Palladium-Catalyzed Ligand-Controlled Switchable Hetero-(5 + 3)/Enantioselective [2σ+2σ] Cycloadditions of Bicyclobutanes with Vinyl Oxiranes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(29), P. 19621 - 19628

Published: May 13, 2024

For nearly 60 years, significant research efforts have been focused on developing strategies for the cycloaddition of bicyclobutanes (BCBs). However, higher-order and catalytic asymmetric BCBs long-standing formidable challenges. Here, we report Pd-catalyzed ligand-controlled, tunable cycloadditions divergent synthesis bridged bicyclic frameworks. The dppb ligand facilitates formal (5+3) vinyl oxiranes, yielding valuable eight-membered ethers with scaffolds in 100% regioselectivity. Cy-DPEphos promotes selective hetero-[2σ+2σ] to access pharmacologically important 2-oxabicyclo[3.1.1]heptane (O-BCHeps). Furthermore, corresponding O-BCHeps 94–99% ee has achieved using chiral (S)-DTBM-Segphos, representing first cross-dimerization two strained rings. obtained are promising bioisosteres ortho-substituted benzenes.

Language: Английский

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Divergent Synthesis of Sulfur‐Containing Bridged Cyclobutanes by Lewis Acid Catalyzed Formal Cycloadditions of Pyridinium 1,4‐Zwitterionic Thiolates and Bicyclobutanes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: May 31, 2024

Bridged cyclobutanes and sulfur heterocycles are currently under intense investigation as building blocks for pharmaceutical drug design. Two formal cycloaddition modes involving bicyclobutanes (BCBs) pyridinium 1,4-zwitterionic thiolate derivatives were described to rapidly expand the chemical space of sulfur-containing bridged cyclobutanes. By using Ni(ClO

Language: Английский

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Visible-Light-Induced [4 + 3]-Annulation of Carbonyl Ylides with Alkenyl Pyrazolinone for Constructing [4.2.1]-Oxo-Bridged Oxocine Skeleton

Organic Letters, Journal Year: 2025, Volume and Issue: 27(2), P. 709 - 714

Published: Jan. 7, 2025

Herein, we present a visible-light-induced protocol for the synthesis of highly functionalized oxo-bridged oxocine skeletons. This method generates carbenes via ortho-acyl diazo compounds, which are rapidly intercepted by oxygen atom an intermolecular acyl group to form cyclic 1,3-dipole. The in situ generated reactive 1,3-dipole undergoes facile formal [4 + 3] cycloaddition with alkenyl pyrazolinone, yielding [4.2.1]-oxo-bridged compounds.

Language: Английский

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Advances in Catalytic Asymmetric Reactions Involving o-Hydroxybenzyl Alcohols

Chinese Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 43(3), P. 974 - 974

Published: Jan. 1, 2023

a 江苏师范大学化学与材料科学学院 江苏徐州 221116

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Fungicide-inspired precursors of π-allylpalladium intermediates for palladium-catalyzed decarboxylative cycloadditions

Chemical Science, Journal Year: 2023, Volume and Issue: 14(11), P. 3024 - 3029

Published: Jan. 1, 2023

Inspired by a fungicide, we designed 5-vinyloxazolidine-2,4-diones as new precursors of π-allylpalladium zwitterionic intermediates and developed palladium-catalyzed asymmetric (5 + 3) cycloaddition with azomethine imines (3 2) 1,1-dicyanoalkenes. Both reactions proceeded smoothly under mild reaction conditions to produce various chiral heterocyclic compounds in high yields excellent enantioselectivities. These results revealed that were type suitable precursor for palladium catalysis will find extensive applications Pd-catalyzed such allylic alkylation.

Language: Английский

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Recent advances of Pd-π-allyl zwitterions in cycloaddition reactions

Chinese Chemical Letters, Journal Year: 2023, Volume and Issue: 34(11), P. 108401 - 108401

Published: March 30, 2023

Language: Английский

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Synthesis of S(IV)‐Stereogenic Chiral Thio‐Oxazolidinones via Palladium‐Catalyzed Asymmetric [3+2] Annulations

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(13)

Published: Jan. 29, 2024

Organic molecules bearing chiral sulfur stereocenters exert a great impact on asymmetric catalysis and synthesis, drugs, materials. Compared with acyclic ones, the catalytic synthesis of thio-heterocycles has largely lagged behind due to lack efficient synthetic strategies. Here we establish first modular platform access thio-oxazolidinones via Pd-catalyzed [3+2] annulations vinylethylene carbonates sulfinylanilines. This protocol is featured by readily available starting materials, high enantio- diastereoselectivity. In particular, an unusual effect non-chiral supporting ligand diastereoselectivity was observed. Possible reaction mechanisms stereocontrol models were proposed.

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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Synthesis of Chiral Endocyclic Allenes and Alkynes via Pd-Catalyzed Asymmetric Higher-Order Dipolar Cycloaddition

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 18, 2024

A Pd-catalyzed asymmetric higher-order dipolar cycloaddition between allenyl carbonates and azadienes is achieved by exploiting novel alkylidene-π-allyl-Pd dipoles. This research provides a modular platform for the synthesis of challenging chiral endocyclic allenes bearing medium-sized heterocyclic motif centrally stereocenter in good yields with high enantio- diastereoselectivities (29 examples, up to 97% yield, 97:3 er >19:1 dr). Experimental computational studies elucidate possible reaction mechanism observed stereochemical results. Based on mechanistic understanding, new π-propargyl-Pd dipole was designed further extend success higher order strategy 10-membered alkynes from propargyl (13 98% yield 94.5:5.5 er).

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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