65826-95-1

Usage

Chemical Properties

Pale yellow liquid

InChI:InChI=1/C9H11N/c1-7-2-3-9-8(6-7)4-5-10-9/h2-3,6,10H,4-5H2,1H3

Upstream product

• 614-96-0 5-methyl-1H-indole 
• 1309978-90-2 5-methylindoline-1-carbaldehyde 
• 52163-09-4 acetaldehyde p-tolylhydrazone 
• 539-44-6 N-4-methylphenylhydrazine 
• 500227-35-0 5-methyl-1-trifluoromethanesulfonyl-2,3-dihydro-1H-indole 

Downstream Products

• 96014-87-8 2-(2,3-dihydro-5-methyl-1H-indol-1-yl)benzonitrile 
• 179024-62-5 1-(5-methyl-2,3-dihydro-1H-indol-7-yl)-1-phenylmethanone 
• 1331944-21-8 C₂₄H₂₅FN₂O 
• 1620581-33-0 2-isobutyl-2-(2-methoxy-5-((5-methylindolin-1-yl)sulfonyl)phenyl)-4-methylpentanenitrile 
• 1233701-24-0 5-methyl-1-[(2-nitrophenyl)sulfonyl]indoline 
• 925916-15-0 4-(5-methyl-3-indolyl)-2-butanone 

Relevant academic research and scientific papers

Pd/C-Catalyzed transfer hydrogenation ofN-H indoles with trifluoroethanol and tetrahydroxydiboron as the hydrogen source

Under the guidance of the known mechanism of the hydrogenation of indoles and transfer hydrogenation with tetrahydroxydiboron (B2(OH)4), Pd/C catalyzed transfer hydrogenation ofN-H indoles with trifluoroethanol and tetrahydroxydiborane as the hydrogen source has been developed. This provides an efficient strategy and catalytic system for the reduction of un-activatedN-H indoles, andN-H indolines are obtained with good to excellent yields. In addition, a series of the isotopic labelling experiments were carried out to probe the mechanism.

Palladium-Catalyzed Direct and Specific C-7 Acylation of Indolines with 1,2-Diketones

The indole scaffold is a ubiquitous and useful substructure, and extensive investigations have been conducted to construct the indole framework and/or realize indole modification. Nevertheless, the direct selective functionalization on the benzenoid core must overcome the high activity of the C-3 position and still remains highly challenging. Herein, a palladium-catalyzed direct and specific C-7 acylation of indolines in the presence of an easily removed directing group was developed. This strategy usually is considered as a practical strategy for the preparation of acylated indoles because indoline can be easily converted to indole under oxidation conditions. In particular, our strategy greatly improved the alkacylation yield of indolines for which only an unsatisfactory yield could be achieved in the previous studies. Furthermore, the reaction can be scaled up to gram level in the standard reaction conditions with a much lower palladium loading (1 mol %).

Covalent Organic Frameworks toward Diverse Photocatalytic Aerobic Oxidations

Photoactive two-dimensional covalent organic frameworks (2D-COFs) have become promising heterogenous photocatalysts in visible-light-driven organic transformations. Herein, a visible-light-driven selective aerobic oxidation of various small organic molecules by using 2D-COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone-based 2D-COF-1 on molecular oxygen activation, a wide range of amides, quinolones, heterocyclic compounds, and sulfoxides were obtained with high efficiency and excellent functional group tolerance under very mild reaction conditions. Furthermore, benefiting from the inherent advantage of heterogenous photocatalysis, prominent sustainability and easy photocatalyst recyclability, a drug molecule (modafinil) and an oxidized mustard gas simulant (2-chloroethyl ethyl sulfoxide) were selectively and easily obtained in scale-up reactions. Mechanistic investigations were conducted using radical quenching experiments and in situ ESR spectroscopy, all corroborating the proposed role of 2D-COF-1 in photocatalytic cycle.

Synthesis and Photophysical Study of Heteropolycyclic and Carbazole Motif: Nickel-Catalyzed Chelate-Assisted Cascade C-H Activations/Annulations

Herein, nickel-catalyzed synthesis of polyarylcarbazole through sequential C-H bond activations has been described. Regioselective indole C2/C3 functionalization has been achieved in the presence of indole C7-H, which is quite challenging. In addition, this approach also gives easy access to building a heteropolycyclic motif through C6/C7 C-H functionalization of indoline. This methodology is not limited to aromatic internal alkynes as coupling partners; aliphatic alkynes have also shown good tolerance. Notably, during the optimization the catalytic enhancement with sodium iodide as an additive has been observed. We have also studied the photophysical properties of these highly conjugated molecules.

