A NHC-Involved, Cascade, Metal-Free, and Three-Component Synthesis of 2,3-Diarylated Fully Substituted Furans under Solvent-Free Conditions
Contributors: Yu, Chenxia, Lu, Jun, Li, Tuanjie, Wang, Donglin, Qin, Binbin, Zhang, Honghong, Yao, Changsheng
... Abstract An efficient synthesis of 2,3-diarylated fully substituted furans was performed through the sequential reactions of Knoevenagel reaction, Stetter reaction catalyzed by NHC, and intramolecular cyclization under solvent-free conditions. The protocol has the advantages of easy workup, high yields, and an environmental benign procedure compared with the reported methods.
Contributors: Li, Feng, Wang, Zhong-Hua, Zhao, Lei, Chen, Fen-Er
... Abstract A facile and efficient enantioselective synthesis of florfenicol starting from commercially available 4-methylthiobenzaldehyde is described. Key features of the synthesis include a one-step oxidation of allyl and thioether groups in allylic alcohol to form (2S,3S)-epoxide under Sharpless epoxidation conditions and a highly efficient conversion of (1R,2R)-azide into amino alcohol via debenzylation and reduction of an azido moiety in one-pot operation.
Synthesis of 4-Oxoindeno[1,2-b]pyrroles through Copper-Catalyzed Tandem Reactions of 1-(2-Haloaryl)enones with Isocyanides
Contributors: Zhou, Fengtao, Fu, Liangbing, Wie, Jiajia, Ding, Ke, Cai, Qian
... Abstract Copper-catalyzed tandem reactions of 1-(2-haloaryl)-enones with isocyanides for the synthesis of 4-oxoindeno[1,2-b]pyrroles are described. Highly reactive cyclic organocopper intermediates are generated in the copper-catalyzed [3+2]-cycloaddition reactions of isocyanides to double or triple bonds. Successful intramolecular trapping of the organocopper intermediates led to the efficient formation of 4-oxoindeno[1,2-b]pyrroles.
Contributors: Zhu, Jianwei, Miao, Wenjun, Bao, Lingling, Ji, Tao, Tang, Guo, Xu, Pengxiang, Zhao, Yufen
... Abstract A mild and efficient method for the selective hydrolysis of 4-picolyl esters with magnesium in methanol or water in the presence of other esters and sensitive protecting groups is described. 4-Picolyl aryl ethers and thioethers are also smoothly deprotected to give the corresponding phenols and thiophenols.
Contributors: Appleton, Anthony L., Barlow, Stephen, Marder, Seth R., Hardcastle, Kenneth I., Bunz, Uwe H. F.
... Abstract We report the synthesis of the first N,N-dihydrotetraazaheptacene, which is solution-processible and stable as a solid under ambient conditions for over three years.
Contributors: Lu, Yongzhong, Wang, Ruiping, Qiao, Xixue, Shen, Zengming
... Abstract The copper-catalyzed C-H halogenation of 2-arylpyridines containing a variety of electron-withdrawing and electron-donating substituents was described. It is worth noting that cheap and easy-to-handle lithium halides were utilized as the halogen sources.
An Eficient One-Pot Synthesis of Macrocyclic Compounds Possessing Propargylamine Skeletons via Mannich Reaction
Contributors: Pang, Tao, Yang, Qinwan, Gao, Meng, Wang, Meng, Wu, Anxin
... Abstract A new efficient method using the Mannich three-component reaction in one pot to synthesize [1+2+1]- and [2+4+2]-macrocyclic compounds possessing a propargylamine backbone was reported. Interestingly, 1,4-diazepane as a multiuse reagent played the part of a substrate to participate in the Mannich reaction and acted as a base to promote the Eglinton-Glaser dimerizations in the coordination processes simultaneously via a one-pot procedure. The target macrocycles were obtained in good yields.
Potassium Carbonate Catalyzed Regioselective Aminohalogenation of β-Nitrostyrenes by Using Benzyl Carbamate/N-Chlorosuccinimide as a New Nitrogen/Chlorine Source
Contributors: Ji, Xiaoyun, Mei, Haibo, Qian, Yu, Han, Jianlin, Li, Guigen, Pan, Yi
... Abstract A combination of benzyl carbamate and N-chlorosuccinimide was developed as a new system for aminohalogenation of β-nitrostyrenes catalyzed by potassium carbonate in dichloromethane at room temperature. The reaction tolerates a wide range of substituents on the β-nitrostyrene, and proceeds smoothly in good-to-excellent chemical yields (77-99%). The new system shows a high efficiency and it markedly shortens the reaction time for aminochlorination. N,N-Dichlorobenzyl carbamate was also found to be a highly efficient source of both nitrogen and chlorine for the aminohalogenation reaction.
An Efficient Synthesis of 2-Aminofuran-3-carbonitriles via Cascade Stetter-γ-Ketonitrile Cyclization Reaction Catalyzed by N-Heterocyclic Carbene
Contributors: Liu, Peng, Lei, Min, Ma, Lei, Hu, Lihong
... Abstract An efficient method for the synthesis of 4,5-disubstituted 2-aminofuran-3-carbonitriles via a cascade Stetter-γ-ketonitrile cyclization reaction of aromatic aldehydes with acylidenemalononitriles, catalyzed by N-heterocyclic carbenes, has been developed. This procedure provides the corresponding products in moderate to high yields under mild conditions.
Microwave-Assisted One-Pot Synthesis of Pyrazolo[3,4-b]indoles and New Isoxazolo[5,4-b]indoles via Copper-Catalyzed Intramolecular C-N/C-O Bond Formation
Contributors: Kumar, Arepalli Sateesh, Rao, P. V. Amulya, Nagarajan, Rajagopal
... Abstract A facile one-pot, two-step synthesis of highly substituted pyrazolo[3,4-b]indoles and isoxazolo[5,4-b]indoles was developed via microwave-assisted, copper-catalyzed intramolecular heterocyclization (involving C-N/C-O bond formation) from 3-acetyl-2-chloroindoles in good to excellent yields.