117788-15-5Relevant articles and documents
Traceless directing strategy: Efficient synthesis of N-alkyl indoles via redox-neutral C-H activation
Wang, Chengming,Huang, Yong
, p. 5294 - 5297 (2013)
A general protocol for the synthesis of N-alkyl indoles has been developed via a redox neutral C-H activation strategy using a traceless nitroso directing group. A broad scope of substituted N-alkyl indoles has been prepared in good to excellent yields using a very simple Rh catalyst system in the absence of an external oxidant or any other additive. Good to excellent regioselectivity has been achieved for asymmetrically disubstituted acetylenes.
One-Pot Tandem ortho-Naphthoquinone-Catalyzed Aerobic Nitrosation of N-Alkylanilines and Rh(III)-Catalyzed C-H Functionalization Sequence to Indole and Aniline Derivatives
Si, Tengda,Kim, Hun Young,Oh, Kyungsoo
, p. 1152 - 1163 (2021/01/14)
The nitroso group served as a traceless directing group for the C-H functionalization of N-alkylanilines, ultimately removed after functioning either as an internal oxidant or under subsequent reducing conditions. The unique ability of o-NQ catalysts to aerobically oxidize the N-alkylanilines without using solvents and stoichiometric amounts of oxidants has rendered the new opportunity to develop the telescoped catalyst systems without a need for directly handling the hazardous N-nitroso compounds.
Assembly of Indole Cores through a Palladium-Catalyzed Metathesis of Ar-X σ-Bonds
Ferrier, Robert C.,Ghasemi, Mehran,Habibi, Azizollah,Jafarpour, Farnaz,Navid, Hamed,Rajai-Daryasarei, Saideh,Safaie, Niloofar
supporting information, p. 9556 - 9561 (2020/12/21)
We describe the development of a new method for construction of highly substituted indole scaffolds through the strategic utilizing of the metathesis of Ar-X σ-bonds based on the dynamic nature of palladium-based oxidative addition/reductive elimination. A suitable and simple catalytic system has provided an appropriate platform for a productive ligand exchange and consecutive carbopalladation/C-H activation/amination of phosphine ligands with alkynes and aromatic/aliphatic amines for construction of structurally diverse indoles.
A Fast Track to Indoles and Annulated Indoles through ortho- vs ipso-Amination of Aryl Halides
Jafarpour, Farnaz,Ghasemi, Mehran,Mohaghegh, Farid,Asgari, Sara,Habibi, Azizollah
supporting information, p. 10143 - 10148 (2019/12/24)
A complementary site selective ortho- vs ipso-amination of aryl halides using non-electrophilic amine sources for construction of indole scaffolds is reported. A palladium-catalyzed alkyne insertion/C-H activation/palladacycle amination via merger of three easily diversified components including iodoarenes, alkynes, and amines delivers indoles with different substitution patterns even in gram scales. By employing ortho-bromoanilines, a consecutive annulative π-extension of indoles proceeds to construct indolo[1,2-f]phenanthridine scaffolds via four C-C and C-N bond formations in one pot.
Predicting the Outcome of Photocyclisation Reactions: A Joint Experimental and Computational Investigation
Wonanke, A. D. Dinga,Ferguson, Jayne L.,Fitchett, Christopher M.,Crittenden, Deborah L.
, p. 1293 - 1303 (2019/02/25)
Photochemical oxidative cyclodehydrogenation reactions are a versatile class of aromatic ring-forming reactions. They are tolerant to functional group substitution and heteroatom inclusion, so can be used to form a diverse range of extended polyaromatic systems by fusing existing ring substituents. However, despite their undoubted synthetic utility, there are no existing models—computational or heuristic—that predict the outcome of photocyclisation reactions across all possible classes of reactants. This can be traced back to the fact that “negative” results are rarely published in the synthetic literature and the lack of a general conceptual framework for understanding how photoexcitation affects reactivity. In this work, we address both of these issues. We present experimental data for a series of aromatically substituted pyrroles and indoles, and show that quantifying induced atomic forces upon photoexcitation provides a powerful predictive model for determining whether a given reactant will photoplanarise and hence proceed to photocyclised product under appropriate reaction conditions. The propensity of a molecule to photoplanarise is related to localised changes in charge distribution around the putative forming ring upon photoexcitation. This is promoted by asymmetry in molecular structures and/or charge distributions, inclusion of heteroatoms and ethylene bridging and well-separated or isolated photocyclisation sites.
