Designing Cobalt(II) Complex for Chemoselective Synthesis of 2‐Aryl‐3‐Formyl Indoles from Amino Alcohols and Alcohols^†

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(47)

Published: June 20, 2024

An air-stable, inexpensive, and isolable cobalt(II) complex (C1) of N-((1-methyl-1H-imidazol-2-yl)methyl)-2-(phenylselanyl)ethan amine (L1) was synthesized characterized. The used to catalyze a one-pot cascade reaction between 2-(2-aminophenyl)ethanols benzyl alcohol derivatives. Interestingly, 2-aryl-3-formylindole derivatives were formed instead N-alkylated or C-3 alkylated indoles. A broad substrate scope can be activated using this protocol with only 5.0 mol % catalyst loading achieve up 87 yield mechanistic studies suggested that the proceeds through tandem imine formation followed by cyclization.

Language: Английский

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Recent advances in rhodium-catalyzed C(sp²)–H (hetero)arylation

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 19(39), P. 8442 - 8465

Published: Jan. 1, 2021

Recent achievements in rhodium-catalyzed arylations through C(sp 2 )–H bond activation were summarized.

Language: Английский

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Transient Directing Group Strategy as a Unified Method for Site Selective Direct C4–H Halogenation of Indoles

Organic Letters, Journal Year: 2021, Volume and Issue: 23(21), P. 8402 - 8406

Published: Oct. 19, 2021

A unified method for direct C4–H halogenation of indoles has been accomplished with the assistance anthranilic acids as suitable transient directing groups. Exclusive site selectivity (one out five potential reactive sites) well good functional group tolerance was obtained to install three kinds halogen atoms (Cl, Br and I, respectively) by using inexpensive N-halosuccinimides (NXS) sources under mild conditions. Taking advantage rich groups in product, a diversity nitrogen-containing heterocycles were facily constructed via one-step late-stage derivations.

Language: Английский

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Cobalt(II)-Catalyzed Selective C2–H Heck Reaction of Native (N–H) Indoles Enabled by Salicylaldehyde Ligand

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 8, 2025

Direct functionalization of native (N–H) indoles via C–H activation remains a challenge. Herein, we report salicylaldehyde-promoted cobalt-catalyzed selective C2–H Heck reaction with both active and unactivated olefins in the presence free N–H bonds. A series structurally diverse C2-alkenylated including natural product drug derivatives were prepared directly effectively without additional preprotection deprotection procedures.

Language: Английский

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Visible-light-induced aerobic C-3 thiocyanation of indoles using porphyrin as photoredox catalyst

Synthetic Communications, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 12

Published: March 19, 2025

In this work, we report a metal-free and environmentally friendly approach for the electrophilic C–H thiocyanation of indoles under visible light irradiation. Using porphyrin as photocatalyst atmospheric air an oxidant, developed mild efficient route to synthesize series thiocyanate products with both electron-rich electron-deficient systems in moderate good yields. The use radical scavenger like TEMPO helped establish photoredox mechanism. This method offers sustainable promising synthesizing heterocyclic substrates, aromatics, bioactive molecules through catalysis.

Language: Английский

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Synthesis of 2-(2-Nitroalkyl)indoles by Rhodium(III)-Catalyzed C–H Alkylation

Organic Letters, Journal Year: 2023, Volume and Issue: 25(9), P. 1375 - 1379

Published: Feb. 28, 2023

The Rh(III)-catalyzed addition of the indole C2–H bond to nitroalkenes under an ambient atmosphere is disclosed, providing direct access a wide range 2-(2-nitroalkyl)indoles (33 examples) with excellent chemo- and regioselectivity. In addition, pyrrole derivatives also successfully participated in this Friedel–Crafts alkylation reaction. Representative nitroalkane products could be converted into structurally diverse valuable derivatives. Furthermore, series control experiments were conducted, plausible mechanism was proposed.

Language: Английский

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Ir-Catalyzed Enantioselective Formal C–H Conjugate Addition of Pyrrole and Indoles to α,β-Unsaturated Carbonyl Compounds

Organic Letters, Journal Year: 2021, Volume and Issue: 23(23), P. 9078 - 9082

Published: Nov. 15, 2021

The chiral Ir(I)-catalyzed intermolecular reaction of N-carbamoylpyrrole and indole derivatives with α,β-unsaturated carbonyl compounds such as crotonates proceeded high enantioselectivity. obtained chirally functionalized pyrroles indoles are formal C-H conjugate adducts. mechanism was studied by deuterium labeling experiments.

Language: Английский

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Rhodium-Catalyzed C2-Alkylation of Indoles with Cyclopropanols Using N,N-Dialkylcarbamoyl as a Traceless Directing Group

Organic Letters, Journal Year: 2022, Volume and Issue: 24(37), P. 6745 - 6749

Published: Sept. 11, 2022

An efficient rhodium-catalyzed synthesis of C2-alkylated NH-free indoles has been achieved from substituted and cyclopropanols. The reaction allows the various products in good to excellent yield. Important features method include use a N,N-dialkylcarbamoyl group as traceless directing group, C-H/C-C bond functionalization, functional tolerance, broad scope, pyrrolo[1,2-a]indole, identification potential intermediates.

Language: Английский

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Nickel-Catalyzed Direct Synthesis of N-Substituted Indoles from Amino Alcohols and Alcohols

Organic Letters, Journal Year: 2022, Volume and Issue: 24(49), P. 9054 - 9059

Published: Dec. 5, 2022

A one-pot cascade approach for the synthesis of N-substituted indoles from amino alcohols and under additive base-free conditions with liberation water as only stoichiometric byproduct is reported. The commercially available bench-stable Ni(OTf)2 salt in combination 1,2-bis(dicyclohexylphosphino)ethane (dcype) very effective this unprecedented catalytic transformation. broad range substrates including aromatic aliphatic primary alcohols, cyclic acyclic secondary various substituted 2-aminophenyl ethyl are employed reaction to provide a diverse N-alkylated indoles. Mechanistic studies revealed that proceeds through tandem N-alkylation via hydrogen autotransfer followed by cyclization alcohol intermediate.

Language: Английский

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Pd(II)-Catalyzed [5 + 2] Cyclization of N-Triflyl Aryl Indoles and α,γ-Substituted Allenoates: A Route to Indole-Fused Benzodiazepines

Organic Letters, Journal Year: 2023, Volume and Issue: 25(34), P. 6246 - 6250

Published: Aug. 17, 2023

A Pd(II)-catalyzed [5 + 2] annulation between N-triflyl aryl indoles and α,γ-substituted allenoates for the synthesis of indole-fused benzodiazepines is reported. This protocol highly efficient when N-acetylated valine amino acid DMSO have been used as ligand cosolvent, respectively. The substrate scope can be further extended to disubstituted allenoates. reaction mechanism has proposed based on mechanistic studies. Mechanistically, accelerates C-H activation C(sp2)-H bond. Consequent cyclopalladation leads formation a six-membered palladacycle. Subsequent coordination migratory insertion an allenoate forms possible eight-membered intermediate. Reductive elimination followed by [1,3]-H shift results in benzodiazepines.

Language: Английский

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