7022-47-1Relevant academic research and scientific papers
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.
KMnO4-mediated oxidative C[sbnd]N bond cleavage of tertiary amines: Synthesis of amides and sulfonamides
Zhang, Zhang,Liu, Yong-Hong,Zhang, Xi,Wang, Xi-Cun
, p. 2763 - 2770 (2019/04/10)
KMnO4-mediated oxidative C[sbnd]N bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.
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.
NBu4NI-catalyzed oxidative amidation of aldehydes with tertiary amines
Wang, Shan,Wang, Jian,Guo, Rui,Wang, Gao,Chen, Shan-Yong,Yu, Xiao-Qi
supporting information, p. 6233 - 6236 (2013/10/22)
An efficient oxidative coupling protocol for amide formation has been developed. Various tertiary amines and aromatic aldehydes were oxidized to their corresponding tertiary amides in moderate to good yields in the presence of a simple nBu4NI-catalyst.
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
Photocyclization of Aryl Halides. Part 3. Phenanthridone Photosynthesis from 2-Halogenobenzanilides
Grimshaw, James,Silva, A. Prasanna de
, p. 857 - 866 (2007/10/02)
2-Chlorobenzanilides cyclize to phenanthridones in deaereted cyclohexane solution on 254 nm irradiation, whereas 2-bromo- and 2-iodo-benzanilides undergo dehalogenative reduction.These observations are understandable in terms of the assisted homolysis model as applied to configurationally flexible molecules.Cyclization in hydrocarbon media is retarted by triplet quenchers and fails in polar solvents.The cyclization can also be singlet and triplet sensitized. 4'-Substituents influence the cyclization quantum yield by altering the ?-donor ability of the aniline ring and the rotational barrier about the amide bond.
