Fluorinated liquid crystals: evaluation of selectively fluorinated facially polarised cyclohexyl motifs for liquid crystal applications

Herein, we report a versatile approach for the endocyclic ring opening of bicyclic vinylcyclopropanes triggered by Heck arylations. The key step for this transformation is a β-C-elimination allowing the ring expansion of cyclopropanated pyrroles, piperidines, furans, as well as cyclopentadienes to grant access to the corresponding 1,2-dihydropyridines, 2H-pyrans, 2,3-dihydro-1H-azepines, and 1,4-cyclohexadienes, respectively. Additionally, gem-disubstituted cyclopropanated furans showed unexpected behavior by giving diastereoselectively asymmetrically substituted dienes. Mechanistic studies and theoretical calculations point toward a facile β-C-elimination with a concomitant shift of Pd along the cyclopropane moiety, which can successfully compete with the usual termination step of a Heck reaction via a syn-β-hydride elimination.

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“…Stereochemistry of compounds 25 and 27 could not be determined. Trans-selectivity was tentatively assigned in analogy to the literature …”

Section: Resultsmentioning

confidence: 99%

Heck-Type Coupling of Fused Bicyclic Vinylcyclopropanes: Synthesis of 1,2-Dihydropyridines, 2,3-Dihydro-1H-azepines, 1,4-Cyclohexadienes, and 2H-Pyrans

et al. 2021

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“…A possibility of modification at the phenyl ring of the obtained products was demonstrated. [283,285] In particular, iodination of 414 was the key step in the synthesis of amino acids and peptides bearing an all-cis-2,3,5,6-tetrafluorocyclohexyl substituent. [286] Unfortunately, oxidation of the phenyl ring to install the COOH moiety did not work, but the unwanted side reactions could be blocked by introducing methyl group or fluorine atom at the α position (see Scheme 105).…”

Section: Synthesis Of Other Fluorinated Cycloalkyl Building Blocksmentioning

confidence: 99%

Fluorinated Cycloalkyl Building Blocks for Drug Discovery

et al. 2022

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The review covers various aspects of fluorinated cycloalkyl (C3−C7) building blocks for drug discovery, including their synthesis, key physicochemical properties, and biological and medicinal applications of their derivatives. The discussed synthetic methods include classical nucleophilic fluorinations of various substrates, the addition of fluorine and another heteroatom to double bonds, cycloadditions and other transformations of fluorine‐containing substrates, as well as some newer reactions like fluorination of non‐activated and remotely activated C−H bonds, decarboxylative and deborylative fluorinations, etc. The known data on the effect of introducing the fluorinated cycloalkyl groups on the compound's key in vitro parameters (such as acidity/basicity, lipophilicity, conformational behavior, and short contact capabilities) are surveyed. Finally, applications of fluorinated cycloalkyl building block derivatives in the design of biologically active compounds (including marketed drugs Maraviroc, Ivosidenib, and Sitafloxacin) are covered, with a focus on the fluorination impact.

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“…For instance, nearly a quarter of the currently manufactured agrochemical and pharmaceutical products contains at least one fluorine atom [6][7][8]. Fluorinated functional materials have also found wide application as durable ion exchange membranes, e.g., in fuel cells [9][10][11], as thermoplastic polymers [12][13][14], in electronic and optoelectronic technologies [15], and in liquid crystal display applications [16][17][18][19][20][21], etc [22]. The use of fluorinated building blocks is a very convenient approach and in many cases represents an indispensable alternative to late-stage fluorinations in the preparation of such unique materials [23].…”

Section: Introductionmentioning

confidence: 99%

Diels–Alder reaction of β-fluoro-β-nitrostyrenes with cyclic dienes

Ponomarev¹,

Larkovich²,

Aldoshin³

et al. 2021

Beilstein J. Org. Chem.

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The Diels–Alder reaction of β-fluoro-β-nitrostyrenes with cyclic 1,3-dienes was investigated. A series of novel monofluorinated norbornenes was prepared in up to 97% yield. The reaction with 1,3-cyclohexadiene permits the preparation of monofluorinated bicyclo[2.2.2]oct-2-enes. The kinetic data of the reactions with 1,3-cyclopentadiene and 1,3-cyclohexadiene were used to calculate activation parameters. Furthermore, the synthetic utility of the cycloadducts obtained was demonstrated.

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Fluorinated liquid crystals: evaluation of selectively fluorinated facially polarised cyclohexyl motifs for liquid crystal applications

Abstract: A series of prototype negative dielectric liquid crystalline (LC) compounds which contain the facially polarised all cis-fluorinatedcyclohexane motifs is explored.

Cited by 14 publications

References 28 publications

Heck-Type Coupling of Fused Bicyclic Vinylcyclopropanes: Synthesis of 1,2-Dihydropyridines, 2,3-Dihydro-1H-azepines, 1,4-Cyclohexadienes, and 2H-Pyrans

Heck-Type Coupling of Fused Bicyclic Vinylcyclopropanes: Synthesis of 1,2-Dihydropyridines, 2,3-Dihydro-1H-azepines, 1,4-Cyclohexadienes, and 2H-Pyrans

Fluorinated Cycloalkyl Building Blocks for Drug Discovery

Diels–Alder reaction of β-fluoro-β-nitrostyrenes with cyclic dienes

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