Rhodium(iii)-catalyzed indole synthesis at room temperature using the transient oxidizing directing group strategy
Shang, Yaping,Jonnada, Krishna,Yedage, Subhash Laxman,Tu, Hua,Zhang, Xiaofeng,Lou, Xin,Huang, Shijun,Su, Weiping
supporting information, p. 9547 - 9550 (2019/08/15)
Rh-catalyzed reactions of N-alkyl anilines with internal alkynes at room temperature have been developed using an in situ generated N-nitroso group as a transient oxidizing directing group. Due to mild reaction conditions, this method enabled synthesis of a broad range of N-alkyl indoles, including even two indole-based medicinal compounds. Our work disclosed the feasibility of the transient oxidizing directing group strategy in C-H functionalization reactions, which possesses the potential to enhance overall step-economy and impart new reactivity patterns to substrates.
Br?nsted acid cocatalysis in photocatalytic intramolecular coupling of tertiary amines: Efficient synthesis of 2-arylindols
Yuan, Xiaoqian,Wu, Xinxin,Dong, Shupeng,Wu, Guibing,Ye, Jinxing
supporting information, p. 7447 - 7450 (2016/08/16)
We report herein a highly efficient intramolecular coupling reaction of tertiary amines and ketones (α,β-unsaturated ketones) by using a Br?nsted acid as a cocatalyst, affording 2-arylindols in good to excellent yields (up to 92%) under visible light irra
Co(III)-Catalyzed, Internal and Terminal Alkyne-Compatible Synthesis of Indoles
Zhou, Shuguang,Wang, Jinhu,Wang, Lili,Chen, Kehao,Song, Chao,Zhu, Jin
supporting information, p. 3806 - 3809 (2016/08/16)
A Co(III)-catalyzed, internal and terminal alkyne-compatible indole synthesis protocol is reported herein. The N-amino (hydrazine) group imparts distinct, diverse reactivity patterns for directed C-H functionalization/cyclization reactions. Notable synthetic features include regioselectivity for a meta-substituted arylhydrazine, regioselectivity for a chain-branched terminal alkyne, formal incorporation of an acetylenic unit through C2-desilylation on a C2-silylated indole derivative, formal inversion of regioselectivity through consecutive C3-derivatization and C2-desilylation processes, and formal bond migration for a linear-chain terminal alkyne.
Rhodium-catalyzed annulation of tertiary aniline N-oxides to N-alkylindoles: Regioselective C-H activation, oxygen-atom transfer, and N-dealkylative cyclization
Li, Bin,Xu, Hong,Wang, Huanan,Wang, Baiquan
, p. 3856 - 3862 (2016/07/06)
[Cp?RhIII]-catalyzed annulation of tertiary aniline N-oxides with alkynes was reported to achieve the challenging ortho C-H functionalization of tertiary anilines via N-O bond acting as a traceless directing group. More significantly, this system represents the first example which integrates C-H activation, oxygen-atom transfer, and N-dealkylative cyclization in one reaction. This unprecedented coupling reaction has allowed the construction of N-alkylindole derivatives in high efficiency with broad substrate scope and good functional group tolerance.
Cationic Cobalt(III) Catalyzed Indole Synthesis: The Regioselective Intermolecular Cyclization of N-Nitrosoanilines and Alkynes
Liang, Yujie,Jiao, Ning
supporting information, p. 4035 - 4039 (2016/03/19)
The unique regioselectivity and reactivity of cobalt(III) in the direct cyclization of N-nitrosoanilines with alkynes for the expedient synthesis of N-substituted indoles is demonstrated. In the presence of a cobalt(III) catalyst, high regioselectivity was observed when using unsymmetrical meta-substituted N-nitrosoanilines. Moreover, internal alkynes bearing electron-deficient groups, which are almost unreactive in the [Cp?RhIII]-catalyzed system, display good reactivity in this transformation.
