54147-94-3Relevant academic research and scientific papers
Electrochemical Palladium-Catalyzed Intramolecular C—H Amination of 2-Amidobiaryls for Synthesis of Carbazoles
Gao, Xinlong,Lei, Aiwen,Wang, Pan,Wang, Qingqing,Zhang, Heng,Zhang, Xiaojing
supporting information, p. 143 - 148 (2020/12/18)
The synthesis of carbazoles based on the electrochemical Pd-catalyzed intramolecular C—H amination of 2-amidobiaryls through oxidative cross coupling has been achieved under mild reaction conditions. The reaction can be carried out in undivided cell without the addition of external chemical oxidant. Besides good functional group compatibility, the desired carbazoles can be scaled up and modified easily. Compared with previous methods, this protocol affords a simple and sustainable avenue for the construction of carbazoles.
Palladium-Catalyzed [4 + 3] or [2 + 2 + 3] Annulation via C-H Activation and Subsequent Decarboxylation: Access to Heptagon-Embedded Polycyclic Aromatic Hydrocarbons
Yang, Xiumei,Chen, Xiahong,Xu, Yankun,Zhang, Minghao,Deng, Guobo,Yang, Yuan,Liang, Yun
supporting information, p. 2610 - 2615 (2021/04/12)
The construction of a seven-membered ring in the polycyclic aromatic hydrocarbon skeleton remains a notoriously difficult but attractive challenge. Herein a novel palladium-catalyzed [4 + 3] decarboxylative annulation of 2-iodobiphenyls with 2-(2-halophenyl)acrylic acids is reported, which provides an efficient approach for assembling various tribenzo[7]annulenes via a C-H activation and decarboxylation process. Moreover, tribenzo[7]annulenes can be also synthesized via a [2 + 2 + 3] decarboxylative annulation strategy by employing readily available 1,2-halobenzenes, phenylboronic acids, and 2-(2-halophenyl)acrylic acids.
α-Bromoacrylic Acids as C1 Insertion Units for Palladium-Catalyzed Decarboxylative Synthesis of Diverse Dibenzofulvenes
Zhang, Minghao,Deng, Wenbo,Sun, Mingjie,Zhou, Liwei,Deng, Guobo,Liang, Yun,Yang, Yuan
supporting information, p. 5744 - 5749 (2021/08/18)
Herein α-bromoacrylic acids have been employed as C1 insertion units to achieve the palladium-catalyzed [4 + 1] annulation of 2-iodobiphenyls, which provides an efficient platform for the construction of diverse dibenzofulvenes. This protocol enables the formation of double C(aryl)-C(vinyl) bonds via a C(vinyl)-Br bond cleavage and decarboxylation. It is particularly noteworthy that the method features a broad substrate scope, and various interesting frameworks, such as bridged ring, fused (hetero)aromatic ring, and divinylbenzene, can be successfully incorporated into the products.
Atmosphere-Controlled Palladium-Catalyzed Divergent Decarboxylative Cyclization of 2-Iodobiphenyls and α-Oxocarboxylic Acids
Zhou, Liwei,Sun, Mingjie,Zhou, Fengru,Deng, Guobo,Yang, Yuan,Liang, Yun
supporting information, p. 7150 - 7155 (2021/09/18)
A novel palladium-catalyzed divergent decarboxylative cyclization of 2-iodobiphenyls and α-oxocarboxylic acids utilizing the atmosphere as a controlled switch is reported. Under the protection of a nitrogen atmosphere, tribenzotropones are synthesized by a [4 + 3] decarboxylative cyclization. Employing a palladium/O2 system enables a [4 + 2] decarboxylative cyclization to assemble triphenylenes. Notably, preliminary mechanistic studies indicate that the formation of triphenylenes involves a double decarboxylation.
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.
Synthesis of Fluorescent 4-Azapyrenes by Palladium(II)-Catalyzed Dual C?H Bond Activation and Annulation
Hsiao, Huan-Chang,Annamalai, Pratheepkumar,Jayakumar, Jayachandran,Sun, Shang-You,Chuang, Shih-Ching
supporting information, p. 1695 - 1701 (2021/02/12)
Unique dual-emissive and deep-blue/green fluorescent multi-substituted 4-azapyrenes with bathochromic shift emission, quantum yields up to 0.60 and long excited-state lifetime were synthesized successfully by annulative π-extension reactions. This synthesis constitutes a palladium-catalyzed dehydrogenative annulation of N-acyl-2-aminobiaryls with in situ 1,3-diynes as a key step, giving substituted phenanthrenes via a rollover C?H bond activation, followed by Bischler-Napieralski cyclization. Further π-extension by superacid-mediated cyclization produced a blue fluorescent naphtho 4-azapyrene. (Figure presented.).
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.
Cascade One-Pot Synthesis of Orange-Red-Fluorescent Polycyclic Cinnolino[2,3-f]phenanthridin-9-ium Salts by Palladium(II)-Catalyzed C?H Bond Activation of 2-Azobiaryl Compounds and Alkenes
Jayakumar, Jayachandran,Vedarethinam, Guganchandar,Hsiao, Huan-Chang,Sun, Shang-You,Chuang, Shih-Ching
supporting information, p. 689 - 694 (2019/11/22)
Quaternary ammonium salts were synthesized in moderate to good yields through double oxidative C?H bond activation on azobenzenes. The mechanism of the highly regioselective reaction of 2-azobiaryls with alkenes to give orange-red-fluorescent cinnolino[2,
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.