Indoline Catalyzed Acylhydrazone/Oxime Condensation under Neutral Aqueous Conditions

Acylhydrazones formation has been widely applied in materials science and biolabeling. However, their sluggish condensation rate under neutral conditions limits its application. Herein, indolines with electron-donating groups are reported as a new catalyst scaffold, which can catalyze acylhydrazone, hydrazone, and oxime formation via an iminium ion intermediate. This new type of catalyst showed up to 15-fold rate enhancement over the traditional anilinecatalyzed reaction at neutral conditions. The identified indoline catalyst was successfully applied in hydrogel formation.

Aerobic Dehydrogenation of N-Heterocycles with Grubbs Catalyst: Its Application to Assisted-Tandem Catalysis to Construct N-Containing Fused Heteroarenes

An aerobic dehydrogenation of nitrogen-containing heterocycles catalyzed by Grubbs catalyst is developed. The reaction is applicable to various nitrogen-containing heterocycles. The exceptionally high functional group compatibility of this method was confirmed by the oxidation of an unprotected dihydroindolactam V to indolactam V. Furthermore, by taking advantage of the oxygen-mediated structural change of the Grubbs catalyst, we integrated ring-closing metathesis and subsequent aerobic dehydrogenation to develop the novel assisted-tandem catalysis using molecular oxygen as a chemical trigger. The utility of the assisted-tandem catalysis was demonstrated by the concise synthesis of N-containing fused heteroarenes including a natural antibiotic, pyocyanine.

Re-Catalyzed Annulations of Weakly Coordinating N-Carbamoyl Indoles/Indolines with Alkynes via C?H/C?N Bond Cleavage

Described herein are rhenium-catalyzed [3+2] annulations of N-carbamoyl indoles with alkynes via C?H/C?N bond cleavage, which provide rapid access to fused-ring pyrroloindolone derivatives. For the first time, the weakly coordinating O-directing group was successfully employed in rhenium-catalyzed C?H activation reactions, enabled by the unique catalytic trio of Re2(CO)10, Me2Zn and ZnCl2. Mechanistic studies revealed that aminozinc species plays an important role in the reaction. Based on the mechanistic understanding, a more powerful catalytic trio of Re2(CO)10, [MeZnNPh2]2 and Zn(OTf)2 was devised and applied successfully in the [4+2] annulations of indolines and alkynes affording pyrroloquinolinone derivatives.

Hydrophobic Metal Halide Perovskites for Visible-Light Photoredox C?C Bond Cleavage and Dehydrogenation Catalysis

Two-dimensional lead and tin halide perovskites were prepared by intercalating the long alkyl group 1-hexadecylammonium (HDA) between the inorganic layers. We observed visible-light absorption, narrow-band photoluminescence, and nanosecond photoexcited lifetimes in these perovskites. Owing to their hydrophobicity and stability even in humid air, we applied these perovskites in the decarboxylation and dehydrogenation of indoline-2-carboxylic acids. (HDA)2PbI4 or (HDA)2SnI4 were investigated as photoredox catalysts for these reactions, and quantitative conversion and high yields were observed with the former.

Sustainable Radical Cascades to Synthesize Difluoroalkylated Pyrrolo[1,2-a]indoles

We disclose herein a photocatalytic difluoroalkylation and cyclization cascade reaction of N-(but-2-enoyl)indoles with broad substrate scopes in up to 90% isolated yield. This method provides sustainable and efficient access to synthesize difluoroalkylated pyrrolo[1,2-a]indoles with a quaternary carbon center under mild conditions.

Expedient cobalt(II)-catalyzed site-selective C7-arylation of indolines with arylboronic acids

Cobalt(ii)-catalyzed pyrimidyl directing group-assisted C7 arylation of indolines with arylboronic acids has been developed using Mn(OAc)2·4H2O as an oxidant. The use of cobalt(ii)-PCy3 as a catalyst and broad substrate scope are the important practical features.