Cyclization of o-phenylenediamines by CO<sub>2</sub>in the presence of H<sub>2</sub>for the synthesis of benzimidazoles

Yu, Bo; Zhang, Hongye; Zhao, Yanfei; Chen, Sha; Xu, Jilei; Huang, Changliang; Liu, Zhimin

doi:10.1039/c2gc36517k

Cited by 94 publications

(57 citation statements)

References 32 publications

(2 reference statements)

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“…Although silanes are well reported and active reducing agents for these types of reactions, they are low atom‐economical and require an expensive catalyst . In the case of silane, most of the reaction systems are non‐recyclable and expensive compared with borane . In the case of heterogeneous catalysts, the use of silane as reducing agents is problematic owing to the generation of solid waste, which is not soluble in water and common solvents.…”

Section: Resultsmentioning

confidence: 99%

Ru@PsIL‐Catalyzed Synthesis of N‐Formamides and Benzimidazole by using Carbon Dioxide and Dimethylamine Borane

2018

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This work reports the synthesis and characterization of ruthenium nanoparticles (Ru NPs) supported on polymeric ionic liquids (PILs). This catalyst shows high catalytic activity towards the N‐formylation of amines and synthesis of benzimidazoles from 1,2‐diamines and carbon dioxide (CO2) by reductive dehydrogenation of dimethylamine borane. This methodology shows excellent functional group tolerance with broad substrate scope towards the synthesis of N‐formamides and benzimidazoles. Interestingly, this protocol also provides the tandem reduction of 2‐nitroamines and CO2 to synthesize benzimidazoles. It was proposed that the ionic liquid phase of the polymer plays pivotal roles such as assisting the stabilization of nanoparticles electrostatically, providing an ionic environment, and controlling the easy access of the substrates/reagents to the active sites. The developed methodology utilizes CO2 as a C1 source and water/ethanol as a green solvent system. Additionally, the catalyst was found to be recyclable in nature and shows five consecutive recycling runs without significant loss in its activity.

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Section: Resultsmentioning

confidence: 99%

Ru@PsIL‐Catalyzed Synthesis of N‐Formamides and Benzimidazole by using Carbon Dioxide and Dimethylamine Borane

2018

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“…Amine-CO2 reductive coupling was also performed using hydrosilane (R3Si-H) or hydroborane (R2B-H) as the reductant on metal (Cu, Fe, Ni, and Rh) [189][190][191][192][193] catalysts such as [Ni(μ-H)(dippe)]2 (dippe = 1,2-bis(diisopropylphosphino)ethane) [192] and Cu(iPr-NHC)(O t Bu) (iPrNHC) [193]. More recently, non-carbonyl or fully deoxygenated products, e.g., formamidines (RN = C(H)NR 2 ) and methylamines (R 2 NCH 3 ) were obtained at elevated temperature and pressure (Scheme 21) from o-phenylenediamines with RuCl 2 (dppe) 2 [194], as well as from primary and secondary amines with Ru(acac) 3 /triphos [195] or Ru(triphos)(tmm) [187], [Ru II (dmso) 4 Cl 2 ]/P( n Bu)(Ad) 2 [196], and Zn(iPrNHC)Cl [196] using H 2 and PhSiH 3 as reductants. Recently, reductive coupling of CO 2 with amines and o-phenylenediamines was achieved using organo-base (TBD) [197,198], iPrNHC [199,200], and proazaphosphatrane (VB Me ) [201] to produce formamides [196,199], formamidines [200], tertiary methylamines, and methylene diamines [198,201] using hydrosilane (PhSiH 3 ) or hydroborane (9-BBN) as reductants (Scheme 22).…”

Section: Diagonal (Reductive) Co 2 Functionalizationmentioning

confidence: 99%

“…More recently, non-carbonyl or fully deoxygenated products, e.g., formamidines (RN = C(H)NR′2) and methylamines (R2NCH3) were obtained at elevated temperature and pressure (Scheme 21) from o-phenylenediamines with RuCl2(dppe)2 [194], as well as from primary and secondary amines with Ru(acac)3/triphos [195] or Ru(triphos)(tmm) [187], [Ru II (dmso)4Cl2]/P( n Bu)(Ad)2 [196], and Zn(iPrNHC)Cl [196] using H2 and PhSiH3 as reductants. Recently, reductive coupling of CO2 with amines and o-phenylenediamines was achieved using organo-base (TBD) [197,198], iPrNHC [199,200], and proazaphosphatrane (VB Me ) [201] to produce formamides [196,199], formamidines [200], tertiary methylamines, and methylene diamines [198,201] Scheme 20.…”

Section: Diagonal (Reductive) Co 2 Functionalizationmentioning

confidence: 99%

Molecular Catalysis for Utilizing CO2 in Fuel Electro-Generation and in Chemical Feedstock

