Lewis Acid-Enabled Chemodivergent Cycloadditions of Donor–Acceptor Cyclopropanes with Indoline-2-Thiones

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

Published: Feb. 20, 2025

Lewis acid-enabled reactions of donor-acceptor cyclopropanes (DACs) with indoline-2-thiones are reported. The reaction exhibits tunable annulation depending on the acid and substituent at N1 indoline-2-thiones. With AlCl3 as 1-isopropylindoline-2-thiones reactants, a direct ring opening DACs, followed by intramolecular nucleophilic addition/dehydration takes place leading to formation dihydro-2H-thiepino[2,3-b]indoles in moderate good yields. Using Yb(OTf)3 promoter 1-unsubstituted (3 + 2) cycloaddition DACs accompanied sulfur rearrangement give 3-indolyl-4,5-dihydrothiophenes In addition, synthetic transformation 3-indolyl-4,5-dihydrothiophene sulfone indole-based axially chiral scaffolds further extends utility structural complexity.

Language: Английский

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Synthesis of Bridged Bicyclic Systems peri‐Annulated to the Indole Ring: Tropane‐Fused Indoles

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(12), P. 2784 - 2790

Published: April 23, 2024

Abstract Ytterbium triflate catalysed domino reaction of (3‐formyl‐4‐indolyl)‐derived donor‐acceptor cyclopropane with primary amines provides a simple approach to an unprecedented tetracyclic skeleton in which tropane system is peri ‐annulated indole core. This process involves the formation imine and its (3+2)‐cross‐cycloaddition moiety, yielding tropane‐fused core under mild conditions. These products are significant interest for pharmacology as potential hybrid molecules dual mode action.

Language: Английский

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Domino-Annulation-Based Approach to Synthesize Bridged Bis-thiopyrano[2,3-b]indoles and Unbridged Thiopyrano[2,3-b]indoles

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: April 9, 2025

A novel domino strategy for the construction of intricate bridged bis-thiopyrano[2,3-b]indoles was disclosed, which involved one molecule 3-formylchromones and two molecules indoline-2-thiones, enabling formation four new bonds in a single operation. The transformation occurred under mild reaction conditions, facilitated by synergistic action base NaHCO3 catalytic acid ZnCl2. Notably, when these bis-thiopyrano[2,3-b]indole skeletons were treated with alkyl halides basic they underwent deconstruction to yield alkylthio-substituted indole-decorated thiopyrano[2,3-b]indoles.

Language: Английский

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Strain-Releasing Hydrogenation of Donor–Acceptor Cyclopropanes and Cyclobutanes via Electrochemical Site Selective Carbonyl Reduction

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

Published: April 21, 2025

An acid or hydrogen gas-free electrochemical protocol is established for the hydrogenation of strained rings (cyclopropane and cyclobutane) at room temperature atmospheric pressure. The mechanistic study revealed that reaction was initiated via reduction carbonyl group. methodology highly specific toward such as cyclopropane cyclobutane, which exhibit broad functional group tolerance.

Language: Английский

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DFT Study on the Mechanism of Phosphine-Catalyzed Ring-Opening Reaction of Cyclopropyl Ketone

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

In the present study, mechanism, origin of chemoselectivity, and substituent effects phosphine-catalyzed ring-opening reaction cyclopropyl ketone have been investigated using DFT method. Multiple pathways, including formation hydrofluorenone, Cloke-Wilson product, cyclopenta-fused were studied compared. The computational results show that pathway for hydrofluorenone is most favorable one, which involves four processes: nucleophilic substitution to open three-membered ring, an intramolecular Michael addition enolate intermediate, [1,5]-proton transfer give ylide, Wittig deliver final product. For disclosing structural analysis local reactivity index performed. Moreover, also considered QTAIM analysis. current study would provide useful insights understanding chemoselective reactions.

Language: Английский

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In(OTf)3-Catalyzed Formal (4 + 3) Cycloaddition Reactions of 3-Benzylideneindoline-2-thiones with 2-Indolylmethanols

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(29), P. 5902 - 5906

Published: Jan. 1, 2024

We report the In(OTf)

Language: Английский

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