Cocatalyst-Dependent Divergent Amination of Alkylgold Intermediates with Azodicarboxylates

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 5211 - 5218

Published: March 12, 2025

The asymmetric electrophilic amination using azodicarboxylates as the N-source for construction of C–N bond has attracted much attention over past decades. However, use in situ formed nucleophilic intermediates, rather than bench-stable reagents, remains elusive and challenging. Herein, we disclose an enantioselective reaction generated alkylgold species with under a gold complex chiral quinine-derived squaramide (QN-SQA) synergetic catalysis, leading to alkylideneoxazolines nitrogen-containing tertiary carbon stereocenter good high yields enantioselectivities. Moreover, starting from same oxazoles incorporating aminomethyl group on 5-position could be obtained by Brønsted acid relay catalysis via alkylideneoxazoline species. This method offers complementary approach through interception With this strategic protocol, further synthetic applications can envisioned catalytic C–C C–X bonds.

Language: Английский

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Synthesis of Masked 2-Pyridones from 1,3-Enynyl Esters via Tandem Gold-Catalyzed Cycloisomerization and Oxidative Nitrogen Insertion

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

Published: March 18, 2025

An efficient synthetic method to regioselectively assemble masked 2-pyridones that relies on sequential gold-catalyzed cycloisomerization and phenyliodonium diacetate (PIDA)-mediated oxidative nitrogen insertion from 1,3-enynyl esters in a one-pot, two-step manner is described. The utility of the cascade protocol was further demonstrated by 2 mmol scale synthesis one example its elaboration other potentially useful building blocks as well late-stage modification diverse array structurally complex bioactive molecules.

Language: Английский

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Ruthenium and Iodine Anion Cocatalyzed Cascade Dihalogenation and Cyclization of Internal Alkyne-Tethered Cyclohexadienones with 1,2-Dihaloethanes

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(13), P. 9686 - 9694

Published: June 22, 2024

We have established an efficient ruthenium(II) and iodine anion cocatalyzed dihalogenation cascade cyclization of internal alkyne-tethered cyclohexadienones, which stereoselectively afforded numerous products with a bioactive hydrobenzofuran skeleton in high yields under mild conditions. In this transformation, the reaction pathway was determined by concentration electrophilic reagent, also provided strategy for control selectivity. Furthermore, method features use 1,2-dihaloroethane as halogen source via catalyst.

Language: Английский

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Stereoselective Double Spirocyclization of 2-Benzyl-3-alkynyl Chromone with Nitrone via Gold-Catalyzed Cascade Reactions

Organic Letters, Journal Year: 2024, Volume and Issue: 26(31), P. 6675 - 6680

Published: July 25, 2024

A novel, highly stereoselective gold-catalyzed spirocyclization of 2-benzyl-3-alkynyl chromone with nitrone is described. This cascade reaction involves cycloisomerization, nitrone-olefin [3 + 2]-annulation, alkene oxidation, and rearrangement for the formation spirocyclic products. Interestingly, isoxazolidine ring generated from 2]-annulation donates oxygen to generate a new pyran-3(4

Language: Английский

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Gold(I)-Catalyzed Rautenstrauch/Hetero-Diels–Alder/Retro-aza-Michael Cascade Reaction for the Synthesis of α-Hydrazineyl-2-cyclopentenones

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 12, 2024

A one-pot synthesis of ring-fused, α-hydrazineyl-2-cyclopentenone derivatives is achieved by a gold(I)-catalyzed Rautenstrauch/hetero Diels-Alder/ring opening tandem reaction suitable propargyl esters. By mixing the latter with dialkylazodicarboxylate in presence gold(I) catalyst, 1,2-acyloxy migration/cyclization process (Rautenstrauch reaction) leads to cyclopentadienyl ester intermediates which are trapped heterodienophile present situ. This provides strained spontaneously undergo highly regioselective ring retro aza-Michael promoted eventually yielding target compounds. Six- and seven-membered ring-fused cyclopentenones bearing pendant α-hydrazineyl moiety can be obtained moderate excellent yield (50-98%) this approach, minimal erosion initial optical purity when using enantioenriched substrates.

Language: Английский

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DFT Investigation on Palladium-Catalyzed [2 + 2 + 1] Spiroannulation between Aryl Halides and Alkynes: Mechanism, Base Additive Role, and Solvent and Ligand Effects

The Journal of Physical Chemistry A, Journal Year: 2024, Volume and Issue: 128(42), P. 9135 - 9145

Published: Oct. 11, 2024

Transition metal-catalyzed spiroannulations are practical strategies for constructing spirocyclic skeletons of pharmaceutical and biological significance, yet the microscopic mechanism still lacks in-depth explorations. Here, palladium-catalyzed [2 + 2 1] spiroannulation between aryl halides alkynes was studied by employing density functional theory (DFT) method. Based on comprehensive explorations a couple possible reaction pathways, it is found that probably experiences C-I oxidative addition, alkyne migration insertion, Cs

Language: Английский

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