Spiroindoles as Intermediates/Products in Transition Metal-Catalyzed Dearomatization of Indoles

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(14), P. 9442 - 9475

Published: July 3, 2023

Spirocyclic indole derivatives are fascinating tridimensional molecular scaffolds from both a synthetic and biological point of view. Among the many strategies developed to access these structures, transition metal catalysis has recently led impressive advances, especially relying on unique reactivity dearomatized spirocyclic intermediates. These species can indeed evolve toward or nonspirocyclic products through rearomatization-driven processes, which at same time highly challenging control but also source large structural diversity. This review highlights most prominent methods past decade that involve spirocyclization tethered functional group may be activated by metal, leading rearomatized products. The discussion is particularly focused spiroindoleninium intermediate complex mechanistic features regarding its evolution, dependent catalytic systems.

Language: Английский

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Visible-light-induced intramolecular charge transfer in the radical spirocyclisation of indole-tethered ynones

Chemical Science, Journal Year: 2019, Volume and Issue: 11(5), P. 1353 - 1360

Published: Dec. 13, 2019

Indole-tethered ynones form an intramolecular electron donor–acceptor complex that can undergo visible-light-induced charge transfer to promote thiyl radical generation from thiols. This initiates a novel chain sequence, based on dearomatising spirocyclisation with concomitant C–S bond formation. Sulfur-containing spirocycles are formed in high yields using this simple and mild synthetic protocol, which neither transition metal catalysts nor photocatalysts required. The proposed mechanism is supported by various mechanistic studies, the unusual initiation mode represents only second report of use synthesis.

Language: Английский

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Electrochemical Multicomponent Cascade Radical Process Enabling Synthesis of Iodomethyl Spiropyrrolidinyl‐Oxindoles

Chinese Journal of Chemistry, Journal Year: 2024, Volume and Issue: 42(15), P. 1691 - 1698

Published: March 19, 2024

Comprehensive Summary A novel electrochemical multicomponent cascade reaction of indole‐tethered alkenes with CF 3 SO 2 Na and n ‐Bu 4 NI has been developed, which enables the rapid assembly spiropyrrolidinyl‐oxindoles in good yields. The experimental results DFT calculations suggest that this proceeds through oxidation Na, radical coupling alkene, spirocyclization, sulfinate, iodide substitution, water coupling. This strategy features mild conditions, easy‐to‐handle reactants, chemical finding not only enriches research contents but also provides a green for construction compared existing methodologies.

Language: Английский

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Tandem Reactions of Ynones: via Conjugate Addition of Nitrogen‐, Carbon‐, Oxygen‐, Boron‐, Silicon‐, Phosphorus‐, and Sulfur‐Containing Nucleophiles

Advanced Synthesis & Catalysis, Journal Year: 2019, Volume and Issue: 361(21), P. 4839 - 4881

Published: July 4, 2019

Abstract Ynones are widely used in organic synthesis. Their great success is rooted their multiple functional groups. This review focus on advance of ynones published the decade 2009–2019. Reactions triggered by conjugate addition nitrogen‐, carbon‐, oxygen‐, boron‐, silicon‐, phosphorus‐, and sulfur‐containing nucleophiles thoroughly discussed summarized herein. Multicomponent reactions, rearrangements, cycloadditions, regio‐ stereoselective synthesis, oxidations, coupling, green chemistry et al. depicted detail. We hope that this will promote future research area. magnified image

Language: Английский

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Visible‐Light‐Promoted Selenylative Spirocyclization of Indolyl‐ynones toward the Formation of 3‐Selenospiroindolenine Anticancer Agents

Chemistry - An Asian Journal, Journal Year: 2020, Volume and Issue: 15(10), P. 1536 - 1539

Published: March 24, 2020

Abstract A metal‐free and efficient visible‐light‐induced spirocyclization of indolyl‐ynones with diselenides at room temperature under air atmosphere to prepare 3‐selenospiroindolenines in moderate good yields has been developed. The resulting products were tested for vitro anticancer activity by MTT assay, compounds 3 c e showed potent cancer cell‐growth inhibition activities.

