61001-36-3Relevant academic research and scientific papers
[Cu(maloNHC)]-catalyzed synthesis of 2-aryl pyrazolo[5,1-a]isoquinolines by annulation of N′-(2-((trimethylsilyl)ethynyl)benzylidene)hydrazides with terminal aromatic alkynes
Liu, Huixin,Lu, Le,Hua, Ruimao
, p. 6428 - 6435 (2017/10/09)
A [Cu(maloNHC)]-catalyzed synthesis of 2-aryl pyrazolo[5,1-a]isoquinolines via annulation of N′-(2-((trimethylsilyl)ethynyl)benzylidene)hydrazides with terminal aromatic alkynes was developed.
Cu-Catalyzed alkynylation-cyclization cascade for the construction of the pyrazolo[5,1-a]isoquinoline skeleton
Yang, Yanfang,Ren, Hailong,Wang, Dongyang,Shi, Feng,Wu, Chunrui
, p. 10434 - 10441 (2013/09/02)
A Cu-catalyzed Sonogashira-type coupling of 3-(2-bromophenyl)pyrazoles with terminal alkynes combined with a subsequent electrophilic cyclization in the same pot was developed to afford pyrazolo[5,1-a]isoquinolines. The transformation proceeds without the necessity of using Pd or ligands, while an Ag additive is beneficial. The Royal Society of Chemistry 2013.
From N-benzoylpyridinium imides to pyrazolo[1,5-a]pyridines: A mechanistic discussion on a stoichiometric Cu protocol
Ling, Lin,Chen, Jingqing,Song, Jiahui,Zhang, Yuhai,Li, Xinqian,Song, Lijuan,Shi, Feng,Li, Yuxue,Wu, Chunrui
supporting information, p. 3894 - 3902 (2014/03/21)
A Cu-mediated preparation of 2-substitiuted pyrazolo[1,5-a]pyridines from N-benzoylpyridinium imides and terminal alkynes is described using stoichiometric Cu(OAc)2 as both the mediator and the oxidant. Extensive DFT calculations suggest a Cu(i
Synthesis of 2- and 2,3-substituted Pyrazolo[1,5- a ]pyridines: Scope and mechanistic considerations of a domino direct alkynylation and cyclization of n -iminopyridinium ylides using alkenyl bromides, alkenyl iodides, and alkynes
Mousseau, James J.,Bull, James A.,Ladd, Carolyn L.,Fortier, Angelique,Sustac Roman, Daniela,Charette, Andre B.
experimental part, p. 8243 - 8261 (2012/01/03)
Direct functionalization and tandem processes have both received considerable recent interest due to their cost and time efficiency. Herein we report the synthesis of difficult to obtain 2-substituted pyrazolo[1,5-a] pyridines through a tandem palladium-catalyzed/silver-mediated elimination/direct functionalization/cyclization reaction involving N-benzoyliminopyridinium ylides. As such, these biologically important molecules are prepared in an efficient, high-yielding manner, only requiring a two-step sequence from pyridine. Aryl-substituted alkenyl bromides and iodides are effective ylide coupling partners. Mechanistic studies led to the use of terminal alkynes, which extended the scope of the reaction to include alkyl substitution on the unsaturated reactive site. The optimization, scope, and mechanistic considerations of the process are discussed.
Synthesis of 2-Substituted Pyrazolo[1,5-a]pyridines through Cascade Direct Alkenylation/Cyclization Reactions
Mousseau, James J.,Fortier, Angelique,Charette, Andre B.
supporting information; experimental part, p. 516 - 519 (2010/05/02)
[Chemical equation presented] The synthesis of 2-substituted pyrazolo[1,5-a]pyridines from N-iminopyridinium ylides is described. These medicinally interesting compounds are formed through a cascade process involving a palladium-catalyzed direct alkenylation reaction followed by silver-mediated cyclization. The reaction can be performed with a wide range of electron-poor and electron-rich alkenyl iodides in good yields. This work represents perhaps the most direct route for the preparation of these compounds.
Thermal Rearrangements of Cyclic Amine Ylides. III. Intramolecular Cyclization of 2-Ethynylpyridine N-Imides to 3-Azaindolizine Derivatives
Tsuchiya, Takashi,Sashida, Haruki,Konoshita, Ari
, p. 4568 - 4572 (2007/10/02)
Treatment of the N-aminopyridinium salts (5a-e) prepared from 2-ethynylpyridines (4) with potassium carbonate resulted in an intramolecular cyclization to give the corresponding 3-azaindolizines (6) (pyrazolopyridines), presumably via the ionic in
Cycloaddition Reactions of N-p-Toluenesulfonylimino Derivatives of Quinoline and Isoquinoline. A Route to Pyrazoloquinolines and Pyrazoloisoquinolines
Sundberg, Richard J.,Ellis, James E.
, p. 573 - 576 (2007/10/02)
N-p-Toluenesulfonylimino ylides of quinoline and isoquinoline give cycloadducts with electrophilic acetylenes at 105 deg C.The adducts are spontaneously aromatized under the conditions of their formation by elimination of p-toluenesulfinic acid to give py
Ring Closures of syn-(E)- and anti-(E)-(2-Quinolylmethyl)- and -(1-Isoquinolylmethyl)ketoximes to Pyrazoloquinolines and Pyrazoloisoquinolines
Gnichtel, Horst,Moeller, Bernd
, p. 1751 - 1759 (2007/10/02)
The (2-quinolylmethyl)- and (1-isoquinolylmethyl)ketoximes 2a-e and 4a-d have been prepared and the oxime configurations determined.The Pyrazoloquinolines 7a, b and the pyrazoloisoquinoline 8a are formed by Beckmann reaction of the anti-isomers 2a, b and 4a, while O-mesitylsulfonylhydroxylamine yields the pyrazolo compounds 7 and 8, independent of the oxime configuration.
