A general approach to arylated furans, pyrroles, and thiophenes

Polyynes are linear carbon rods that may be regarded as models of carbyne – still elusive linear allotropic form of carbon. This microreview addresses the use of polyynes as synthetic precursors of complex organic and organometallic compounds. Application of such unusual molecules as starting materials for various chemical transformations leads to products which often are not easily accessible using “traditional“ approaches. Polyynes may for instance be used in the synthesis of molecular wires, materials possessing high nonlinear optical response, complex donor–acceptor systems, solvatochromic fluorescent dyes or natural products. The most significant challenge here is to control the regioselectivity of a transformation of such linear sp‐hybridized carbon chains. The impact of steric and electronic properties of reagents on the reaction pattern is hence highly important and will be discussed. Moreover, the transformations of end‐groups will also be addressed since their reactivity might very often be different than that of acetylenes.

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“…[75][76][77] Such transformation may be also applied for polyynes. [75][76][77] Such transformation may be also applied for polyynes.…”

Section: Formation Of Heterocyclesmentioning

confidence: 99%

Reactivity of Polyynes: Complex Molecules from Simple Carbon Rods

2019

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“…[1,2] To date, there are no examples in the known literature for which postcyclization transformations of the 1,3-diyne linker of a macrocyclic peptide have been applied. [7] The reaction of 1,3-diynes with S-nucleophiles can lead to thioenynes or thiophenes, [8][9][10][11][12][13][14][15][16] and analogous hydration or hydroamination reactions give rise to furans [15][16][17][18] or pyrroles. 1,3-Diynes have for a long time been considered as versatile building blocks, [6] and currently, they are receiving revived interest in organic synthesis.…”

Section: Introductionmentioning

confidence: 99%

“…1,3-Diynes have for a long time been considered as versatile building blocks, [6] and currently, they are receiving revived interest in organic synthesis. [7] The reaction of 1,3-diynes with S-nucleophiles can lead to thioenynes or thiophenes, [8][9][10][11][12][13][14][15][16] and analogous hydration or hydroamination reactions give rise to furans [15][16][17][18] or pyrroles. [12,15,[17][18][19][20] Unfortunately, in many cases a high reaction temperature is needed, and these transformations are mostly reported by using arylated 1,3-diynes.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Heterocycle‐Bridged Peptidic Macrocycles through 1,3‐Diyne Transformations

2016

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Macrocyclic tetrapeptide analogues containing a 1,3‐diyne moiety were synthesized by a Glaser–Hay‐type macrocyclization. The obtained 1,3‐diyne was evaluated as a handle to introduce heterocycles into the macrocyclic structure. It was shown that the macrocyclic 1,3‐diynes were successfully transformed into various heterocycles by nucleophilic attack of (bis)nucleophiles to the diyne moiety. Treatment with NaHS or H2O as nucleophiles gave rise to 2,5‐bridged thiophenes or furans, whereas the use of hydrazines and hydroxylamine gave rise to the corresponding pyrazole‐ and isoxazole‐containing macrocycles. In addition, a thermoreversible Diels–Alder cycloaddition of a cyclopeptidic bridged furan was demonstrated.

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“…[21] A general and practical transition metal-free synthetic method for aryl-substituted 5-membered heterocycles has been developed. [22] In the presence of KOH (30%), 1,4-diaryl-1,3-butadiynes undergo the cyclocondensation reaction with water, primary amines, and Na 2 S·9H 2 O in DMSO at 80°C to afford 2,5-diarylfurans, 1,2,5-trisubstituted pyrroles, and 2,5-diarylthiophenes in good to high yields. An efficient and straightforward 1-pot strategy for the synthesis of 4,5-dihydropyrazole derivatives from ketones, arylacetylenes, and hydrazines in the presence of KO t Bu/DMSO provides a flexible and rapid route to polysubstituted 4,5-dihydropyrazoles.…”

mentioning

confidence: 99%

Exploring acetylene chemistry in superbasic media: A theoretical study of the effect of water on vinylation and ethynylation reactions with acetylene in KOH/DMSO and NaOH/DMSO systems

Vitkovskaya

Orel

Кобычев

et al. 2016

J. Phys. Org. Chem.

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A rapidly developing approach adding new dimensions to acetylene chemistry relying on employment of high basicity media such as alkali metal hydroxide suspensions in dimethyl sulfoxide (DMSO) has been, for the first time, investigated theoretically using ab initio models. Extending our recently introduced model of superbase catalysis with a nondissociated KOH (or NaOH) participation, we present here a model for a superbasic reaction center with the first solvation shell explicitly included. The alkali metal hydroxides in a DMSO solution were found to form KOH·5DMSO and NaOH·4DMSO complexes that are stabilized due to the interligand interaction. Our present MP2/6‐311++G**//B3LYP/6‐31+G* computations show that 1 and 2 water molecules can build themselves into the MOH close surrounding without substantially perturbing the DMSO ligands and easily travel between different insertion positions. Our results predict that the activation energies in the series of reactions of nucleophilic addition to a triple bond with water, methanol, methanethiol, sodium hydrosulfide, and acetone in the presence of dihydrated complexes should be larger than those obtained with the participation of monohydrated ones, which is in fair agreement with the experimental findings. The present model also explains an increase in the ethynylation reaction yield in the presence of water by suppression of the competitive enolization reaction.

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A general approach to arylated furans, pyrroles, and thiophenes

Cited by 54 publications

References 33 publications

Reactivity of Polyynes: Complex Molecules from Simple Carbon Rods

Reactivity of Polyynes: Complex Molecules from Simple Carbon Rods

Synthesis of Heterocycle‐Bridged Peptidic Macrocycles through 1,3‐Diyne Transformations

Exploring acetylene chemistry in superbasic media: A theoretical study of the effect of water on vinylation and ethynylation reactions with acetylene in KOH/DMSO and NaOH/DMSO systems

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