Pd-Catalyzed Ligand-Directed Divergent Cycloaddition of Cyclic 1-Azadienes with Oxo-1,4-dipoles

Organic Letters, Journal Year: 2023, Volume and Issue: 25(27), P. 5011 - 5016

Published: June 29, 2023

Ligand-directed divergent synthesis (LDS) is an important synthetic tool for the preparation of structurally diverse organic molecules without tedious steps to modify substrates. Herein, we introduce realization 3,4-, 1,2-, and 1,4-cyclization benzo[d]isothiazole-1,1-dioxide-fused azadienes (BDAs) through LDS, leading tetrahydro-2H-pyrans, oxazinanes, tetrahydro-2H-1,5-oxazocines, respectively. Using phosphinooxazoline (PHOX) ligands, have developed a [4 + 2] cycloaddition between BDAs substituted 2-alkylidenetrimethylene carbonates, providing access multi-substituted chiral tetrahydro-2H-pyrans in good yields with excellent enantio-, diastereo-, regioselectivities.

Language: Английский

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Copper-Catalyzed Enantioselective Formal [4 + 1] and [3 + 3] Cycloaddition of Ethynylethylene Carbonates

Organic Letters, Journal Year: 2023, Volume and Issue: 25(51), P. 9213 - 9218

Published: Dec. 15, 2023

Herein we employed ethynylethylene carbonates (EECs) to achieve formal [4 + 1] and [3 3] cycloaddition with cyclic 1,3-dicarbonyl compounds. On one hand, EECs styryl substitution could undergo a remotely controlled enantioselective reaction. This reaction exhibits good chemoselectivity, regioselectivity, enantioselectivity. In addition, of compounds was also achieved, leading series 4H-pyrans impressive chemoselectivity

Language: Английский

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Tandem Allylic Amination/oxa-Michael Addition of Vinyl Methylene Cyclic Carbonates via Palladium-Organo Relay Catalysis

Organic Letters, Journal Year: 2023, Volume and Issue: 25(30), P. 5624 - 5629

Published: July 24, 2023

A tandem allylic amination/oxa-Michael addition of vinyl methylene cyclic carbonates (VMCCs) has been developed to construct heterocycles by single palladium catalysis or palladium-organo relay catalysis. In this process, the bisnucleophiles first underwent regioselective amination, and then second nucleophilic group further completed hetero-Michael reaction form a series heterocycles. Among them, chiral 3,4-dihydro-2H-benzo[b][1,4]oxazines could be produced in medium high yield with good enantioselectivity under

Language: Английский

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Palladium‐Catalyzed [4+2] and [6+2] Dipolar Cycloadditions for the Construction of Benzo[d]isothiazole 1,1‐Dioxide Fused 1,3‐Oxazinanes and 1,3‐Oxazocanes^†

Chinese Journal of Chemistry, Journal Year: 2023, Volume and Issue: 42(8), P. 829 - 834

Published: Dec. 8, 2023

Comprehensive Summary The Pd‐catalyzed dipolar cycloaddition represents a significant synthetic strategy for the construction of useful heterocyclic compounds. This study developed [4+2] and [6+2] reactions benzo[ d ]isothiazole 1,1‐dioxides (BDs) leading to synthesis BD‐fused 1,3‐oxazinane 1,3‐oxazocane derivatives, respectively. In particular, 1,3‐oxazinanes demonstrated regio‐ enantioselective characteristics, resulting in products with good yields, enantioselectivity regioselectivity (if applicable). Furthermore, reaction this work represented first medium‐sized ring compounds based on BDs.

Language: Английский

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Synthesis of medium-sized heterocycles from oxetanes based on an allylic amination/ring-opening strategy

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(97), P. 14467 - 14470

Published: Jan. 1, 2023

The construction of medium-sized ring compounds has been a prominent research area in synthetic chemistry. In this study, we developed tandem strategy that combines allylic amination and ring-opening oxetanes to synthesize heterocycles. Specifically, N-aryl oxetan-3-amines undergo with zwitterionic π-allylpalladium, followed by intramolecular ring-opening, resulting the formation Notably, are able achieve synthesis 7-8 membered heterocycles moderate good yields employing different types π-allylpalladium species.

