Cobalt-Catalyzed Glaser-type Homocoupling Reaction

Ye, Ke‐Yin; Han, Jun-Fa; Guo, Peng; Chen, Lin

doi:10.1055/a-1711-6097

Cited by 2 publications

(3 citation statements)

References 49 publications

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“…Since the pioneering work by Glaser in 1869 [ 30 ], Glaser coupling and its modifications have become one of the most widely utilized and powerful strategies for the synthesis of diverse 1,3-dialkynes [ 31 , 32 , 33 , 34 ]. Numerous metal catalytic systems such as palladium [ 35 , 36 ], cobalt [ 37 , 38 ], ruthenium [ 39 ], and gold, etc., [ 40 , 41 , 42 ] have been studied on this reaction. However, most of their wide applications are limited because of their higher price or instability in air.…”

Section: Introductionmentioning

confidence: 99%

A Simple and Practical Bis-N-Heterocyclic Carbene as an Efficient Ligand in Cu-Catalyzed Glaser Reaction

et al. 2023

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Conjugated diyne derivatives are important scaffolds in modern organic synthetic chemistry. Using the Glaser reaction involves the coupling of terminal alkynes which can efficiently produce conjugated diyne derivatives, while the use of a stoichiometric amount of copper salts, strong inorganic base, and excess oxidants is generally needed. Developing an environmentally friendly and effective method for the construction of symmetrical 1,3-diynes compounds by Glaser coupling is still highly desirable. In this study, we present an economical method for the production of symmetric diynes starting from various terminal acetylenes in a Glaser reaction. A simple and practical bis-N-heterocyclic carbene ligand has been introduced as efficient ligands for the Cu-catalyzed Glaser reaction. High product yields were obtained at 100 °C for a variety of substrates including aliphatic and aromatic terminal alkynes and differently substituted terminal alkynes including the highly sterically hindered substrate 2-methoxy ethynylbenzene or 2-trifluoromethyl ethynylbenzene and a series of functional groups, such as trifluoromethyl group, ester group, carboxyl group, and nitrile group. The established protocol is carried out in air under base-free condition and is operationally simple. These research work suggest that bis-N-heterocyclic carbene could also an appealing ligand for Glaser reaction and provide a reference for the preparation of symmetric 1,3-diynes in industrial filed.

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Section: Introductionmentioning

confidence: 99%

A Simple and Practical Bis-N-Heterocyclic Carbene as an Efficient Ligand in Cu-Catalyzed Glaser Reaction

et al. 2023

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“…While the majority of these reports employ a copper complex as a catalyst, some other earth abundant metal complexes have also shown their potential on promoting Glaser–Hay homocoupling reactions. Thus, Hilt has reported the CoBr 2 ‐catalysed coupling of terminal alkynes using nitrobenzene as a stoichiometric oxidant under reductive conditions, [8] and more recently Ye has described the use of Co(salen) complexes (salen= N,N’ ‐ethylenebis(salicylimine)) to catalyse these reactions employing di‐ tert ‐butyldiaziridinone [9] …”

Section: Introductionmentioning

confidence: 99%

“…Thus, Hilt has reported the CoBr 2 -catalysed coupling of terminal alkynes using nitrobenzene as a stoichiometric oxidant under reductive conditions, [8] and more recently Ye has described the use of Co(salen) complexes (salen = N,N'-ethylenebis(salicylimine)) to catalyse these reactions employing di-tert-butyldiaziridinone. [9] Within manganese chemistry, seminal work by Cahiez has shown that mixed-metal salts such as MnCl 2 • 2 LiCl can catalyse homocoupling of Grignard reagents, including alkynyl-substituted RMgX, using oxygen as oxidant. [10] More recently, Taillefer has also demonstrated that in situ generated Li-aryls and Liacetylides can undergo homocoupling in the presence of air using catalytic amounts of MnCl 2 .…”

Section: Introductionmentioning

confidence: 99%

Structural and Synthetic Insights on Oxidative Homocouplings of Alkynes Mediated by Alkali‐Metal Manganates

Mastropierro

Platten

Kennedy

et al. 2023

Chemistry A European J

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Exploiting bimetallic cooperation alkali‐metal manganate (II) complexes can efficiently promote oxidative homocoupling of terminal alkynes furnishing an array of conjugated 1,3‐diynes. The influence of the alkali‐metal on these C−C bond forming processes has been studied by preparing and structurally characterizing the alkali‐metal tetra(alkyl) manganates [(TMEDA)2Na2Mn(CH2SiMe3)4] and [(PMDETA)2K2Mn(CH2SiMe3)4]. Reactivity studies using phenylacetylene as a model substrate have revealed that for the homocoupling to take place initial metalation of the alkyne is required. In this regard, the lack of basicity of neutral Mn(CH2SiMe3)2 precludes the formation of the diyne. Contrastingly, the tetra(alkyl) alkali‐metal manganates behave as polybasic reagents, being able to easily deprotonate phenylacetylene yielding [{(THF)4Na2Mn(C≡CPh)4}∞] and [(THF)4Li2Mn(C≡CPh)4]. Controlled exposure of [{(THF)4Na2Mn(C≡CPh)4}∞] and [(THF)4Li2Mn(C≡CPh)4] to dry air confirmed their intermediary in formation of 1,4‐diphenyl‐1,3‐butadiyne in excellent yields. While the Na/Mn(II) partnership proved to be the most efficient in stoichiometric transformations, under catalytic regimes, the combination of MC≡CAr (M= Li, Na) and MnCl2 (6 mol %) only works for lithium, most likely due to the degradation of alkynylsodiums under the aerobic reaction conditions.

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Cobalt-Catalyzed Glaser-type Homocoupling Reaction

Cited by 2 publications

References 49 publications

A Simple and Practical Bis-N-Heterocyclic Carbene as an Efficient Ligand in Cu-Catalyzed Glaser Reaction

A Simple and Practical Bis-N-Heterocyclic Carbene as an Efficient Ligand in Cu-Catalyzed Glaser Reaction

Structural and Synthetic Insights on Oxidative Homocouplings of Alkynes Mediated by Alkali‐Metal Manganates

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