Leung¹,

Ho²

2019

Catalysts

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Processes for the conversion of CO2 to valuable chemicals are highly desired as a result of the increasing CO2 levels in the atmosphere and the subsequent elevating global temperature. However, CO2 is thermodynamically and kinetically inert to transformation and, therefore, many efforts were made in the last few decades. Reformation/hydrogenation of CO2 is widely used as a means to access valuable products such as acetic acids, CH4, CH3OH, and CO. The electrochemical reduction of CO2 using hetero- and homogeneous catalysts recently attracted much attention. In particular, molecular CO2 reduction catalysts were widely studied using transition-metal complexes modified with various ligands to understand the relationship between various catalytic properties and the coordination spheres above the metal centers. Concurrently, the coupling of CO2 with various electrophiles under homogeneous conditions is also considered an important approach for recycling CO2 as a renewable C-1 substrate in the chemical industry. This review summarizes some recent advances in the conversion of CO2 into valuable chemicals with particular focus on the metal-catalyzed reductive conversion and functionalization of CO2.

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“…2013 beschrieben Liu und Mitarbeiter eine Methode, die unter Verwendung eines CO 2 /H 2 ‐Gemischs in Gegenwart eines Rutheniumkomplexes Benzimidazole aus o ‐Phenyldiaminen in hohen Ausbeuten lieferte (Schema ) . Diese Umsetzung ergänzt das Protokoll von Cantat aus demselben Jahr, das aber auf der Verwendung von Silanen basiert (siehe Schema ) …”

Section: Katalytische Reduktive N‐alkylierung Von Aminen Mit Molekulaunclassified

Katalytische reduktive N‐Alkylierungen unter Verwendung von CO₂ und Carbonsäurederivaten: Aktuelle Entwicklungen

2019

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N‐Alkylamine sind Schlüsselintermediate in der Synthese von Feinchemikalien, Farb‐ und Naturstoffen und deshalb wertvolle Bausteine in der organischen Chemie. Entsprechend ist die Entwicklung nachhaltiger und effizienter Protokolle für die Synthese von N‐Alkylaminen von großem Interesse in der Industrie und Forschung. Bislang wird die Aminsynthese überwiegend über reduktive Protokolle bewerkstelligt, z. B. durch reduktive Aminierung oder durch N‐Alkylierung durch Wasserstoff‐Autotransfer unter Verwendung von Carbonylverbindungen oder Alkoholen als Alkylierungsreagenzien. In den letzten Jahren wurden zudem Carbon‐/Kohlensäurederivate und CO2 als alternative Alkylierungsmittel eingeführt. Die sichere Verwendung, der einfache Zugang und die gute Stabilität dieser Reagenzien treibt die Entwicklung neuer reduktiver Umwandlungen als nützliche Alternativen zu bestehenden Protokollen voran. In diesem Aufsatz fassen wir die literaturbekannten Beispiele von Eintopfmethoden zur reduktiven Alkylierung unter Verwendung von Carbon‐/Kohlensäurederivaten oder CO2 als Alkylierungsreagenzien zusammen.

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Cyclization of o-phenylenediamines by CO₂in the presence of H₂for the synthesis of benzimidazoles

Cited by 94 publications

References 32 publications

Ru@PsIL‐Catalyzed Synthesis of N‐Formamides and Benzimidazole by using Carbon Dioxide and Dimethylamine Borane

Ru@PsIL‐Catalyzed Synthesis of N‐Formamides and Benzimidazole by using Carbon Dioxide and Dimethylamine Borane

Molecular Catalysis for Utilizing CO2 in Fuel Electro-Generation and in Chemical Feedstock

Katalytische reduktive N‐Alkylierungen unter Verwendung von CO₂ und Carbonsäurederivaten: Aktuelle Entwicklungen

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Cyclization of o-phenylenediamines by CO2in the presence of H2for the synthesis of benzimidazoles

Cited by 94 publications

References 32 publications

Ru@PsIL‐Catalyzed Synthesis of N‐Formamides and Benzimidazole by using Carbon Dioxide and Dimethylamine Borane

Ru@PsIL‐Catalyzed Synthesis of N‐Formamides and Benzimidazole by using Carbon Dioxide and Dimethylamine Borane

Molecular Catalysis for Utilizing CO2 in Fuel Electro-Generation and in Chemical Feedstock

Katalytische reduktive N‐Alkylierungen unter Verwendung von CO2 und Carbonsäurederivaten: Aktuelle Entwicklungen

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Cyclization of o-phenylenediamines by CO₂in the presence of H₂for the synthesis of benzimidazoles

Katalytische reduktive N‐Alkylierungen unter Verwendung von CO₂ und Carbonsäurederivaten: Aktuelle Entwicklungen