64420-99-1Relevant 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.
TfOH-Promoted Transition-Metal-Free Cascade Trifluoroethylation/Cyclization of Organic Isothiocyanates by Phenyl(2,2,2-trifluoroethyl)iodonium Triflate
Zhao, Cheng-Long,Han, Qiu-Yan,Zhang, Cheng-Pan
supporting information, p. 6480 - 6484 (2018/10/09)
An efficient and transition-metal-free method for the synthesis of the structurally diversified trifluoroethylthiol phenanthridines and 3,4-dihydroisoquinolines is described. Various 2-isothiocyanobiaryls and aryl alkyl isothiocyanates reacted with phenyl(2,2,2-trifluoroethyl)iodonium triflate in CH2Cl2 in the presence of trifluoromethanesulfonic acid at 40 °C to form the corresponding trifluoroethylation/cyclization products in good to quantitative yields. This work represents the first construction of trifluoroethylthiol phenanthridine and isoquinoline derivatives from isothiocyanates in the absence of transition-metal catalysts by a one-pot procedure.
Palladium-Catalyzed C-H Bond Activation by Using Iminoquinone as a Directing Group and an Internal Oxidant or a Co-oxidant: Production of Dihydrophenanthridines, Phenanthridines, and Carbazoles
Raju, Selvam,Annamalai, Pratheepkumar,Chen, Pei-Ling,Liu, Yi-Hung,Chuang, Shih-Ching
supporting information, p. 4134 - 4137 (2017/08/15)
A palladium-catalyzed C-H bond activation reaction, via a redox-neutral pathway, for the preparation of dihydrophenanthridine, phenanthridine, and carbazole derivatives from biaryl 2-iminoquinones is developed. The preinstalled iminoquinone was designed to act as a directing group for ortho C-H activation and an internal oxidant or a co-oxidant. This catalysis proceeded through the following sequence: C-H bond activation, coordination and insertion of activated olefins, β-hydride elimination, H-shift, insertion, and protonation or β-hydride elimination. In addition, carbazoles can be prepared efficiently by using this method without the addition of external oxidants.
Palladium on Carbon-Catalyzed C?H Amination for Synthesis of Carbazoles and its Mechanistic Study
Monguchi, Yasunari,Okami, Hiroki,Ichikawa, Tomohiro,Nozaki, Kei,Maejima, Toshihide,Oumi, Yasunori,Sawama, Yoshinari,Sajiki, Hironao
supporting information, p. 3145 - 3151 (2016/10/09)
10% Palladium on carbon (10% Pd/C) successfully catalyzed the intramolecular C?H amination of various N-mesylated 2-aminobiphenyls in the presence of a catalytic amount of pyridine N-oxide in heated dimethyl sulfoxide (DMSO) under an oxygen atmosphere to afford the corresponding N-mesylcarbazoles. The reaction would proceed via a single-electron transfer process based on its significant suppression by the addition of a single-electron scavenger, tetracyanoquinodimethane (TCNQ), and the substituents on the aromatic rings of the substrate have an insignificant effect on the reaction progress. (Figure presented.).
Synthesis of Fluorenes Starting from 2-Iodobiphenyls and CH2Br2 through Palladium-Catalyzed Dual C-C Bond Formation
Shi, Guangfa,Chen, Dushen,Jiang, Hang,Zhang, Yu,Zhang, Yanghui
supporting information, p. 2958 - 2961 (2016/07/06)
A facile and efficient approach is developed for the synthesis of fluorene and its derivatives starting from 2-iodobiphenyls and CH2Br2. A range of fluorene derivatives can be synthesized under relatively mild conditions. The reaction proceeds via a tandem palladium-catalyzed dual C-C bond formation sequence through the key dibenzopalladacyclopentadiene intermediates, which are obtained from 2-iodobiphenyls through palladium-catalyzed C-H activation.