Language: Английский

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Asymmetric 2,4-Dienylation/[4 + 2] Annulation Cascade to Construct Fused Frameworks via Auto-Tandem Palladium Catalysis

Organic Letters, Journal Year: 2023, Volume and Issue: 25(20), P. 3682 - 3686

Published: May 16, 2023

A palladium catalyzed tandem reaction between ortho-functionalized aryl enones and 2,4-dienyl carbonates has been presented, proceeding through sequential 2,4-dienylation/Michael addition/π-σ-π isomerization/allylic alkylation. broad array of enantioenriched architectures having fused spirocyclic frameworks are constructed in moderate to excellent yields stereoselectivity. Notably, the intrinsic intramolecular Diels-Alder pattern dienylated intermediates is well reversed via Pd(0)-π-Lewis base catalysis.

Language: Английский

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Rapid Access to Divergent Fused Polycycles Via One‐Pot A³ Coupling and Intramolecular Diels‐Alder Reaction

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(41)

Published: May 16, 2024

Abstract Divergent nitrogen‐containing fused polycyclic ring systems are constructed from simple starting materials via a one‐pot aldehyde‐alkyne‐amine (A 3 ) coupling and intramolecular Diels‐Alder reaction. This domino reaction directly furnishes linear 5/5/5 5/5/6, or nonlinear 5/5/6/5, rings containing an oxa‐bridged 5/5 bicycle 1,6‐enyne substructure. One‐step derivation of the leads to polyfunctionalized with tetrahydrofuran back‐to‐back pyrroline 6/5 hexahydro‐1 H ‐isoindole structure, while cycloisomerizing enyne substructure adds extra 5‐membered afford functionalized 5/5/5/5 5/5/5/5/5 selected substrates. In addition, product can be designed so that alkyne moiety is hydroalkoxylated form additional heterocyle in 5/5/5/6 5/5/6/5/5 system. diversity‐oriented synthetic approach thus allows rapid access under‐explored structural space for discovery new biological non‐biological activities functions.

Language: Английский

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Studies on the [4 + 2] cycloaddition and allylic substitution of indole-fused zwitterionic π-allylpalladium

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 21(40), P. 8162 - 8169

Published: Jan. 1, 2023

The zwitterionic π-allylpalladium species, also known as dipoles, are important synthons widely used in various reactions including cycloaddition and allylic substitution. This study reported the development of a new indole-fused precursor compound its application [4 + 2] substitution reactions. As result, synthesis pyrrolo[3,2,1-ij]quinazolin-3-one 7-vinyl indole compounds was achieved with moderate to good yields. Notably, reaction exhibited excellent regio- stereoselectivity.

Language: Английский

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Copper‐Catalyzed Formal [4+2] Cycloaddition of Ethynylethylene Carbonates for the Construction of 3,4‐Dihydro‐2H‐benzo[b][1,4]oxazines

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 27(25)

Published: April 9, 2024

Abstract A formal [4+2] cycloaddition reaction of ethynylethylene carbonates and 2‐aminophenols has been developed for the synthesis 3,4‐dihydro‐2 H ‐benzo[ b ][1,4]oxazines bearing quaternary carbon atoms. The features mild conditions, good functional group compatibility yields. Furthermore, when using chiral PyBox ligand, this strategy could also achieve asymmetric ][1,4]oxazines. Application studies indicated that hydroxymethyl final products was an excellent can be further modified easily.

Language: Английский

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Synthesis of Benzopyrone-Fused Hydrobenzo[c,d]indoles via Cascade Annulation of p-Quinamines and 3-Formylchromones

Organic Letters, Journal Year: 2024, Volume and Issue: 26(33), P. 7031 - 7036

Published: Aug. 12, 2024

A 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed cascade annulation reaction between

Language: Английский

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