gem‐Difluoroallylation of Aryl Halides and Pseudo Halides with Difluoroallylboron Reagents in High Regioselectivity

AbstractElectrochemical catalytic reductive cross couplings are powerful and sustainable methods to construct C−C bonds by using electron as the clean reductant. However, activated substrates are used in most cases. Herein, we report a general and practical electro-reductive Ni-catalytic system, realizing the electrocatalytic carboxylation of unactivated aryl chlorides and alkyl bromides with CO2. A variety of unactivated aryl bromides, iodides and sulfonates can also undergo such a reaction smoothly. Notably, we also realize the catalytic electrochemical carboxylation of aryl (pseudo)halides with CO2 avoiding the use of sacrificial electrodes. Moreover, this sustainable and economic strategy with electron as the clean reductant features mild conditions, inexpensive catalyst, safe and cheap electrodes, good functional group tolerance and broad substrate scope. Mechanistic investigations indicate that the reaction might proceed via oxidative addition of aryl halides to Ni(0) complex, the reduction of aryl-Ni(II) adduct to the Ni(I) species and following carboxylation with CO2.

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Recent Progress in Metal Catalyzed Direct Carboxylation of Aryl Halides and Pseudo Halides Employing CO2: Opportunities for11C Radiochemistry

ChemCatChem ◽

10.1002/cctc.201600943 ◽

2016 ◽

Vol 8 (24) ◽

pp. 3692-3700 ◽

Cited By ~ 15

Author(s):

Muneer Ahamed ◽

Joost Verbeek ◽

Uta Funke ◽

Joan Lecina ◽

Alfons Verbruggen ◽

...

Keyword(s):

Recent Progress ◽

Aryl Halides ◽

Pseudo Halides ◽

Metal Catalyzed

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Mild Temperature Copper-Catalyzed Amination of Aryl Halides with Aqueous Ammonia in the Presence of Pyridyldiketone Ligands

10.26434/chemrxiv.7756886.v1 ◽

2019 ◽

Author(s):

Racha Abed Ali Abdine ◽

Anna Walczak ◽

Sultan Abu A Aeash ◽

Gracjan Kurpik ◽

Artur R. Stefankiewicz ◽

...

Keyword(s):

Catalytic System ◽

Aqueous Ammonia ◽

Aryl Halides ◽

Efficient Coupling ◽

Ambidentate Ligand ◽

Mild Temperature

Ambidentate ligand pyridyldiketones were used in combination with copper to catalyze maintain of aryl halides under very mild temperatures. This novel catalytic system allow efficient coupling in one of the smoothest conditions ever reported in literature.

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Carbon-Heteroatom Cross-Coupling via an Electronically Excited Nickel (II) Complex

10.26434/chemrxiv.9736049.v1 ◽

2019 ◽

Author(s):

Randolph Escobar ◽

Jeffrey Johannes

Keyword(s):

Energy Transfer ◽

Functional Groups ◽

Cross Coupling ◽

Reductive Elimination ◽

Aryl Halides ◽

Coupling Reactions ◽

General Methodology ◽

Cross Coupling Reactions ◽

Electronically Excited ◽

Energy Transfer Pathway

<div>While carbon-heteroatom cross coupling reactions have been extensively studied, many methods are specific and</div><div>limited to a set of substrates or functional groups. Reported here is a method that allows for C-O, C-N and C-S cross coupling reactions under one general methodology. We propose that an energy transfer pathway, in which an iridium photosensitizer produces an excited nickel (II) complex, is responsible for the key reductive elimination step that couples aryl halides to 1° and 2° alcohols, anilines, thiophenols, carbamates and sulfonamides.</div>

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Chiral Mn(III) Salen Complex Immobilized on CuFe2O4@SiO2-NH2 NPs: A Cheap and Efficient Catalyst for N-arylation of Aryl Halides and Phenylboronic Acid Under Mild Conditions

Letters in Organic Chemistry ◽

10.2174/1570178616666190919110639 ◽

2020 ◽

Vol 17 (11) ◽

pp. 857-863

Author(s):

Mohammad Ali Nasseri ◽

Seyyedeh Ameneh Alavi ◽

Milad Kazemnejadi ◽

Ali Allahresani

Keyword(s):

Phenylboronic Acid ◽

Significant Loss ◽

Aryl Halides ◽

Coupling Reactions ◽

Efficient Catalyst ◽

Aryl Chlorides ◽

Mild Conditions ◽

Cross Coupling Reactions ◽

Salen Complex ◽

Ft Ir

A convenient and efficient chiral CuFe2O4@SiO2-Mn(III) Ch.salen nanocatalyst has been developed for the C-N cross-coupling reactions of aryl halides/ phenylboronic acid with N-heterocyclic compounds in water and/or DMSO under mild conditions. The catalyst could be applied for the N-arylation of a variety of nitrogen-containing heterocycles with aryl chlorides, bromides, iodides and phenylboronic acid under mild conditions. Moderate to good yields were achieved for all substrates. The structure of catalyst was characterized using various techniques including FT-IR, FE-SEM, EDX, XRD, TEM and TGA. The catalyst can be simply recovered and reused for several times without significant loss of activity.

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Piperazine as an Inexpensive and Efficient Ligand for Pd-Catalyzed Homocoupling Reactions to Synthesize Bipyridines and Their Analogues

Current Organic Synthesis ◽

10.2174/1570179415666180913131905 ◽

2019 ◽

Vol 16 (1) ◽

pp. 173-180

Author(s):

Mingwei Chen ◽

Jinyu Hu ◽

Xiaoli Tang ◽

Qiming Zhu

Keyword(s):

Transition Metal ◽

Oxidation State ◽

Coupling Reaction ◽

Aryl Halides ◽

Metal Species ◽

Good Substrate ◽

Active Metal ◽

Homocoupling Reaction ◽

Catalytic Cycles ◽

Reductive Homocoupling

Aim and Objective: The synthesis of bipyridines, especially 2, 2’-bipyridines, remains challenging because the catalytic cycle can be inhibited due to coordination of bipyridine to transition metal. Thus, the development of efficient methods for the synthesis of bipyridines is highly desirable. In the present work, we presented a promising approach for preparation of bipyridines via a Pd-catalyzed reductive homocoupling reaction with simple piperazine as a ligand. Materials and Methods: Simple and inexpensive piperazine was used as a ligand for Pd-catalyzed homocoupling reaction. The combination of Pd(OAc)2 and piperazine in dimethylformamide (DMF) was observed to form an excellent catalyst and efficiently catalyzed the homocoupling of azaarenyl halides, in which DMF was used as the solvent without excess reductants although stoichiometric reductant was generally required to generate the low-oxidation-state active metal species in the catalytic cycles. </P><P> Results: In this case, good to excellent yields of bipyridines and their (hetero) aromatic analogues were obtained in the presence of 2.5 mol% of Pd(OAc)2 and 5 mol% of piperazine, using K3PO4 as a base in DMF at 140°C. Conclusion: According to the results, piperazine as an inexpensive and efficient ligand was used in the Pd(OAc)2-catalyzed homocoupling reaction of heteroaryl and aryl halides. The coupling reaction was operationally simple and displayed good substrate compatibility.

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