7022-47-1Relevant articles and documents
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.
Microwave assisted synthesis of phenanthridinones and dihydrophenanthridines by vasicine/KO: T Bu promoted intramolecular C-H arylation
Sharma, Sushila,Kumar, Manoranjan,Sharma, Shruti,Nayal, Onkar S.,Kumar, Neeraj,Singh, Bikram,Sharma, Upendra
, p. 8536 - 8544 (2016/09/28)
A simple, efficient, rapid and transition metal-free methodology has been developed by utilizing vasicine (a natural product), as a catalyst for the synthesis of phenanthridinones and dihydrophenanthridines. The reaction proceeds through intramolecular C-H arylation with aryl halides in the presence of KOtBu as a base under microwave irradiation in sulfolane as a solvent. The reaction proceeds well with various aryl iodides, bromides and more remarkably with less reactive aryl chlorides for 15 minutes, providing the corresponding products in 45-90% yields.
Direct arylation under catalysis of an oxime-derived palladacycle: Search for a phosphane-free method
Zhang, Guofu,Zhao, Xiaobao,Yan, Yunbing,Ding, Chengrong
, p. 669 - 672 (2012/03/27)
A phosphane-free method for the direct arylation of benzothiazole by employing oxime-derived palladacycle 1 as a catalyst was developed. The new catalyst system can be used for 2-arylations by using aryl bromides and iodides. In addition, this method is especially suitable for the intramolecular direct coupling of bromo-and iodoamides, as well aschloroamides, to achieve a rapid synthesis of benzo[c]phenanthridine alkaloids. Direct arylation reactions under catalysis of an oxime-derived palladacycle were investigated. This phosphane-free method is applicable for the 2-arylation of benzothiazole and is especially suitable for the intramolecular direct coupling of bromo-and iodoamides, as well as chloroamides, to achieve rapid synthesis of benzo[c]phenanthridine alkaloids. Copyright