246019-65-8Relevant academic research and scientific papers
Ir(iii)-Catalysed electrooxidative intramolecular dehydrogenative C-H/N-H coupling for the synthesis of N-H indoles
Chang, Sukbok,Kim, Dongwook,Kim, Youyoung
supporting information, p. 12309 - 12312 (2021/12/07)
Herein, an iridium(iii)-catalysed electrooxidative intramolecular dehydrogenative C-H/N-H coupling of unprotected 2-alkenyl anilines is described. The developed method allows the synthesis of a variety of 3-substituted N-H indole scaffolds under undivided electrolytic conditions. Mechanistic studies suggest that the reaction proceeds through the electro-oxidation induced reductive elimination pathway.
Experimental and Computational Studies on Cp*CyRh(III)/KOPiv-Catalyzed Intramolecular Dehydrogenative Cross-Couplings for Building Eight-Membered Sultam/Lactam Frameworks
Li, Liping,Gao, Hui,Sun, Ming,Zhou, Zhi,Yi, Wei
, p. 5473 - 5478 (2020/07/14)
Described herein is an unusual Cp*CyRh(III)-catalyzed intramolecular site-specific aryl C-H annulation, a highly chemoselective protocol providing direct access to eight-membered sultams/lactams with broad substrate/functional group tolerance. Experimental and computational studies reveal that such a transformation involves a unique PivOH-assisted aryl C-H activation/alkene insertion/β-H elimination/hydrogen-transfer process involving the Rh(III)-hydride species as the active intermediate with the concomitant release of H2 as the major byproduct, thus enabling the developed Cp*CyRh(III) catalysis with redox-neutral and highly atom-economical features.
Ynamide Smiles Rearrangement Triggered by Visible-Light-Mediated Regioselective Ketyl-Ynamide Coupling: Rapid Access to Functionalized Indoles and Isoquinolines
Chen, Yang-Bo,Sun, Zhou,Wang, Ze-Shu,Ye, Long-Wu,Zhang, Hao-Wen,Zhu, Chunyin
supporting information, p. 3636 - 3644 (2020/03/06)
In the past decades, significant advances have been made on radical Smiles rearrangement. However, the eventually formed radical intermediates in these reactions are limited to the amidyl radical, except for the few examples initiated by a N-centered radical. Here, a novel and practical radical Smiles rearrangement triggered by photoredox-catalyzed regioselective ketyl-ynamide coupling is reported, which represents the first radical Smiles rearrangement of ynamides. This method enables facile access to a variety of valuable 2-benzhydrylindoles with broad substrate scope in generally good yields under mild reaction conditions. In addition, this chemistry can also be extended to the divergent synthesis of versatile 3-benzhydrylisoquinolines through a similar ketyl-ynamide coupling and radical Smiles rearrangement, followed by dehydrogenative oxidation. Moreover, such an ynamide Smiles rearrangement initiated by intermolecular photoredox catalysis via addition of external radical sources is also achieved. By control experiments, the reaction was shown to proceed via key ketyl radical and α-imino carbon radical intermediates.
Pd-catalyzed regiodivergent synthesis of diverse oxindoles enabled by the versatile heck reaction of carbamoyl chlorides
Wu, Xianqing,Tang, Zaiquan,Zhang, Chengxi,Wang, Chenchen,Wu, Licheng,Qu, Jingping,Chen, Yifeng
supporting information, p. 3915 - 3921 (2020/06/08)
We report herein a miscellaneous oxindole synthesis bearing an all-carbon quaternary center, enabled by Pd-catalyzed intramolecular cyclization followed by multiple intermolecular Heck reactions of both easily accessible alkene-tethered carbamoyl chlorides and olefins. This protocol obviates the use of prefunctionalized olefinic reagents, exhibits excellent functional group tolerance, and features fascinating reactive versatility.
