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

ACS Catalysis, Год журнала: 2023, Номер 13(13), С. 8845 - 8860

Опубликована: Июнь 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.

Язык: Английский

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Difunctionalization Processes Enabled by Hexafluoroisopropanol

ACS Organic & Inorganic Au, Год журнала: 2024, Номер 4(3), С. 287 - 300

Опубликована: Март 4, 2024

In the past 5 years, hexafluoroisopropanol (HFIP) has been used as a unique solvent or additive to enable challenging transformations through substrate activation and stabilization of reactive intermediates. this Review, we aim at describing difunctionalization processes which were unlocked when HFIP was involved. Specifically, focus on cyclizations additions alkenes, alkynes, epoxides, carbonyls that introduce wide range functional groups interest.

Язык: Английский

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Hexafluoroisopropanol Promoted Ring‐Opening‐Cyclization of Donor–Acceptor Cyclopropanes with Primary Amines

European Journal of Organic Chemistry, Год журнала: 2024, Номер 27(22)

Опубликована: Март 19, 2024

Abstract We reveal here a catalyst‐free, ring‐opening‐cyclization of donor‐acceptor cyclopropanes with primary amines to synthesize functionalized dihydropyrroles. This protocol avoids inert conditions and solvents promoted by hexafluoroisopropanol (HFIP). The reaction is quite general aryl, alkyl, alicyclic amines. A good number bearing keto groups reacted excellently produce the desired products. Further, we complemented this method Meldrum's acid‐derived for synthesizing γ‐lactams. have demonstrated post‐synthetic applications products gram‐scale synthesis highlight adaptability synthetic protocol.

Язык: Английский

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Mechanochemical Cascade Cyclization of Cyclopropyl Ketones with 1,2-Diamino Arenes for the Direct Synthesis of 1,2-Disubstituted Benzimidazoles

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(13), С. 9427 - 9439

Опубликована: Июнь 21, 2024

A mechanochemical synthesis of 1,2-disubstituted benzimidazoles from donor-acceptor cyclopropyl ketones and 1,2-diaminoarenes under metal-free solventless conditions is reported. The reaction does not require inert promoted by a stoichiometric amount 1,1,1,3,3,3-hexafluoroisopropanol. This cascade involves ring-opening, cyclization, retro-Mannich with aryl 1,2-diamines. Compared to its solution-phase counterpart, this approach shows fast reactivity (24 vs 1.5 h). Mechanistic investigations electrospray ionization mass spectrometry helped us propose the mechanism.

Язык: Английский

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Catalytic Enantioselective Synthesis of Difluoromethylated Tetrasubstituted Stereocenters in Isoindolones Enabled by a Multiple-Fluorine System

Organic Letters, Год журнала: 2020, Номер 22(22), С. 9010 - 9015

Опубликована: Ноя. 4, 2020

A poly trifluoromethylated chiral spirocyclic phosphoric acid was developed and employed with hexafluoroisoproyl alcohol (HFIP) to render the catalytic asymmetric Mukaiyama-Mannich reaction of difluoroenoxysilanes in situ formed ketimines. This unique multiple-fluorine system provides rapid access difluoromethylated tetrasubstituted stereocenters isoindolones wide substrate scope under mild conditions. Further synthetic transformations enantioenriched CF2H-isoindolones CF2-decorated fused were also implemented good efficiency.

Язык: Английский

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Rapid and Mild Metal-Free Reduction of Epoxides to Primary Alcohols Mediated by HFIP

ACS Catalysis, Год журнала: 2022, Номер 12(6), С. 3309 - 3316

Опубликована: Фев. 25, 2022

The reduction of epoxides is a powerful tool to access anti-Markovnikov alcohols, but reported methods are poorly compatible with strongly electronically deactivated substrates. Here, we describe general method for the linear-selective styryl oxides incorporating strong electron-withdrawing groups. remains more traditional epoxide motifs, such as aliphatic and electron-rich styrene oxides. Other (hetero)cycles oxetanes, tetrahydrofurans, aziridines, cyclopropanes can also be reductively opened. This user-friendly reaction relies on combination Brønsted acid catalyst hexafluoroisopropanol solvent, thus, in contrast existing methods, it does not require anhydrous reagents or an inert atmosphere. generated primary alcohols conveniently functionalized situ by dehydrative Friedel–Crafts arylation without preactivation.

Язык: Английский

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Fluorinated Alcohol-Processed N-Type Organic Electrochemical Transistor with High Performance and Enhanced Stability

ACS Applied Materials & Interfaces, Год журнала: 2022, Номер 14(38), С. 43586 - 43596

Опубликована: Сен. 16, 2022

Tuning the film morphology and aggregated structure is a vital means to improve performance of mixed ionic-electronic conductors in organic electrochemical transistors (OECTs). Herein, three fluorinated alcohols (FAs), including 2,2,2-trifluoroethanol (TFE), 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), perfluoro-tert-butanol (PFTB), were employed as alternative solvents for engineering n-type small-molecule active layer gNR. Remarkedly, an impressive μC* 5.12 F V-1 cm-1 s-1 normalized transconductance 1.216 S are achieved from HFIP-fabricated gNR OECTs, which times higher than that chloroform. The operational stability has been significantly enhanced by FA-fabricated devices. Such enhancements can be ascribed aggregation-induced structural ordering FAs during spin coating, optimizes microstructure films better ion electron transport. These results prove huge research potential OECT materials' processability, device performance, stability, therefore promoting practical bio-applications.

Язык: Английский

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Hydride Transfer-Initiated Cross-Dehydrogenative Coupling Reaction to Access Nine-Membered Rings

Organic Letters, Год журнала: 2023, Номер 25(14), С. 2432 - 2437

Опубликована: Апрель 5, 2023

An unprecedented hydride transfer-triggered cross-dehydrogenative coupling of two C(sp3)-H bonds to target nine-membered rings has been developed. Salient features this methodology include atom and step economy metal-free redox-neutral conditions, with water as the byproduct proceeding well even decomposed aldehydes.

Язык: Английский

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Hydro-phosphorothiolation of Styrene and Cyclopropane with S-Hydrogen Phosphorothioates under Ambient Conditions

Organic Letters, Год журнала: 2024, Номер 26(24), С. 5141 - 5145

Опубликована: Июнь 7, 2024

A metal-free hexafluoroisopropanol-mediated hydro-phosphorothiolation of styrenes and donor-acceptor cyclopropanes with

Язык: Английский

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Synthesis of Fluorine-Containing Multisubstituted Oxa-Spiro[4,5]cyclohexadienones via a Fluorinated Alcohol-Catalyzed One-Pot Sequential Cascade Strategy

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(5), С. 2847 - 2857

Опубликована: Фев. 16, 2024

In recent years, the application of fluorinated alcohols as solvents, cosolvents, or additives has become important in modern organic synthesis. However, their potential efficient catalysts synthesis not been well-explored. this article, we report on development a one-pot sequential cascade reaction p-quinone methides with difluoroenoxysilanes using hexafluoroisopropanol catalyst. This allows for preparation multisubstituted oxa-spiro[4,5]cyclohexadienones. By 50 mol % 1,1,1,3,3,3-Hexafluoroisopropanol (HFIP), proceeds smoothly to yield 1,6-conjugated products, which are then subjected oxidative dearomatization/hemiacetalization PhI(OAc)2. The overall process affords moderate high yields and excellent diastereoselectivities.

Язык: Английский

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