60230-72-0Relevant academic research and scientific papers
Application of Photoclick Chemistry for the Synthesis of Pyrazoles via 1,3-Dipolar Cycloaddition between Alkynes and Nitrilimines Generated In Situ
Remy, Richard,Bochet, Christian G.
, p. 316 - 328 (2018/01/27)
The photochemical extrusion of gaseous nitrogen from 2,5-disubstituted tetrazoles to generate reactive nitrilimines in situ represents an efficient and attractive way to form dipoles that can be used to provide useful chemicals via 1,3-dipolar cycloadditions. The concept of “photoclick chemistry” already inspired numerous researchers, who exploited photochemical processes involving alkenes for the synthesis of adducts or the functionalization of biocompatible materials. The approach requires bioorthogonality, ease of access to the starting materials and operational simplicity. We report herein our investigations toward a photoclick reaction involving 2,5-disubstituted tetrazoles and alkynes as the dipolarophile for the synthesis of pyrazole derivatives. In addition to the numerous reports recently published on the synthesis of pyrazoles, we wish to add to the list a photochemical procedure that represents a mild and atom-economical alternative. Moreover, considering that such nitrilimines precursors can be accessed in one step from inexpensive and abundant starting materials and given the commercial availability of a broad spectrum of alkynes, we examined the scope of the photoclick reaction with respect to reactive partners, enabling the synthesis of a library of useful heteroaromatics.
Copper(I)-catalyzed tandem cyclization/condensation reaction to novel 4,5-dihydropyrazolo[1,5-a]quinolines and pyrazolo[1,5-a]indoles
Hang, Chenchen,Li, Qiulian,Zhu, Yongming,Katayama, Hajime
, p. 3318 - 3324 (2011/09/15)
A facile copper(I)-catalyzed tandem reaction for the synthesis of 4,5-dihydropyrazolo[1,5-a]quinolines and pyrazolo[1,5-a]indoles is reported here. High efficiency and good yields are displayed in this transformation under mild reaction conditions.
Synthesis of pyrazolo[1,5-a]indoles via copper(I)-catalyzed intramolecular amination
Zhu, Yong-Ming,Qin, Lie-Na,Liu, Rui,Ji, Shun-Jun,Katayama, Hajime
, p. 6262 - 6266 (2008/02/10)
A variety of pyrazolo[1,5-a]indole derivatives were synthesized via Cu(I)-catalyzed intramolecular amination reactions. This novel method provides a general and efficient synthesis to indoles fused with pyrazole rings in high yields.
Intramolecular Reaction of the Hydrazonyl Group with Formyl and Oxo Groups: Preparation of Pyrazoloindoles and Related Pyrazolo Compounds
Shen, Jing-Kang,Katayama, Hajime,Takatsu, Noriyuki,Shiro, Itsuo
, p. 2087 - 2098 (2007/10/02)
Lewis acid-catalysed intramolecular nucleophilic attack of a hydrazonyl group onto aldehyde and ketone groups gives pyrazoles and dihydropyrazoles.Pyrazoloindoles and related pyrazolo compounds have also been prepared.
Preparation of Pyrazole and Pyrazoline Derivatives by Intramolecular Reaction of Hydrazones
Shen, Jing-Kang,Katayama, Hajime
, p. 451 - 452 (2007/10/02)
Pyrazole and pyrazoline derivatives are prepared by the intramolecular cyclization reaction of a hydrazonyl group with formyl or keto groups in the presence of a Lewis acid.
Synthesis and pregnancy terminating activity of pyrazolo[1,5-a]indoles and quinolines
Winters,Odasso,Conti,et al.
, p. 215 - 218 (2007/10/02)
In order to clarify the structural requirements for antifertility activity, series of 2-arylpyrazolo[1,5-a]indoles and 2-arylpyrazolo[1,5-a]-quinolines were prepared and tested in rats and hamsters. Their potencies were compared with those of the isomeric
2-Phenyl-pyrazolo-[1,5-a]quinoline compounds
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, (2008/06/13)
New heterocyclic compounds represented by the following formula: STR1 wherein: R and R1 are independently selected from hydrogen, hydroxy, (C1-4)alkyl, (C1-4)alkoxy, (C3-5)alkenyloxy, (C3-5)alkynyloxy