Cascade C-H Functionalization/Amidation Reaction for Synthesis of Azepinone Derivatives
Bai, Peng,Huang, Xing-Fen,Xu, Guo-Dong,Huang, Zhi-Zhen
supporting information, p. 3058 - 3061 (2016/07/13)
A cascade C-H functionalization/amidation reaction of aminobiaryls with diazomalonates has been developed under rhodium catalysis, affording new azepinone derivatives in moderate to excellent yields.
Palladium-Catalyzed Selective Aryl Ring C–H Activation of N-Acyl-2-aminobiaryls: Efficient Access to Multiaryl-Substituted Naphthalenes
Annamalai, Pratheepkumar,Chen, Wu-Yin,Raju, Selvam,Hsu, Kou-Chi,Upadhyay, Nitinkumar Satyadev,Cheng, Chien-Hong,Chuang, Shih-Ching
supporting information, p. 3642 - 3648 (2016/11/25)
Palladium-catalyzed cycloaromatization of N-acyl-2-aminobiaryls, through a sequence of ortho C?H bond activation/alkyne insertion/meta C?H bond activation/alkyne insertion, was developed. An efficient synthesis of multiaryl-substituted naphthalenes, N-[2-(5,6,7,8-tetraarylnaphthalen-1-yl)aryl]acetamides, was demonstrated using molecular oxygen as the sole oxidant. Furthermore, through Buchwald's synthetic protocol, two compounds were converted into corresponding fluorescent carbazoles in 30–40% yield by intramolecular C?N bond formation. (Figure presented.).
Direct synthesis of N -H carbazoles via iridium(III)-catalyzed intramolecular C-H amination
Suzuki, Chiharu,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
supporting information, p. 1597 - 1600 (2015/03/30)
The iridium-catalyzed dehydrogenative cyclization of 2-aminobiphenyls proceeds smoothly in the presence of a copper cocatalyst under air as a terminal oxidant through intramolecular direct C-H amination to produce N-H carbazoles. A similar iridium/copper system can also catalyze the unprecedented dimerization reaction of 2-aminobiphenyl involving 2-fold C-H/N-H couplings.
Transition-metal-free synthesis of phenanthridinones from biaryl-2-oxamic acid under radical conditions
Yuan, Ming,Chen, Li,Wang, Junwei,Chen, Shenjie,Wang, Kongchao,Xue, Yongbo,Yao, Guangmin,Luo, Zengwei,Zhang, Yonghui
, p. 346 - 349 (2015/02/19)
Na2S2O8-promoted decarboxylative cyclization of biaryl-2-oxamic acid for phenanthridinones has been developed. This work illustrates the first example of intramolecular decarboxylative amidation of unactivated arene under transition-metal-free conditions. Additionally, this approach provides an efficient and economical method to access biologically interesting phenanthridinones, an important structure motif in many natural products. (Chemical Equation Presented).
Free-amine-directed alkenylation of C(sp2)-H and cycloamination by palladium catalysis
Liang, Zunjun,Ju, Long,Xie, Yongju,Huang, Lehao,Zhang, Yuhong
supporting information, p. 15816 - 15821 (2013/01/16)
A new protocol for the palladium-catalyzed free-amine-directed alkenylation of C(sp2)-H bonds and cycloamination is described. Substituted biaryl-2-amines react with various alkenes, including electron-deficient alkenes, aryl alkenes and alkyl alkenes, to give the corresponding phenanthridines with exclusive regioselectivity. The use of α-branched styrenes leads to the formation of tricyclic compounds with a seven-membered amine ring. The method operates through a free-amine-directed alkenylation and a subsequent hydroamination cyclization reaction. Seven-membered cycloamination: A new protocol for the palladium-catalyzed free-amine-directed alkenylation of C(sp2)-H bonds and subsequent cycloamination is described (see scheme). Substituted biaryl-2-amines react with various alkenes to give the corresponding phenanthridines with exclusive regioselectivity. The use of α-branched styrenes leads to the formation of tricyclic compounds with a seven-membered amine ring. Copyright
