Chiral dinitrogen ligand enabled asymmetric Pd/norbornene cooperative catalysis toward the assembly of C–N axially chiral scaffolds

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: June 8, 2024

Abstract C − N axially chiral compounds have recently attracted significant interest among synthetic chemistry community due to their widespread application in pharmaceuticals, advanced materials and organic synthesis. Although the emerging asymmetric Catellani reaction offers great opportunity for modular efficient preparation, only operative NBE strategy date requires using half stoichiometric amount of 2,6-disubstituted bromoarenes as electrophiles. We herein report an assembly C–N scaffolds through a distinct ligand strategy. The crucial source, biimidazoline (BiIM) dinitrogen ligand, is used relatively low loading permits use less bulky bromoarenes. method also features feedstock plain NBE, high reactivity, good enantioselectivity, ease operation scale-up. Applications preparation optoelectronic material candidates featuring two axes C–H activation been demonstrated.

Language: Английский

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Intermolecular Buchwald–Hartwig Reactions for Enantioselective Synthesis of Diverse Atropisomers: Rerouting the C–N Forming Mechanism to Substrate Oxygen-Assisted Reductive Elimination

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(24), P. 16567 - 16580

Published: June 7, 2024

Axially chiral biaryls featuring a C–N axis are important functional molecules in diverse fields. The asymmetric Buchwald–Hartwig reaction represents powerful strategy for these targets. Previous studies, however, have been predominantly restricted to intramolecular atroposelective coupling, likely due the steric and entropic effects reductive elimination of Pd(II) species with sterically congested aryl nitrogen groups. We now report two intermolecular coupling systems bulky NH lactams halohydrocarbons enabled by rerouting mechanism one that accommodates challenging substrates. Both exhibited group tolerance, excellent enantioselectivity, high Z selectivity (if applicable), affording atropisomeric biaryl olefins through de novo construction axis. Experimental computational studies were performed elucidate mechanism, switch pathways is traced effect (ortho substituent) halide substrate. A 2,6-disubstituted reorients proximal lactamide ligand its unusual O-ligation mode. With amide oxygen participation, this intermediate undergoes an accessible barrier five-membered ring transition state, pathway as well induction mode has much underexplored catalysis.

Language: Английский

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Palladium-Catalyzed Modular Synthesis of Thiophene-Fused Polycyclic Aromatics via Sequential C–H Activation

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

Published: Jan. 29, 2025

A palladium-catalyzed Catellani-type [2+2+2] annulation reaction of aryl iodides, bromothiophenes, and norbornadiene, which proceeds via a tandem Heck coupling/double C-H bond activation retro-Diels-Alder pathway to access thiophene-fused polyaromatics, is reported. The key feature this protocol represents NBD/NBE retaining annulation.

Language: Английский

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Rhodium(III)-Catalyzed Redox-Neutral [4 + 2] Annulation of 3,5-Diaryloxadiazoles with Alkynes: A Dual C–H Activation Strategy for Constructing C–N Atropisomers

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

Published: April 22, 2025

A rhodium(III)-catalyzed dual-ring formation via cascade C-H activation/[4 + 2] annulation of 3,5-diaryoxadiazoles with alkynes was developed. This strategy has been demonstrated a variety 3,5-diaryloxadiazoles and alkynes, it successfully scaled up to gram-scale synthesis, highlighting its potential significance in the direct construction C-N atropisomers. Furthermore, cleavage N-O bond is essential for bicyclic structure absence an external oxidant. Mechanistic studies revealed that at 3-phenyl group oxadiazole likely rate-determining step this reaction.

Language: Английский

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Enantioconvergent Synthesis of Chiral Fluorenols from Racemic Secondary Alcohols via Pd(II)/Chiral Norbornene Cooperative Catalysis

Chemical Science, Journal Year: 2024, Volume and Issue: 15(21), P. 7975 - 7981

Published: Jan. 1, 2024

An efficient protocol for the asymmetric synthesis of fluorenols has been developed through an enantioconvergent process enabled by Pd(ii)/chiral norbornene cooperative catalysis. This approach allows facile access to diverse functionalized chiral with constantly excellent enantioselectivities, applying readily available racemic secondary ortho-bromobenzyl alcohols and aryl iodides as starting materials.

Language: Английский

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New trends for transition metal-catalyzed ortho/ipso difunctionalizations of arenes

Chem, Journal Year: 2024, Volume and Issue: 10(9), P. 2651 - 2665

Published: July 29, 2024

Language: Английский

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Synthesis of 1,2-Disubstituted C-Aryl Glycosides via Palladium/Norbornene Cooperative Catalysis

Organic Letters, Journal Year: 2024, Volume and Issue: 26(22), P. 4711 - 4715

Published: May 29, 2024

The Catellani reaction offers an opportunity to address multiple chemical bonds in a single pot. However, it is still quite challenge construct fully substituted olefins via this strategy, especially electron-rich, unstable, and highly functionalized glycals. Herein we report the first palladium-catalyzed for direct preparation of 1,2-disubstituted C-aryl glycosides from easily available 2-iodoglycals, bromoaryl, alkene/alkyne substrates. This transformation exhibits wide substrate scope, accommodating diverse functional groups intricate molecular frameworks. innovative reactivity efficient pathway valuable carbohydrate analogues building blocks, facilitating novel strategic bond disconnections broadening landscape palladium catalysis.

Language: Английский

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