Palladium-Catalyzed Allylic Alkylation Reactions of Nucleophilic Allenones: Asymmetric Allylic Alkylation, Z/E Divergent Allylic Alkylation, and [5 + 2] Annulation

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(13), P. 9940 - 9954

Published: June 19, 2024

Metal-catalyzed allenylic substitution reactions where allenes serve as electrophilic precursors have been recognized a rapid way for novel allene construction. On the contrary, chemistry in which act nucleophiles has far less investigated, especially powerful platform such metal-catalyzed allylic alkylation reactions. We herein describe two unprecedented palladium-catalyzed of an nucleophile. In first reaction, using vinyloxazolidinones allyl precursor, asymmetric allylation trisubstituted allenones worked well to prepare array axially chiral tetrasubstituted allenes. Mechanistic studies and density functional theory (DFT) calculations indicated that weak hydrogen-bonding interaction between acidic C(sp2)–H allenone nitrogen anion π-azaallyl-Pd species is key success stereocontrol. This reaction revealed intriguing reactivity nucleophilic time. second with use allenylethylene carbonates π-oxyallyl-Pd precursors, presented unique under different conditions provide divergent synthetic access (E)- (Z)-allenyl diene products. Interestingly, subsequent sequential intramolecular cyclization/isomerization (Z)-product delivered dihydrooxepine derivatives [5 + 2] annulation

Language: Английский

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Palladium-Catalyzed Ligand-Directed Divergent Decarboxylative Cycloadditions of Vinyloxazolidine-2,4-diones with 1,3,5-Triazinanes

Organic Letters, Journal Year: 2024, Volume and Issue: 26(8), P. 1589 - 1594

Published: Feb. 22, 2024

This study demonstrates a highly efficient regiodivergent ligand-controlled palladium-catalyzed cycloaddition reaction of vinyloxazolidine-2,4-diones with 1,3,5-triazinanes. In the presence diphosphine ligand, proceeds via (5+2) pathway to afford 1,3-diazepin-4-ones in excellent yields, while using monophosphine smoothly (3+2) give imidazolidin-4-ones good yields.

Language: Английский

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4-Vinylbenzodioxinones as a new type of precursor for palladium-catalyzed (4+3) cycloaddition of azomethine imines

Chemical Communications, Journal Year: 2024, Volume and Issue: 60(11), P. 1436 - 1439

Published: Jan. 1, 2024

Benzo-fused cyclic carbonates were designed and synthesized as a novel type of precursor π-allylpalladium zwitterionic intermediates.

Language: Английский

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Palladium-Catalyzed Asymmetric Decarboxylation of 5-Vinyloxazolidine-2,4-Diones Triggering the Dearomatization of Electron-Deficient Indoles for the Synthesis of Chiral Highly Functionalized Pyrroloindolines

Organic Letters, Journal Year: 2024, Volume and Issue: 26(15), P. 3310 - 3315

Published: April 8, 2024

A catalyst system consisting of a chiral phosphoramidite ligand and Pd2(dba)3·CHCl3 causes the decarboxylation 5-vinyloxazolidine-2,4-diones to generate amide-containing aza-π-allylpalladium 1,3-dipole intermediates, which are capable triggering dearomatization 3-nitroindoles for diastereo- enantioselective [3+2] cycloaddition, leading formation series highly functionalized pyrroloindolines containing three contiguous stereogenic centers with excellent results (up 99% yield, 88:12 dr, 96% ee).

Language: Английский

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Enantioselective Synthesis of Oxazocines via MQ‐Phos Enabled Palladium‐Catalyzed Asymmetric Formal [4+4]‐Cycloadditions

Advanced Science, Journal Year: 2024, Volume and Issue: 11(31)

Published: June 17, 2024

Abstract Oxazocines are key structural intermediates in the synthesis of natural products and pharmaceutical molecules. However, oxazocines especially a highly enantioselective manner, is long‐standing formidable challenge due to unfavorable energetics involved cyclization. Herein, series new PNP‐Ligand P ‐chiral stereocenter first designed synthesized, called MQ‐Phos , successfully applied it Pd‐catalyzed higher‐order formal [4+4]‐cycloaddition α β ‐unsaturated imines with 2‐(hydroxymethyl)‐1‐arylallyl carbonates. The reaction features mild conditions, excellent regio‐ enantiocontrol broad substrate scope (54 examples). Various medium‐sized rings can be afforded moderate yields (up 92%) enantioselectivity 99% ee). newly developed critical for ring catalytic reactivity enantioselectivity.

