Dirhodium(II)/Xantphos-Catalyzed Relay Carbene Insertion and Allylic Alkylation Process: Reaction Development and Mechanistic Insights

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(30), P. 11799 - 11810

Published: July 23, 2021

Although dirhodium-catalyzed multicomponent reactions of diazo compounds, nucleophiles and electrophiles have achieved great advance in organic synthesis, the introduction allylic moiety as third component via metal intermediate remains a formidable challenge this area. Herein, an attractive three-component reaction readily accessible amines, compounds enabled by novel dirhodium(II)/Xantphos catalysis is disclosed, affording various architecturally complex functionally diverse α-quaternary α-amino acid derivatives good yields with high atom step economy. Mechanistic studies indicate that transformation through relay dirhodium(II)-catalyzed carbene insertion alkylation process, which catalytic properties dirhodium are effectively modified coordination Xantphos, leading to activity process.

Language: Английский

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Recent advances in metal-catalysed asymmetric sigmatropic rearrangements

Chemical Science, Journal Year: 2022, Volume and Issue: 13(42), P. 12290 - 12308

Published: Jan. 1, 2022

Catalytic asymmetric sigmatropic rearrangements induced by chiral metal catalysis have been intensively explored. This review summarizes recent significant advances, mainly involving [3,3], [2,3] and [1,3]-rearrangements.

Language: Английский

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Rhodium-catalyzed cascade reactions of triazoles with organoselenium compounds – a combined experimental and mechanistic study

Chemical Science, Journal Year: 2021, Volume and Issue: 12(18), P. 6362 - 6369

Published: Jan. 1, 2021

Herein, we report on our studies the reaction of organoselenium compounds with triazoles under thermal conditions using simple Rh(ii) catalysts.

Language: Английский

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Catalyst-Controlled Regiodivergence in Rearrangements of Indole-Based Onium Ylides

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(24), P. 9016 - 9025

Published: June 14, 2021

We have developed catalyst-controlled regiodivergent rearrangements of onium-ylides derived from indole substrates. Oxonium ylides formed in situ substituted indoles selectively undergo [2,3]- and [1,2]-rearrangements the presence a rhodium copper catalyst, respectively. The combined experimental density functional theory (DFT) computational studies indicate divergent mechanistic pathways involving metal-free ylide catalyzed reaction favoring [2,3]-rearrangement, metal-coordinated ion-pair [1,2]-rearrangement that recombines solvent-cage. application our methodology was demonstrated first total synthesis alkaloid (±)-sorazolon B, which enabled stereochemical reassignment natural product. Further group transformations rearrangement products to generate valuable synthetic intermediates were also demonstrated.

Language: Английский

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Overview of Transition Metal Catalyzed Multicomponent Reactions Based on Trapping of Allylic Electrophiles

ChemCatChem, Journal Year: 2024, Volume and Issue: 16(4)

Published: Jan. 11, 2024

Abstract Multicomponent reactions provide an excellent approach toward quaternary carbon centres utilizing convergent chemical in a highly selective manner under one‐pot conditions. The reactivity of substrates and metal catalysts is carefully controlled, precluding the formation side‐products. In this context, transition catalyzed onium ylides generated via diazo precursors nucleophiles with third component (an electrophile) have garnered significant attention. Using allylic precursor as electrophilic partner provides opportunities to construct all‐carbon centres. Furthermore, presence allyl fragment multicomponent product serves pivotal handle for carrying out subsequent modifications. Several recent studies employed Rh, Pd, dual Rh/Pd catalytic systems involving alkylation that proceed synergistic or relay pathway. Although not significantly successful, few cases, asymmetric induction achieved through chiral phosphoric acids phosphine ligands. Limited substrate catalyst scope underlying mechanistic complexities posed formidable challenges, slowing advancement reactions. This review details using readily available like compounds, carbonates, (R‐OH, R‐NH 2 , etc .) forming complex organic compounds. Our primary objective discuss issues may facilitate progress field.

