Manganese- or Iron-Catalyzed Homocoupling of Grignard Reagents Using Atmospheric Oxygen as an Oxidant

Cahiez, Gérard; Moyeux, Alban; Buendia, Julien; Duplais, Christophe

doi:10.1021/ja075417k

Cited by 243 publications

(138 citation statements)

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“…www.chemeurj.org species is unlikely since the reaction occurred with similar yields in the presence of air [15] or acetic anhydride. [16] However, a radical pathway based on single-electron transfer (SET) cannot be ruled out.…”

Section: Entrymentioning

confidence: 99%

Direct Method for Carbon–Carbon Bond Formation: The Functional Group Tolerant Cobalt‐Catalyzed Alkylation of Aryl Halides

Amatore

Gosmini

2010

Chemistry A European J

108

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Dedicated to the memory of Professor Pascal Le Floch; an inspiring scientist and wonderful individualModern transition-metal-catalyzed reactions have been shown to be of indispensable value for organic synthesis. [1] In particular, the cross-coupling of alkyl halides, including problematic unactivated alkyl halides, have now emerged as promising candidates to complement and extend the scope of the traditional Friedel-Crafts alkylation. [2, 3] The incorporation of a new alkyl chain on an aromatic moiety often proceeds by the metal-catalyzed coupling of stoichiometric organometallic derivatives (alkyl-M or aryl-M, M = Zn, B, Si, Sn, Mg, Mn, In, Al) using a large variety of transition metals, such as palladium, nickel, iron, cobalt, copper, rhodium, manganese, vanadium, or even silver. [2,4] However, it is intriguing to consider a direct approach for cross-coupling that does not rely on the utilization of preformed organometallic reagents, thus resulting in reduced step count and waste. Two main strategies have been reported, the palladium-catalyzed CÀH activation for the domino ortho-alkylation/Heck coupling sequence, [5] and the direct cross-coupling of the corresponding halides.[6] The latter process involves a nickel-catalyzed activation of a-chlorocarbonyls for the synthesis of functionalized a-arylcarbonyl compounds. More recently, a magnesium-mediated direct cross-coupling using catalytic amounts of iron or cobalt salts has been developed by Jacobi von Wangelin and co-workers, thus documenting a practical alternative to the use of electrosynthesis or toxic nickel salts. [7] Despite the inherent practical advantages of these methods, the mechanistic fundament is the in situ formation of reactive Grignard reagents, which, in turn, narrows the substrate scope. The latter is generally restricted to electron-rich aryl and alkyl bromides and does not tolerate functional groups such as esters or ketones that are prone to react with organomagnesium reagents. We previously documented the development of straightforward procedures for the direct cobalt-catalyzed functionalization of aryl halides using CoBr 2 /ligand/metal systems.[8] Employing non-toxic cobalt salts, we discovered highly reactive catalyst systems suitable for inexpensive and operationally trivial carboncarbon bond-forming processes. Most importantly, these catalyst systems also showed compatibility with otherwise sensitive functionalized coupling partners. Herein, we report a versatile method for the direct functional group tolerant alkylation of aryl halides, a transformation that employs simple catalytic systems consisting of CoBr 2 /Ligand/Mn. Our new cross-coupling protocol proceeds smoothly in the presence of phosphanes or bipyridines as ligands with a variety of alkyl halides, including challenging alkyl electrophiles bearing b-hydrogen atoms. Though the reaction requires presently activated aryl halides, the synthetic scope is in our view largely compensated by the use of a simple catalyst formed in situ from ubiquitous reagents and by the fact ...

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Section: Entrymentioning

confidence: 99%

Direct Method for Carbon–Carbon Bond Formation: The Functional Group Tolerant Cobalt‐Catalyzed Alkylation of Aryl Halides

Amatore

Gosmini

2010

Chemistry A European J

108

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“…Therefore, as the reaction proceeds in the presence of Mn powder, we First, we showed that the reaction is not affected by the presence of air as oxidant since it is well known oxidants provoke the homocoupling of RÀMn derivatives. [10] Whatever the experimental conditions used (inert atmosphere or in air), reactions led to the same result in terms of kinetics and conversion yields. Second evidence was given when the reaction was run in the presence of acetic anhydride [17] since no ketone was produced.…”

mentioning

confidence: 92%

“…[1g] Conversely, symmetrical biaryls can also be synthesized by oxidative homocoupling of nucleophilic organometallic aryl derivatives ArM in the presence of an oxidant. This reaction which, in most cases, is catalyzed by palladium complexes [3g-6] was also developed with other metals such as nickel, [7] copper, [8] iron, [9] manganese, [10] gold [11] and cobalt. [12] Recently, the "transition-metal-free" homocoupling reaction of organomagnesium compounds has also been developed in the presence of a stoichiometric amount of an organic oxidant.…”

