CO<sub>2</sub>‐Promoted C=N Bond Cleavage of Amidines Leading to Multi‐Substituted Pyridines

Liu, Jianming; Yan, Xuyang; Yue, Yuanyuan; Zhao, Shufang; Zhang, Jia; Sun, Yangyang; Zhuo, Kelei

doi:10.1002/adsc.201800401

Cited by 5 publications

(1 citation statement)

References 98 publications

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“…Recently the number of reports about the applications of nucleophilic behavior of DBU has increased tremendously . [11] As such an increasing number of reports in the literature that are more amenable to the in‐situ ring‐opening reaction of DBU with acetylenic esters, [12] 1, 4‐diaryl‐1, 3‐diynes, [13] aldehydes [14] and phenylboronic acids [15] forming N‐functionalised products have appeared. The extension of Chan‐Lam coupling was reported by our research group with DBU/DBN/TBD as reaction partners [15] .…”

Section: Methodsmentioning

confidence: 99%

Ullmann Coupling Reaction of Bicyclic Amidines DBU/DBN with Aryl Halides: A Pathway to the Synthesis of ϵ‐Caprolactam Derivatives

et al. 2021

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This paper demonstrates a selective, mild approach to Ullmann amination of aryl halides to synthesizeN‐alkylated derivatives of ϵ‐caprolactam. The synthetic route involves anin‐situring‐opening of 1,8‐diazabicyclo[5.4.0]undec‐8‐ene (DBU) followed by concurrent arylation with aryl halides in the presence of copper iodide as a catalyst under ligand‐free conditions. This method provides a new entry to a wide variety of ϵ‐caprolactam derivatives in good to excellent yields in a single synthetic sequence. Similarly, other bicyclic amidines such as 1, 5‐diazabicyclo‐[4.3.0]non‐5‐ene (DBN), and 1,5,7 triazabicyclo[4.4.0] dec‐5‐ene (TBD) also showed good to very high reactivity.Azepan‐2‐one, or Caprolactam, is an important synthon in polymer chemistry and has a global demand as it is employed to make Nylon 6 filament, fiber, and plastics.[1]The global caprolactam market size is expected to expand for the growing textile industry with rising demand for plastics in the construction of automotive, electrical, and electronic sectors. Additionally, technological advancements aimed at improving the cost‐effective manufacturing process of caprolactam, to minimize the release of hazardous waste into the environment is of vital necessity. Derivatives of ϵ‐caprolactam are of interest for the production of modified nylons[2]and nanogels.[3]Several Azepinones and their analogs play an important role in medicinal chemistry,[4]used in the synthesis of pharmaceutical drugs including Benazepril,[5]Telcagepant,[6]and Ivabradine.[7]

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Section: Methodsmentioning

confidence: 99%

Ullmann Coupling Reaction of Bicyclic Amidines DBU/DBN with Aryl Halides: A Pathway to the Synthesis of ϵ‐Caprolactam Derivatives

et al. 2021

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γ‐Functionalization of α,β‐Unsaturated Nitriles under Mild Conditions: Versatile Synthesis of 4‐Aryl‐2‐Bromopyridines

Sim

Rhee

et al. 2019

Adv Synth Catal

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This report describes the synthesis of 4‐aryl‐2‐halopyridines via γ‐functionalization of α,β‐unsaturated nitriles, which were obtained by the HWE reaction with the corresponding ketones. The key features of our methods involve a conjugated γ‐enamine formation of α,β‐unsaturated nitrile (enamino nitrile), followed by consecutive intramolecular cyclization, resulting in heteroaromatic compounds like 2‐halopyridines, α‐pyrone, etc.magnified image

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Synthesis of Poly‐Substituted Pyridines via Noble‐Metal‐Free Cycloaddition of Ketones and Imines

Mao

Hong

et al. 2021

Chemistry An Asian Journal

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An eco-friendly and noble-metal-free formal [4 + 2] cycloaddition reaction was developed for the efficient synthesis of biologically interesting poly-substituted pyridines from easily available ketones and imines, whereby two sequential CÀ C bonds are formed. The given approach features a unique synthetic strategy of imines and ketones with wide substrate scope, good functional group tolerance, mild conditions and operational simplicity, which represents a more direct pathway to synthesize polysubstituted pyridines than traditional methods.

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CO₂‐Promoted C=N Bond Cleavage of Amidines Leading to Multi‐Substituted Pyridines

Cited by 5 publications

References 98 publications

Ullmann Coupling Reaction of Bicyclic Amidines DBU/DBN with Aryl Halides: A Pathway to the Synthesis of ϵ‐Caprolactam Derivatives

Ullmann Coupling Reaction of Bicyclic Amidines DBU/DBN with Aryl Halides: A Pathway to the Synthesis of ϵ‐Caprolactam Derivatives

γ‐Functionalization of α,β‐Unsaturated Nitriles under Mild Conditions: Versatile Synthesis of 4‐Aryl‐2‐Bromopyridines

Synthesis of Poly‐Substituted Pyridines via Noble‐Metal‐Free Cycloaddition of Ketones and Imines

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CO2‐Promoted C=N Bond Cleavage of Amidines Leading to Multi‐Substituted Pyridines

Cited by 5 publications

References 98 publications

Ullmann Coupling Reaction of Bicyclic Amidines DBU/DBN with Aryl Halides: A Pathway to the Synthesis of ϵ‐Caprolactam Derivatives

Ullmann Coupling Reaction of Bicyclic Amidines DBU/DBN with Aryl Halides: A Pathway to the Synthesis of ϵ‐Caprolactam Derivatives

γ‐Functionalization of α,β‐Unsaturated Nitriles under Mild Conditions: Versatile Synthesis of 4‐Aryl‐2‐Bromopyridines

Synthesis of Poly‐Substituted Pyridines via Noble‐Metal‐Free Cycloaddition of Ketones and Imines

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CO₂‐Promoted C=N Bond Cleavage of Amidines Leading to Multi‐Substituted Pyridines