Hexafluoroisopropanol (HFIP) as a Multifunctional Agent in Gold-Catalyzed Cycloisomerizations and Sequential Transformations

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(13), P. 8845 - 8860

Published: June 20, 2023

Despite the unique position of gold catalysis in contemporary organic synthesis, this area research is notorious for requiring activators and/or additives that enable by generating cationic forms catalysts. Cycloisomerization reactions occupy a significant portion gold-catalyzed reaction space, while they represent diverse family are frequently utilized synthesis. Herein, hexafluoroisopropanol (HFIP) shown to be uniquely simple tool cycloisomerizations, rendering use external obsolete and leading highly active catalytic systems with ppm levels catalyst loading certain cases. HFIP assumes dual role as solvent an activator, operating via dynamic activation Au–Cl bond through hydrogen bonding, which initiates cycle. This special mode can efficient scalable cyclization propargylamides ynoic acids [AuCl(L)] complexes. A thorough screening ancillary ligands counter anions has been performed, establishing methodology alternative elaborate ligand/catalyst design activators. Additionally, concept applied C–C bond-forming cycloisomerization 2H-chromenes sequential or one-pot transformations activated ketoesters, functionalized N-heterocyclic carbene (NHC) precursor salt, compound bearing bioactive indole core, among others. Importantly, mechanistic investigations, including "snapshot" species interest solid state, we were able unambiguously detect key H-bonding interaction between catalyst, shedding light on intermolecular enables catalysis. In cases examined herein, not only excellent but also potent activator valuable synthetic handle when incorporated into functional groups products.

Language: Английский

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Enantioselective Synthesis of 1-Dihydrobenzazepines through Rh₂(II)-Catalyzed Cycloisomerization of 1,6-Enyne

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: March 13, 2025

The 1-dihydrobenzazepine skeleton has emerged as a privileged structural motif in bioactive molecules. However, due to lack of asymmetric methodology, access chiral 1-dihydrobenzazepines remained limited. Herein, we report the first intermolecular cycloisomerization benzo-fused enynes for synthesis via dirhodium catalysis. This methodology features high efficiency (up 98% yield), enantioselectivity 99% ee), and broad scope nucleophiles, including oxygen nucleophiles (alcohols, phenols, carboxylic acids) carbon (silyl enol ethers). Theoretical experimental mechanistic studies reveal that reaction pathway encompasses an cycloisomerization, which gives rise carbene containing donor–acceptor (D-A) cyclopropane moiety, followed by ring-opening process stereoselective nucleophilic attack external on cyclopropyl ring. Control experiments demonstrate pivotal role terminal group capped alkynyl substrates achieving good efficiency.

Language: Английский

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Homogeneous Gold Catalysis: Development and Recent Advances

Chemistry - An Asian Journal, Journal Year: 2025, Volume and Issue: unknown

Published: April 28, 2025

Abstract Gold catalysis has witnessed remarkable advances over the past decade, with numerous insightful reviews chronicling this progress. However, a comprehensive review addressing developments in field during post‐pandemic COVID era remains notably absent. This aims to bridge that gap by providing an in‐depth analysis of recent studies, shedding light on unique properties gold complexes, particularly intriguing aurophilic interactions distinguish chemistry. The systematically explores latest achievements both mono‐ and dinuclear gold‐catalyzed reactions, focus their applications diverse fields, including redox coupling, asymmetric catalysis, photo‐, electrocatalysis. A special emphasis is placed comparative performance catalysts, latter often exhibiting enhanced catalytic efficiency selectivity certain reactions. By integrating mechanistic insights DFT perspectives representative experimental studies from years, highlights significance synthetic chemistry, identifies emerging trends outlines future directions for field.

Language: Английский

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Homogeneous Gold Catalysis for Regioselective Carbocyclization of Alkynyl Precursors

ChemPlusChem, Journal Year: 2023, Volume and Issue: 88(7)

Published: June 7, 2023

Abstract π‐Activation of alkynyl precursors possessing an endogenous carbon nucleophile is one the imperative topics in homogeneous gold catalysis as it offers Csp 3 ‐Csp 2 and linked carbocycles. However, exo ‐ dig endo cyclization modes unlocks possibility both small large rings respectively, thereby losing regioselectivity. Nevertheless, several gold‐catalyzed carbocyclizations which permits isomer by controlling or avoiding formation other went largely unnoticed. Hence, this review attempt to summarize such approaches reported from early 2000’s till date along with our viewpoint on contributing parameters for This covers only unimolecular reactions classifications primarily based type nucleophiles silyloxyenols, enamides/enamines, benzenoids, heteroaromatics alkyls/alkenyls. From application perspective, these are significant total synthesis materials science. Therefore, those that finds natural product π‐functional highlighted appropriate places.

Language: Английский

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1,4-Dihydropyrrolo[3,2-b]pyrroles with Two Embedded Heptagons via Alkyne Annulation

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

Published: Dec. 31, 2024

Drastic changes to the character of acidic catalyst enable reversal double alkyne benzannulation reaction output. In presence a strong Brønsted acid, 1,4-dihydropyrrolopyrroles undergo transformation which results in formation two 7-membered rings. Computational studies imply that thermodynamically unfavored ring is forged via kinetically favored 6-endo-dig attack protonated at position 3a pyrrolopyrrole followed by 1,2-vinyl shift.

Language: Английский

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Palladium-catalyzed [4 + 3]-annulations of oxotryptamines with allyl dicarbonates: an approach toward spiro[azepane-4,3′-oxindoles]

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(18), P. 4593 - 4597

Published: Jan. 1, 2023

A palladium-catalyzed tandem allylic substitution of oxotryptamines with allyl dicarbonates has been developed, affording spiro[azepane-4,3′-oxindoles] in moderate to excellent yields (30%–96%) up >20 : 1 Z -stereoselectivity.

Language: Английский

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Electrochemical Synthesis of 3-(Sulfonyl)quinol-4-ones from o-Alkynyl-N-(formyl)anilides and Sulfinates

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 25, 2024

Electrolysis of o-alkynyl-N-(formyl)anilides and sodium sulfinates on graphite electrodes delivers biologically sound 3-(sulfonyl)quinol-4-ones with moderate to good yields. The reaction is carried out in an undivided cell the presence silver(I) oxide potassium iodide or tetrafluoroborate as supporting electrolyte. tolerates variously substituted anilides well aryl alkyl sulfinates. transformation proceeds a domino sequence oxysulfonylation cyclocondensation steps.

Language: Английский

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