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confidence: 99%

Cobalt‐Catalyzed Formation of Symmetrical Biaryls and Its Mechanism

Moncomble¹,

Floch²,

Gosmini³

2009

Chemistry A European J

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Effective devotion: An efficient cobalt-catalyzed method devoted to the formation of symmetrical biaryls is described avoiding the preparation of organometallic reagents. Various aromatic halides functionalized by a variety of reactive group reagents are employed. Preliminary DFT calculations have shown that the involvement of a Co(I)/Co(III) couple is realistic at least in the case of 1,3-diazadienes as ligands (FG = functional group).

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“…Some base free Cumediated alkyne homocoupling reaction, have also been reported [14], and even neat processes have also been developed for oxidative homocoupling reaction of terminal alkynes [15]. The use of transition metals mediated homocoupling reactions other than Pd and Cu for the synthesis of 1, 3-diynes are still limited [16]. During the last decade gold salt and its complexes have played an emerging role for activation of C-C multiple bonds toward a variety of nucleophiles [17].…”

Section: Introductionmentioning

confidence: 99%

Gold Chloride (AuCl<sub>3</sub>) Catalyzed Expeditious Homocoupling of Terminal Alkynes at Ambient and Solvent Free Conditions: Impact of Sodium Acetate on the Reaction Yield

Farooq¹,

Dar²,

Tantaray³

et al. 2017

SJC

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Abstract:Homocoupling of terminal alkynes to 1, 3-diynes has been investigated, using AuCl 3 as catalyst under mild and operationally simple conditions. Effect of different organic and inorganic bases on the product yield and the reaction time were also studied. The catalyst is efficient, furnishes good to excellent yield of the desired products with organic bases and Sodium acetate was found to be the most effective base under solvent free conditions at room temperature.

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Manganese- or Iron-Catalyzed Homocoupling of Grignard Reagents Using Atmospheric Oxygen as an Oxidant

Abstract: Atmospheric oxygen was used for the first time as an oxidant in metal-catalyzed homocoupling of Grignard reagents. These manganese- or iron-catalyzed reactions are efficient, cheap, and eco-friendly. They are applicable to the large-scale synthesis of symmetrical conjugated compounds.

Cited by 243 publications

References 10 publications

Direct Method for Carbon–Carbon Bond Formation: The Functional Group Tolerant Cobalt‐Catalyzed Alkylation of Aryl Halides

Direct Method for Carbon–Carbon Bond Formation: The Functional Group Tolerant Cobalt‐Catalyzed Alkylation of Aryl Halides

Cobalt‐Catalyzed Formation of Symmetrical Biaryls and Its Mechanism

Gold Chloride (AuCl<sub>3</sub>) Catalyzed Expeditious Homocoupling of Terminal Alkynes at Ambient and Solvent Free Conditions: Impact of Sodium Acetate on the Reaction Yield

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Manganese- or Iron-Catalyzed Homocoupling of Grignard Reagents Using Atmospheric Oxygen as an Oxidant

Abstract: Atmospheric oxygen was used for the first time as an oxidant in metal-catalyzed homocoupling of Grignard reagents. These manganese- or iron-catalyzed reactions are efficient, cheap, and eco-friendly. They are applicable to the large-scale synthesis of symmetrical conjugated compounds.

Cited by 243 publications

References 10 publications

Direct Method for Carbon–Carbon Bond Formation: The Functional Group Tolerant Cobalt‐Catalyzed Alkylation of Aryl Halides

Direct Method for Carbon–Carbon Bond Formation: The Functional Group Tolerant Cobalt‐Catalyzed Alkylation of Aryl Halides

Cobalt‐Catalyzed Formation of Symmetrical Biaryls and Its Mechanism

Gold Chloride (AuCl&lt;sub&gt;3&lt;/sub&gt;) Catalyzed Expeditious Homocoupling of Terminal Alkynes at Ambient and Solvent Free Conditions: Impact of Sodium Acetate on the Reaction Yield

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Gold Chloride (AuCl<sub>3</sub>) Catalyzed Expeditious Homocoupling of Terminal Alkynes at Ambient and Solvent Free Conditions: Impact of Sodium Acetate on the Reaction Yield