Language: Английский

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Palladium-Catalyzed [5 + 4] Cycloaddition of 4-Vinyl-4-Butyrolactones with N-Tosyl Azadienes: Construction of Nine-Membered Ring

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(7), P. 5019 - 5028

Published: March 19, 2024

In this paper, we reported the palladium-catalyzed formal [5 + 4] cycloaddition reactions between 4-vinyl-4-butyrolactones (VBLs) and azadienes. Under mild reaction conditions, a wide range of benzofuran-fused 9-membered heterocyclic compounds had been provided in moderate to excellent yields with exclusive regioselectivities diastereoselectivities. The practical applicability synthesis was demonstrated through scale-up further transformation.

Language: Английский

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Palladium-Catalyzed Asymmetric (3 + 2) Cycloaddition of 5-Allenyloxazolidine-2,4-Diones with Barbiturate-Derived Alkenes: Synthesis of Spirobarbiturate-γ-Lactams

Organic Letters, Journal Year: 2023, Volume and Issue: 25(34), P. 6328 - 6333

Published: Aug. 23, 2023

The 5-allenyloxazolidine-2,4-diones had been synthesized as novel precursors of π-allyl palladium zwitterion and were applied in a palladium-catalyzed enantioselective (3 + 2) annulation by using barbiturate-derived alkenes the reaction partner presence an axially chiral phosphoramidite ligand. This proceeded smoothly under mild conditions, affording highly functionalized spirobarbiturate-γ-lactam derivatives excellent yields along with high diastereo- enantioselectivities. scale-up further transformation product also successful.

Language: Английский

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Palladium-Catalyzed Decarboxylative Allylic Sulfonylation of Vinyloxazolidine-2,4-diones: Synthesis of γ-Sulfonyl-α,β-unsaturated Amides

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

Published: Feb. 10, 2025

A palladium-catalyzed decarboxylative allylic sulfonylation reaction of vinyloxazolidine-2,4-diones with inexpensive and readily available sodium sulfinates as reagents has been developed. Under the catalysis Pd(PPh3)4, a wide range γ-sulfonyl-α,β-unsaturated amides can be synthesized in good to excellent yields. The developed protocol is characterized by exclusive regioselectivity, mild conditions, broad substrate scope, functional group tolerance, suitable for gram-scale synthesis.

Language: Английский

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Palladium‐Catalyzed Enantioselective [4+2] Cycloaddition of 4‐Vinylbenzodioxinones with Barbiturate‐Derived Alkenes: Con‐struction of Chiral Spirobarbiturate−Chromanes

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(24)

Published: Feb. 21, 2024

In this paper, Pd-catalyzed [4+2] decarboxylative cycloaddition of 4-vinylbenzodioxinones with barbiturate-derived alkenes has been developed, leading to various spirobarbiturate-chromane derivatives in high yields excellent diastereo- and enantioselectivities. The scale-up reaction further derivation the product were demonstrated. A plausible mechanism was also proposed.

Language: Английский

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Diastereo- and Enantioselective (3 + 2) Cycloaddition of a New Aza-π-Allylpalladium Zwitterionic Intermediate

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(14), P. 9941 - 9945

Published: July 10, 2023

Cycloaddition of azaoxyallyl cations or other C─(C═O)─N synthon precursors is a well-established route toward lactams and N-heterocycles, but despite the wide synthetic scope this approach, enantioselective versions remain scarce. We herein report 5-vinyloxazolidine-2,4-diones (VOxD) as suitable precursor new palladium-π-allylpalladium intermediate. In presence electrophilic alkenes, (3 + 2) γ-lactam cycloadducts could be formed with high level diastereo- enantioselectivity.

Language: Английский

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