Gold‐Catalyzed Formal Cyclisation/Dimerization of Thiophene‐Tethered Diynes

Tšupova, Svetlana; Hansmann, Max M.; Rudolph, Matthias; Röminger, Frank; Hashmi, A. Stephen K.

doi:10.1002/chem.201700061

Cited by 14 publications

(8 citation statements)

References 59 publications

(18 reference statements)

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“…The gold-catalyzed cascade did not provide the expected V (H); instead, a compound was isolated with a structure that was suggested to be 13 . Such dimerized side products have been reported under the applied conditions and were associated with the presence of terminal alkynes …”

Section: Resultsmentioning

confidence: 72%

“…Such dimerized side products have been reported under the applied conditions and were associated with the presence of terminal alkynes. 46 To eliminate the side reaction, we synthesized a benzothiophene derivative with two phenylacetylene moieties. For this, benzothiophene (14) was dibrominated with Br 2 , then product 15 was coupled with two equivalents of phenylacetylene.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Unsymmetrical Thienopentalenes: Synthesis, Optoelectronic Properties, and (Anti)aromaticity Analysis

et al. 2022

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The synthesis and properties of a series of unsymmetrical thienopentalenes are explored, including both monoareno and diareno derivatives. For the synthesis of monoareno pentalenes, a carbopalladation cascade reaction between alkynes and gem-dibromoolefins was applied. Diareno pentalene derivatives were accessed via gold-catalyzed cyclization of diynes. Thiophene was fused to pentalene in two different geometries via its 2,3 and 3,4 bonds. 2,3-Fusion resulted in increased antiaromaticity of the pentalene unit compared to the 3,4-fusion both in the monoareno and diareno framework. Monothienopentalenes that contained the destabilizing 2,3-fusion could not be isolated. For diareno derivatives, the aromatic character of the different aryl groups fused to the pentalene was not independent. Destabilizing fusion on one side resulted in alleviated aromaticity on the other side and vice versa. The synthesized molecules were characterized experimentally by 1H NMR and UV–vis spectroscopies, cyclic voltammetry, and X-ray crystallography, and their aromatic character was assessed using magnetic (NICS and ACID) and electronic indices (MCI and FLU).

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Section: Resultsmentioning

confidence: 72%

Section: ■ Results and Discussionmentioning

confidence: 99%

Unsymmetrical Thienopentalenes: Synthesis, Optoelectronic Properties, and (Anti)aromaticity Analysis

et al. 2022

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“…[293] Likewise, thienyl-2,3-diynes devoid of any γ-CÀ H bond did not undergo late-stage CÀ H annulation under dual-gold catalysis and exhibited only a formal cycliza-tion/dimerization cascade. [294] This reactivity pattern was in sharp contrast to the related 1,2-dialkynylbenzenes having no γ-CÀ H bonds (as shown in Scheme 59, Eq. (2), which underwent both cyclization as well as CÀ H annulation, [276] This divergence in reaction course points to the importance of the benzene ring (vs. thiophene) for further CÀ H annulation step.…”

Section: Hydroarylation Of Enyne and Diyne Surrogatesmentioning

confidence: 90%

“…It is noteworthy that these substrates generate strained cyclobutyl derivatives as a consequence of domino 6‐ endo ‐ dig cyclization/β‐Csp 3 −H insertion [293] . Likewise, thienyl‐2,3‐diynes devoid of any γ‐C−H bond did not undergo late‐stage C−H annulation under dual‐gold catalysis and exhibited only a formal cyclization/dimerization cascade [294] . This reactivity pattern was in sharp contrast to the related 1,2‐dialkynylbenzenes having no γ‐C−H bonds (as shown in Scheme 59, Eq.…”

Section: Hydroarylation Of Enyne and Diyne Surrogatesmentioning

confidence: 99%

Catalytic Gold Chemistry: From Simple Salts to Complexes for Regioselective C−H Bond Functionalization

Praveen

Dupeux

Michelet

2021

Chemistry A European J

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Gold coordinated to neutral phosphines (R 3 P), Nheterocyclic carbenes (NHCs) or anionic ligands is catalytically active in functionalizing various CÀ H bonds with high selectivity. The sterics/electronic nature of the studied CÀ H bond, oxidation state of gold and stereoelectronic capacity of the coordinated auxiliary ligand are some of the associated selectivity factors in gold-catalyzed CÀ H bond functionalization reactions. Hence, in this review a comprehensive update about the action of different types of gold catalysts, from simple to sophisticated ones, on CÀ H bond reactions and their regiochemical outcome is disclosed. This review also highlights the catalytic applications of Au(I)-and Au(III)species in creating new opportunities for the regio-and siteselective activation of challenging CÀ H bonds. Finally, it also intends to stress the potential applications in selective CÀ H bond activation associated with a variety of heterocycles recently described in the literature.

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“…The reactivity pattern of 1, n -diynes has also been smartly exploited toward the construction of complex highly π-conjugated polycyclic systems (Asiri and Hashmi, 2016). In this sense, the works from Hashmi stand out with several remarkable publications on this topic in the last years (Tšupova et al, 2017; Wurm et al, 2017, 2018). A representative example is shown in Figure 15A.…”

Section: Gold-catalyzed Isomerization Processes Involving An Initimentioning

confidence: 96%

Gold-Catalyzed Homogeneous (Cyclo)Isomerization Reactions

2019

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Gold is currently one of the most used metals in organometallic catalysis. The ability of gold to activate unsaturated groups in different modes, together with its tolerance to a wide range of functional groups and reaction conditions, turns gold-based complexes into efficient and highly sought after catalysts. Natural products and relevant compounds with biological and pharmaceutical activity are often characterized by complex molecular structures. (Cyclo)isomerization reactions are often a useful strategy for the generation of this molecular complexity from synthetically accessible reactants. In this review, we collect the most recent contributions in which gold(I)- and/or gold(III)-catalysts mediate intramolecular (cyclo)isomerization transformations of unsaturated species, which commonly feature allene or alkyne motifs, and organize them depending on the substrate and the reaction type.

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Gold‐Catalyzed Formal Cyclisation/Dimerization of Thiophene‐Tethered Diynes

Cited by 14 publications

References 59 publications

Unsymmetrical Thienopentalenes: Synthesis, Optoelectronic Properties, and (Anti)aromaticity Analysis

Unsymmetrical Thienopentalenes: Synthesis, Optoelectronic Properties, and (Anti)aromaticity Analysis

Catalytic Gold Chemistry: From Simple Salts to Complexes for Regioselective C−H Bond Functionalization

Gold-Catalyzed Homogeneous (Cyclo)Isomerization Reactions

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