189575-70-0Relevant academic research and scientific papers
Reductive Coupling of Aryl Halides via C—H Activation of Indene
Zhang, Bo-Sheng,Yang, Ying-Hui,Wang, Fan,Gou, Xue-Ya,Wang, Xi-Cun,Liang, Yong-Min,Li, Yuke,Quan, Zheng-Jun
, p. 1573 - 1579 (2021/05/28)
This paper describes the first case of a reductive coupling reaction with indene, a non-heteroatom olefin used as a reducing agent. The scope of the substrate is wide. The homo-coupling, cross-coupling, and synthesis of 12 and 14-membered rings were realized. The control experiment, indene-product curve and density functional theory calculations showed that the η3-palladium indene intermediate was formed by C—H activation in the presence of cesium carbonate. We speculate that the final product was obtained through a Pd (IV) intermediate or aryl ligand exchange. In addition, we excluded the formation of palladium anion (Pd(0)?) intermediates.
Modular Tandem Mizoroki-Heck/Reductive Heck Reactions to Construct Fluorenes from Cyclic Diaryliodoniums
Peng, Xiaopeng,Yang, Yang,Luo, Bingling,Wen, Shijun,Huang, Peng
supporting information, p. 222 - 226 (2020/12/01)
Starting from cyclic diaryliodoniums and terminal alkenes, a diverse set of fluorenes is conveniently constructed. The reactions catalyzed by palladium undergo one conventional Mizoroki-Heck reaction and one reductive Heck reaction. The scope of alkenes is general, leading to 29 fluorenes which would expand the structural diversity of fluorene reservoir. (Figure presented.).
Palladium-Catalyzed C-H Amination/[2 + 3] or [2 + 4] Cyclization via C(sp3or sp2)-H Activation
An, Yang,Ding, Ya-Nan,Gou, Xue-Ya,Li, Qiao,Li, Yuke,Liang, Yong-Min,Zhang, Xiao-Yan,Zhang, Zhe
supporting information, p. 7961 - 7965 (2021/10/25)
This report describes a palladium-catalyzed Catellani reaction consisting of amination/[2 + 3] or [2 + 4] cyclization via a carboxylate ligand-exchange strategy. This method effectively activates ortho-substituents that avoid a second C-H palladation. The scope of substrates was broad, o-methyl-substituted iodoarenes were applied to the reaction smoothly, and o-phenyl-substituted iodoarenes can also be obtained by this method. In terms of mechanism, density functional theory calculations proved the sequence of the key five-membered aryl-norbornene-palladacycle intermediate formation and C(sp3 or sp2)-H activation.
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
supporting information, 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.
Scalable electrochemical synthesis of diaryliodonium salts
Elsherbini, Mohamed,Moran, Wesley J.
supporting information, p. 4706 - 4711 (2021/06/11)
Cyclic and acyclic diaryliodonium are synthesised by anodic oxidation of iodobiaryls and iodoarene/arene mixtures, respectively, in a simple undivided electrolysis cell in MeCN-HFIP-TfOH without any added electrolyte salts. This atom efficient process does not require chemical oxidants and generates no chemical waste. More than 30 cyclic and acyclic diaryliodonium salts with different substitution patterns were prepared in very good to excellent yields. The reaction was scaled-up to 10 mmol scale giving more than four grams of dibenzo[b,d]iodol-5-ium trifluoromethanesulfonate (>95%) in less than three hours. The solvent mixture of the large-scale experiment was recovered (>97%) and recycled several times without significant reduction in yield.
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.
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.
Cobalt(II)-Catalyzed [5+2] C?H Annulation of o-Arylanilines with Alkynes: An Expedient Route to Dibenzo-[b,d]azepines
Ling, Fei,Xie, Zhen,Chen, Jiachen,Ai, Chongren,Shen, Haiwei,Wang, Ze,Yi, Xiao,Zhong, Weihui
supporting information, p. 3094 - 3101 (2019/05/21)
The first example of CoCl2-catalyzed formal [5+2] oxidative annulation of o-arylanilines with alkynes was developed, giving access to various important imine-containing dibenzo-[b,d]azepine scaffolds through sequential C?C/C?N bond formation. The reaction employs catalytic amount of manganese and oxygen as cooxidants, and features a broad substrate scope. Preliminary mechanistic studies suggested that C?H activation is involved in the rate-determining step. Moreover, both internal and terminal alkynes are well tolerated in this transformation. Besides, a regioselective migratory insertion was observed when using terminal alkynes as substrates. (Figure presented.).
Rhodium(I)-Catalyzed Aryl C-H Carboxylation of 2-Arylanilines with CO2
Gao, Yuzhen,Cai, Zhihua,Li, Shangda,Li, Gang
supporting information, p. 3663 - 3669 (2019/05/17)
An unprecedented Rh(I)-catalyzed, amino-group-assisted C-H carboxylation of 2-arylanilines with CO2 under redox-neutral conditions has been developed. This reaction was promoted by a phosphine ligand with t-BuOK as the base and did not require the use of additional strong organometallic reagent. It enabled an efficient direct conversion of a broad range of 2-(hetero)arylanilines including electron-deficient heteroarenes to various phenanthridinones. Possible intermediates of the reaction were also evaluated in the preliminary mechanistic studies.
Nitrogen-Iodine Exchange of Diaryliodonium Salts: Access to Acridine and Carbazole
Wang, Ming,Fan, Qiaoling,Jiang, Xuefeng
supporting information, p. 216 - 219 (2018/01/17)
A nitrogen-iodine exchange protocol of diaryliodonium salts with sodium azide salt is developed for general construction of significant functional acridines and carbazoles, in which introduction of nitrogen at a late stage was successfully established avoiding heteroatom incompatibility. Inorganic sodium azide served as the sole nitrogen atom source in this transformation. The diversiform functional acridines and carbazoles were comprehensively achieved through annulated diaryliodonium salts, respectively. Notably, Acridine orange (a fluorescent indicator for cell lysosomal dye) and Carprofen (a nonsteroidal anti-inflammatory drug) were efficiently established through this protocol.
