metal-free manner. (Figure presented.).
Synthesis of Aryl Ketoamides via Aryne Insertion into Imides
Wright, Austin C.,Haley, Christopher K.,Lapointe, Guillaume,Stoltz, Brian M.
supporting information, p. 2793 - 2795 (2016/07/06)
An insertion of arenes into both imides and anhydrides via reactive aryne intermediates is presented. The reaction is performed under exceptionally mild conditions, and the corresponding ketoamide products are amenable to derivatization to deliver a variety of synthetically useful motifs such as quinolones, indoles, and ketoanilines.
Efficient Friedel–Crafts benzoylation of aniline derivatives with 4-fluorobenzoyl chloride using copper triflate in the synthesis of aminobenzophenones
Tran, Phuong Hoang,Phung, Huy Quang,Hansen, Poul Erik,Tran, Hai Ngoc,Le, Thach Ngoc
, p. 893 - 901 (2016/07/06)
ABSTRACT: An efficient pathway for the synthesis of the aminobenzophenone derivatives via Friedel–Crafts benzoylation using copper triflate as catalyst is proposed. New derivatives are synthesized. The copper triflate could be easily recovered and reused without loss of catalytic activity. Both the use of ionic liquids and microwave heating turned out to be fruitful.
Potassium iodide-catalyzed three-component synthesis of 2-arylquinazolines via amination of benzylic C-H bonds of methylarenes
Zhao, Dan,Shen, Qi,Li, Jian-Xin
supporting information, p. 339 - 344 (2015/03/04)
A novel potassium iodide-catalyzed three-component synthesis of quinazolines via benzylic C-H bonds amination was developed. Commonly used ammonia salt and the sp3 carbon in commercially available methylarenes were used as nitrogen and C1 sources, respectively. Mechanistic studies indicated that an aryl aldehyde is involved as a key intermediate in the reaction.
Application of H/D exchange to hydrogen bonding in small molecules
Schneider, Tanya L.,Halloran, Kevin T.,Hillner, Julie A.,Conry, Rebecca R.,Linton, Brian R.
supporting information, p. 15101 - 15104 (2013/11/06)
Do you recognize me? A series of simple amides has been used to demonstrate the application of hydrogen/deuterium exchange in small-molecule hydrogen bonding. By comparison with similar controls, the degree of protection from H/D exchange can provide insight into the degree of hydrogen bonding (see scheme).
Palladium-catalyzed direct oxidative ortho-acylation of anilides with toluene derivatives
Weng, Jianquan,Yu, Zhiqin,Liu, Xinghai,Zhang, Guofu
supporting information, p. 1205 - 1207 (2013/03/13)
Direct oxidative ortho-acylation reaction of anilides with toluene derivatives in the presence of palladium acetate using tert-butyl hydroperoxide as an oxidant was developed. A broad range of diaryl ketones was obtained in good to excellent yields (up to 95%). The plausible mechanism was also proposed.
Palladium-catalyzed direct ortho -acylation through an oxidative coupling of acetanilides with toluene derivatives
Yin, Zhangwei,Sun, Peipei
, p. 11339 - 11344 (2013/02/23)
A facile ortho-acylation of acetanilides by a Pd-catalyzed oxidative C-H activation was developed in which low toxic, stable, and commercially available toluene derivatives were first used as acylation reagents by a tandem reaction to form o-acylacetanili