Language: Английский

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Indole-ynones as Privileged Substrates for Radical Dearomatizing Spirocyclization Cascades

Organic Letters, Journal Year: 2022, Volume and Issue: 24(2), P. 668 - 674

Published: Jan. 5, 2022

Indole-ynones have been established as general substrates for radical dearomatizing spirocyclization cascade reactions. Five distinct and varied synthetic protocols developed─cyanomethylation, sulfonylation, trifluoromethylation, stannylation borylation─using a variety of generation modes, ranging from photoredox catalysis to traditional AIBN methods. The simple easily prepared indole-ynones can be used rapidly generate diverse, densely functionalized spirocycles the potential become routinely explore reactivity. Experimental computational investigations support proposed mechanism suggest that other new methods are now primed development.

Language: Английский

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Novel Stereo‐Induction Pattern in Pudovik Addition/Phospha‐Brook Rearrangement Towards Chiral Trisubstituted Allenes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(22)

Published: March 23, 2024

Abstract Despite the significance of chiral allene skeletons in catalysis, organic synthesis and medicinal chemistry et al., there is a scarcity reports on axially allenyl phosphorus compounds. Here, we disclosed an efficient straightforward cascade reaction between ethynyl ketones phosphine oxides, resulting broad array trisubstituted allenes incorporating moiety high yields with excellent stereoselectivities facilitated by peptide‐mimic phosphonium salt (PPS) Additionally, comprehensive series mechanistic experiments have been conducted to elucidate that this proceeds via asymmetric Pudovik addition followed subsequent phospha ‐Brook rearrangement occurs concomitantly kinetic resolution, representing stereospecific protonation process facilitating central‐to‐axial chirality transfer manner. We anticipate our research will pave way for promising exploration novel stereo‐induction pattern addition/ reaction.

Language: Английский

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Ynones in dearomative spirocyclisation processes; a review

Tetrahedron Chem, Journal Year: 2024, Volume and Issue: 9, P. 100055 - 100055

Published: Jan. 14, 2024

This review concentrates on our research into the discovery of novel ynone-based dearomative spirocyclisation processes, whilst placing new chemistry context existing knowledge. The genesis programme, development efficient synthetic routes to prepare natural products spirobacillene A (1) and B (2), utilised indole ynones. stimulated a much wider study explore reactivity ynones in processes more generally. Routes generate wide range spirocycles were subsequently developed, with reactions tethered indoles, benzofurans, benzisoxazoles, pyrroles, pyridines, isoquinolines, pyrazines, cyclic ketimines, anisoles all discussed herein, these initiated by catalytic Ag(I), Cu(II), Pd(0), photolysis many other reagents. Asymmetric variants some are also discussed, as is further elaboration spirocyclic give carbazoles, quinolones, polycycles useful building blocks. Finally, applications methodology product synthesis (e.g. A, lasubine II indolizidine 209D) described.

Language: Английский

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Indole Synthesis Using Silver Catalysis

Chemistry - An Asian Journal, Journal Year: 2019, Volume and Issue: 14(11), P. 1900 - 1911

Published: March 25, 2019

Abstract Indoles are amongst the most important classes of heteroaromatics in organic chemistry, commonly found biologically active natural products and therapeutically useful compounds. The synthesis indoles is therefore several methods for their that make use silver(I) catalysts reagents have been developed recent years. This Minireview contains, to best our knowledge, a comprehensive coverage silver‐mediated indole forming reactions since first reaction this type was reported 2004.

Language: Английский

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Copper-Catalyzed Trifluoromethylation of Ynones Coupled with Dearomatizing Spirocyclization of Indoles: Access to CF₃-Containing Spiro[cyclopentane-1,3′-indole]

Organic Letters, Journal Year: 2020, Volume and Issue: 22(8), P. 3291 - 3296

Published: March 31, 2020

A one-pot protocol for the Cu(I)-catalyzed difunctionalization of indolyl ynones has been achieved via trifluoromethylation alkyne followed by dearomatizing spirocyclization indoles. This cascade process enables constructing diverse CF3-containing spiro[cyclopentane-1,3′-indole] scaffolds in moderate to excellent yields which have challenging quaternary spirocyclic carbon and tetrasubstituted alkenes.

Language: Английский

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