5346-21-4Relevant academic research and scientific papers
Enantioselective Synthesis of Azetidines through [3 + 1]-Cycloaddition of Donor-Acceptor Aziridines with Isocyanides
Zhang, Fengcai,Sang, Xinpeng,Zhou, Yuqiao,Cao, Weidi,Feng, Xiaoming
supporting information, p. 1513 - 1517 (2022/03/01)
The enantioselective [3 + 1]-cycloaddition of racemic donor-acceptor (D-A) aziridines with isocyanides was first realized under mild reaction conditions using a chiral N,N′-dioxide/MgIIcomplex as catalyst, providing a facile route to enantioenriched exo-imido azetidines with good to excellent yield (up to 99%) and enantioselectivity (up to 94% ee). An obvious chiral amplification effect was observed in this system, and an explanation was elucidated based on the experimental investigation and X-ray crystal structure of the enantiomerically pure catalyst.
4CzIPN-tBu-Catalyzed Proton-Coupled Electron Transfer for Photosynthesis of Phosphorylated N-Heteroaromatics
Liu, Yan,Chen, Xiao-Lan,Li, Xiao-Yun,Zhu, Shan-Shan,Li, Shi-Jun,Song, Yan,Qu, Ling-Bo,Yu, Bing
, p. 964 - 972 (2021/01/12)
2,4,5,6-Tetrakis(3,6-di-tert-butyl-9H-carbazol-9-yl)isophthalonitrile (4CzIPN-tBu) was developed as a photocatalyst for the phosphorus-radical-initiated cascade cyclization reaction of isocyanides. By using 4CzIPN-tBu as catalyst, we developed a visible-light-induced proton-coupled electron transfer strategy for the generation of phosphorus-centered radicals, via which a wide range of phosphorylated phenanthridines, quinolines, and benzothiazoles were successfully constructed.
Catalyst-free synthesis of phenanthridinesviaelectrochemical coupling of 2-isocyanobiphenyls and amines
Malviya, Bhanwar Kumar,Singh, Karandeep,Jaiswal, Pradeep K.,Karnatak, Manvika,Verma, Ved Prakash,Badsara, Satpal Singh,Sharma, Siddharth
, p. 6367 - 6378 (2021/04/16)
Catalyst free synthesis of 6-aryl phenanthridines and amides through an electrochemical reaction is reported in this study. The coupling reaction proceeds by the cathodic reduction ofin situformed diazonium ions, which are formed from anilines and an alkyl nitrite. The generated aryl radical diazonium ions coupled from isocyanides furnished the desired products in good yields. This cascade reaction was conducted in an undivided cell equipped with an RVC as the anode and Pt as the cathode usingnBu4NBF4as the electrolyte at room temperature. A series of detailed mechanistic studies have also been performed, including a radical clock experiment and cyclic voltammetry analysis.
Direct photoexcitation of benzothiazolines: Acyl radical generation and application to access heterocycles
He, Xiang-Kui,Li, Lei,Lu, Juan,Xuan, Jun,Ye, Hai-Bing
, (2021/11/27)
An acyl radical generation and functionalization strategy through direct photoexcitation of benzothiazolines has been developed. The formed acyl radical species can either be trapped by quinoxalin-2-ones to realize their C(3)-H functionalization or trigger a cascade radical cyclization with isonitriles to synthesise biologically important phenanthridines. The synthetic value of this protocol can be further illustrated by the modification of quinoxalin-2-ones, containing important natural products and drug-based complex molecules.
One-pot Cascade Reaction for the Synthesis of Phenanthridines via Suzuki Coupling/C?H Oxidation/Aromatization
Chen, Rener,Ding, Yuxin,Ma, Yongmin,Zhang, Yi
, p. 5697 - 5707 (2020/12/01)
A one-pot cascade coupling/annulation reaction for the synthesis of phenanthridines has been developed from arylboronic acids and o-bromo arylamides with DMSO as a carbon source. The desired phenanthridines were obtained in moderate to good yields by using simple procedure. (Figure presented.).