Language: Английский

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Asymmetric Cyclopropanation of Primary N-Vinylamides via Carbene Transfer Catalyzed by Cationic Rh(I)/Diene Complexes: An Unexpected Outer-Sphere Mechanism

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(12), P. 9385 - 9396

Published: June 6, 2024

A highly enantioselective intermolecular [2 + 1] cycloaddition of primary N-vinylamides with carbene intermediates was developed by taking advantage cationic rhodium(I)/diene catalysis under mild conditions at room temperature. This cyclopropanation method facilitates rapid access to enantioenriched cyclopropylamides, an important motif in drug discovery, generally good yields and high stereoselectivities (>20:1 dr, up 99% ee). approach employs a rhodium(I) catalyst form pre-equilibrium complex enamide substrate. Kinetic experiments comprehensive density functional theory (DFT) calculations were performed elucidate the reaction mechanism. The kinetic data DFT results support existence resting-state between two substrates. computational studies show that involves interesting, unexpected outer-sphere mechanistic pathway involving sole Rh(I) catalytic cycle major product reveal diazo decomposition step is rate-determining step.

Language: Английский

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Effects of Axial Solvent Coordination to Dirhodium Complexes on the Reactivity and Selectivity in C–H Insertion Reactions: A Computational Study

Organometallics, Journal Year: 2021, Volume and Issue: 40(24), P. 4120 - 4132

Published: Dec. 3, 2021

Density functional theory calculations were used to systematically explore the effects of axial ligation by solvent molecules on reactivity and selectivity dirhodium tetracarboxylates with diazo compounds in context C–H insertion into propane. Insertions three types compounds─acceptor/acceptor, donor/acceptor, donor/donor─promoted tetraformate tested without for no surrounding solvent, dichloromethane, isopropanol, acetonitrile. Magnitudes, origins, consequences structural electronic changes arising from characterized. The results suggest that affects barriers N2 extrusion insertion, former a larger extent.

Language: Английский

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Hexafluoroisopropanol for the Selective Deactivation of Poisonous Nucleophiles Enabling Catalytic Asymmetric Cyclopropanation of Complex Molecules

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(20), P. 12530 - 12542

Published: Sept. 30, 2022

In the presence of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), nucleophilic and reactive reagents are prevented from interacting with a rhodium carbene, allowing asymmetric cyclopropanation to occur high yield stereoselectivity on variety compounds. A high-throughput screen was conducted complementary catalytic system in 90 different poisonous nucleophiles varying amounts HFIP (10 equiv, used as reaction solvent). The scope both aryl/heteroaryl diazoacetate olefin expanded, study culminated enantioselective functionalization complex molecules including API natural products.

Language: Английский

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Mechanism and stereoselectivity in metal and enzyme catalyzed carbene insertion into X–H and C(sp²)–H bonds

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(22), P. 11004 - 11044

Published: Jan. 1, 2024

This review provides a mechanistic overview of asymmetric Fe, Cu, Pd, Rh, Au and heme-based enzymes catalyzed carbene insertion reactions to construct C–X (X = O, N, S, etc. ) C–C bonds, focusing on the stereochemical models.

Language: Английский

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Dimethoxyacetaldehyde-N-triftosylhydrazone: Preparation and Carbene Reactivity in Cyclopropanation and Doyle–Kirmse Reactions

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

Published: Feb. 20, 2025

Herein, we developed the new, powerful, and easy-to-handle chemical reagent, dimethoxyacetaldehyde-N-triftosylhydrazone (DMHz-Tfs), as a convenient in situ source of dimethoxydiazoethane under mild conditions. We demonstrate carbene reactivity DMHz-Tfs iron-catalyzed cyclopropanation Doyle-Kirmse reactions, providing access to diverse acetal functionalized cyclopropanes homoallylic- allenyl-sulfides at gram-scale with high stereoselectivity. DFT calculations elucidated involvement most stable doublet spin state iron-carbene intermediate over other possible states.

Language: Английский

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