Water-Soluble Hypervalent Iodine(III) Having an I-N Bond. A Reagent for the Synthesis of Indoles
Xia, Hai-Dong,Zhang, Yan-Dong,Wang, Yan-Hui,Zhang, Chi
supporting information, p. 4052 - 4056 (2018/07/15)
A readily accessible and bench-stable water-soluble hypervalent iodine(III) reagent (phenyliodonio)sulfamate (PISA) with an I-N bond was synthesized, and its structure was characterized by X-ray crystallography. With PISA, various indoles were synthesized via C-H amination of 2-alkenylanilines involving an aryl migration/intramolecular cyclization cascade with excellent regioselectivity in aqueous CH3CN. Notably, using this new method as the key step, not only two drug molecules, indometacin and zidometacin, but also another bioactive molecule, pravadoline, were synthesized.
Direct Electrophilic C?H Alkynylation of Unprotected 2-Vinylanilines
Caspers, Lucien D.,Finkbeiner, Peter,Nachtsheim, Boris J.
supporting information, p. 2748 - 2752 (2017/03/08)
Unprotected aromatic amines can be used as directing groups in metal-catalyzed C?H alkynylations of alkenes. By using low amounts of an IrIIIcatalyst in combination with alkynylbenziodoxolones as electrophilic alkyne-transfer reagents, highly desirable 1,3-enynes were isolated in excellent yields of up to 98 % with Z stereoselectivity. A broad substrate scope as well as the high synthetic utility of the 1,3-enynes render this new method an efficient approach for the synthesis of five- and six-membered heterocycles. Further derivatizations of the 1,3-enynes to highly substituted quinolines through AuI- and N-bromosuccinimide-mediated exo-dig cyclizations were demonstrated.
NH2-directed C-H alkenylation of 2-vinylanilines with vinylbenziodoxolones
Boelke, Andreas,Caspers, Lucien D.,Nachtsheim, Boris J.
supporting information, p. 5344 - 5347 (2017/11/07)
The first directing-group-mediated C-H alkenylation with alkenyl-λ3-iodanes as electrophilic alkene-transfer reagents has been developed. The application of free aromatic amines as challenging but synthetically valuable directing groups in combination with an IrIII catalyst enabled the synthesis of highly desirable 1, 3- dienes in excellent yields of up to 98% with high to perfect (Z, E) stereoselectivity. A broad substrate scope and further synthetic modifications are demonstrated.
Br?nsted Acid-Catalyzed Synthesis of N-Arylindoles from 2-Vinylanilines and Quinones
Zhang, Han-Ming,Gao, Zhong-Hua,Yi, Liang,Ye, Song
supporting information, p. 2671 - 2674 (2016/10/11)
In the presence of a quinone, Br?nsted acid-catalyzed intramolecular C?N bond formation of o-vinylanilines by electrophilic cyclization was developed, giving the corresponding N-arylindoles in good to high yields. The reaction worked well for o-vinylanilines with terminal and internal C=C double bonds.
Copper-catalyzed trifluoromethylation of alkenes: Synthesis of trifluoromethylated benzoxazines
Jana, Sadhan,Ashokan, Athira,Kumar, Shailesh,Verma, Ajay,Kumar, Sangit
supporting information, p. 8411 - 8415 (2015/08/06)
A simple base and ligand free copper catalyzed method for the construction of trifluoromethylated benzoxazines has been developed by using Umemoto's reagent. It involves the oxidative difunctionalization of alkenes through tandem C-O and C-CF3 bond formations. Furthermore, synthesized benzoxazines were selectively converted into trifluoromethylated allylic and (E)-vinylic benzamides by the treatment of KOtBu and CH3Li, respectively.
Acyliminium ion-olefin cyclization leading to isoindolo[2,1-a]quinoline derivatives
Pigeon, Pascal,Othman, Mohamed,Netchitailo, Pierre,Decroix, Bernard
, p. 691 - 695 (2007/10/03)
Isoindolo[2,1-a]quinolines 10, 11, 12 were synthesized from hydroxylactams 8 or 9 via an N-acyliminium ion-π-olefin nucleophile cyclization reaction.