Copper promoted aerobic oxidative c(sp3)-c(sp3) bond cleavage of n-(2-(pyridin-2-yl)-ethyl)anilines
Yu, Yang,Zhang, Yong,Sun, Chengyu,Shi, Lei,Wang, Wei,Li, Hao
, p. 2725 - 2732 (2020/03/11)
A strategy of aerobic oxidative C(sp3)-C(sp3) bond cleavage of N-ethylaniline derivatives bearing azaarenes for the synthesis of N-aryl formamides has been developed. This approach was carried out smoothly with the CuI/TEMPO/air system to give N-aryl formamides in yields of 50-90%. With this methodology, a mutagenically active compound was constructed in 90% yield. Moreover, the reaction also provided a one-pot synthetic tool for accessing a promoter of hematopoietic stem cells by difunctionalization in 61% yield.
Photocatalytic xanthate-based radical addition/cyclization reaction sequence toward 2-biphenyl isocyanides: Synthesis of 6-alkylated phenanthridines
López-Mendoza, Pedro,Miranda, Luis D.
, p. 3487 - 3491 (2020/05/25)
A photocatalytic xanthate-based radical addition/cyclization reaction cascade toward 2-biphenylisocyanides is described as a practical and modular approach to 6-alkylated phenanthridines. The use of xanthates as radical precursors allowed the synthesis of diversely 6-substituted phenanthridines. Electrophilic radicals derived from nitriles, aromatic and aliphatic ketones, malonates, and amide derivatives, as well as radicals derived from phthalimidomethyl and benzylic derivatives were successfully introduced. The reaction proceeds under mild conditions without a stoichiometric amount of oxidant. Thirty novel phenanthridine scaffolds were synthesized with yields ranging from 24 to 76%.
Visible-Light-Driven Difluoromethylation of Isocyanides with S-(Difluoromethyl)diarylsulfonium Salt: Access to a Wide Variety of Difluoromethylated Phenanthridines and Isoquinolines
Chen, Jia-Yi,Li, Xin,Lin, Li-Ting,Liu, Guo-Kai,Qin, Wen-Bing,Wong, Henry N. C.,Xiong, Wei
, p. 10479 - 10487 (2020/09/23)
A highly efficient approach of visible-light-driven radical difluoromethylation of isocyanides to access a wide variety of difluoromethylated phenanthridines and isoquinolines is herein described. Electrophilic S-(difluoromethyl)diarylsulfonium salt proved to be a good difluoromethyl radical precursor under photoredox catalysis. A broad range of isocyanides were tolerated to furnish the corresponding difluoromethylated phenanthridines, isoquinolines, furo[3,2-c]pyridine, and pyrido[3,4-b]indole in moderate to excellent yields under mild conditions. A plausible mechanism was also proposed.
Additive-free radical cascade reaction of oxime esters: Synthesis of pyrroline-functionalized phenanthridines
Shao, Liming,Xue, Yijie,Xue, Dengqi,He, Qian,Ge, Qianwei,Li, Wei
, p. 12284 - 12293 (2020/11/10)
A variety of dihydropyrrole-functionalized phenanthridines were efficiently synthesized by the metal-free, radical cascade cyclization reaction of 2-isocyanobiphenyls with γ,δ- unsaturated oxime esters. The C-N/C-C/C-C bonds were formed via the oil bath method in a one-pot procedure with broad substrate applicability. The radical process was supported by kinetic isotope effect studies and radical inhibition studies.
Visible-Light-Induced Decarboxylative Cyclization/Hydrogenation Cascade Reaction to Access Phenanthridin-6-yl(aryl)methanol by an Electron Donor-Acceptor Complex
Shi, Wei,Ma, Fang,Li, Pinhua,Wang, Lei,Miao, Tao
, p. 13808 - 13817 (2020/11/20)
A novel and efficient visible-light-induced decarboxylative cyclization/hydrogenation cascade reaction of α-oxocarboxylic acids and 2-isocyanobiaryls has been developed. Without the need of any external photosensitizer, oxidant, and reductant, this method offers a mild and green approach for the synthesis of diverse alcohols in moderate to good yields. A mechanism indicated that an electron donor-acceptor complex-driven decarboxylation, radical addition/cyclization, and in situ photochemical reduction of ketones to alcohols could be involved in the reaction.
