A Straightforward Synthesis of Pyrazolines and Pyrazoles: Palladium‐Catalyzed Carbonylative Vinylation–Cyclocondensation Reactions of Aryl Halides

Wu, Xiao‐Feng; Neumann, Helfried; Beller, Matthias

doi:10.1002/ejoc.201100654

Cited by 18 publications

(13 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Method C: Reaction of hydrazines with arylhalides, carbon monoxide and styrenes Wu et al reported an efficient methodology for two-step onepot synthesis of 2-pyrazolines in overall yields of 38-78 %. [52] The first step was based on synthesis of chalconic intermediates. This was performed by vinylative carbonylation of structurally diverse aryl iodides 40 a using carbon monoxide 40 b and various styrenes 40 c in the presence of [(cinnamyl) PdCl] 2 , ligand 40 f/40 g, and triethylamine under reflux condition in dioxane or DMF.…”

Section: Methods B: Reaction Of Hydrazines With Halogenated π Systems and Propargyl Alcoholsmentioning

confidence: 99%

Synthesis of 2‐Pyrazolines from Hydrazines: Mechanisms Explained

et al. 2021

View full text Add to dashboard Cite

2-Pyrazoline core is a very interesting five-membered heterocycle, which has been explored in recent years due to its vast applications as the core structure of bioactive and industrial agents. Based on literature studies, versatile synthetic approaches have been employed for the preparation of 2pyrazolines, among them the reaction between hydrazines and α,β-unsaturated enones as the most used method. In this review article, different methods for the synthesis of 2-pyrazolines using hydrazine derivatives were classified and presented.Initially, numerous catalytic methods for the preparation of 2pyrazolines from hydrazines and α,β-unsaturated enones are reviewed and various aspects of these methods discussed including catalyst efficiency, catalyst recovery, green chemistry, cost-effectiveness, scope of the method, enantioselectivity, and yield. In addition, reactions between hydrazines and other reagents in multicomponent and two-component reactions, developed recently, are discussed. Finally, some of the important applications of 2-pyrazolines are summarized.

show abstract

Section: Methods B: Reaction Of Hydrazines With Halogenated π Systems and Propargyl Alcoholsmentioning

confidence: 99%

Synthesis of 2‐Pyrazolines from Hydrazines: Mechanisms Explained

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Moreover, the same catalytic system was applied in the straightforward synthesis of pyrazolines and pyrazoles in 38-79% isolated yields. 65 Later, the same research group also proved that the catalyst derived from palladium(II) bromide and ligand 8 was suitable for Hecktype carbonylative reactions of aryl bromides and vinyl ethers. 66 Under carbon monoxide (5 bar) and nitrogen (75 bar), various 1-aryl-3-alkoxyprop-2-en-1-ones were obtained in 30-75% yields, and the protocol tolerated other styrenes well.…”

Section: Figure 2 Selected Heterocyclic Mono[dialkyl(biaryl)phosphine]smentioning

confidence: 97%

Design and Development of Ligands for Palladium-Catalyzed Carbonylation Reactions

et al. 2014

View full text Add to dashboard Cite

The palladium-catalyzed carbonylation reaction remains a challenging and significant research field in organic chemistry, and has emerged as a powerful and straightforward protocol for the preparation of various bioactive carbonyl compounds under quite mild reaction conditions. The achievements in this area are correlated to the design and development of versatile ligands that not only facilitate the catalytic transformation, but also provide additional control over the selectivity of the reactions. In this context, a variety of rationally designed ligands with different electronic and steric properties have been synthesized and applied in palladium-catalyzed carbonylation reactions in recent decades. This review focuses mainly on the strategy of ligand design and the results obtained with representative ligands that have different σ-donor properties in the intra-and intermolecular palladium-catalyzed carbonylation reactions of (pseudo)haloarenes with gaseous carbon monoxide and numerous types of nucleophiles. The current limitations and potential trends for further development of palladium-catalyzed carbonylation reactions are also highlighted.

show abstract

“…The reaction involves the palladium-catalysed carbonylative vinylation of aryl halides to give the corresponding chalcones (Scheme 31a) [313], which undergo in situ cyclocondensation with hydrazines to afford 2-pyrazolines (Scheme 31b). Further oxidation with DDQ at room temperature for 2 hours provided pyrazoles in moderate overall yields for the three-step sequence [314]. The synthesis of 2-pyrazolines by the reaction of chalcones with hydrazines generally occurs in good yields.…”

Section: Transformation Of Chalcones To Pyrazolesmentioning

confidence: 99%

Chalcones as Versatile Synthons for the Synthesis of 5- and 6-membered Nitrogen Heterocycles

Albuquerque¹,

Santos²,

Cavaleiro³

et al. 2014

COC

View full text Add to dashboard Cite

Chalcones belong to the flavonoid family which constitutes one of the major classes of naturally occurring oxygen heterocyclic compounds. The ,-unsaturated carbonyl system of chalcones possesses two electrophilic reactive centers allowing them to participate in addition reactions via attack to the carbonyl group (1,2-addition) or involving the-carbon (1,4-conjugate addition), leading to the synthesis of promising bioactive heterocyclic compounds. The purpose of this review is to present a systematic survey of the most recent literature that uses chalcones in the synthesis of biologically active 5-and 6-membered nitrogen heterocycles such as pyrroles, indoles, isoxazoles, imidazoles, pyrazoles, indazoles, triazoles, tetrazoles, pyridines and pyrimidines. Efficiency, easy-to-handle and cheap reagents, alternative heating conditions and greener protocols will be highlighted. In this review we will cover the literature since the beginning of the 21 st century in more than 400 publications.

show abstract

A Straightforward Synthesis of Pyrazolines and Pyrazoles: Palladium‐Catalyzed Carbonylative Vinylation–Cyclocondensation Reactions of Aryl Halides

Cited by 18 publications

References 53 publications

Synthesis of 2‐Pyrazolines from Hydrazines: Mechanisms Explained

Synthesis of 2‐Pyrazolines from Hydrazines: Mechanisms Explained

Design and Development of Ligands for Palladium-Catalyzed Carbonylation Reactions

Chalcones as Versatile Synthons for the Synthesis of 5- and 6-membered Nitrogen Heterocycles

Contact Info

Product

Resources

About