16860-69-8Relevant academic research and scientific papers
3,4-Dihydro-2H-pyran promoted aerobic oxidative aromatization of 1,3,5-trisubstituted pyrazolines and Hantzsch 1,4-dihydropyridines
Banerjee, Dipanwita,Kayal, Utpal,Karmakar, Rajiv,Maiti, Gourhari
, p. 5333 - 5337 (2014)
An unprecedented facile oxidation of 1,3,5-trisubstituted pyrazolines and Hantzsch 1,4-dihydropyridines (DHPs) to the corresponding pyrazoles and pyridines was observed, mediated by 3,4-dihydro-2H-pyran in air. The reaction showed excellent reactivity, functional group tolerance, and high yield without using any metal and/or halogen based oxidizing agents.
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.
Oxidative aromatization of 1,4-dihydropyridines and pyrazolines using HbA-H2O2: An efficient biomimetic catalyst system providing metabolites of drug candidates
Kumar, Atul,Maurya, Ram Awatar,Sharma, Siddharth
scheme or table, p. 4432 - 4436 (2010/04/05)
Human hemoglobin (HbA) efficiently catalyses the oxidative aromatization of 1,4-dihydropyridines (1,4-DHPs) and pyrazolines with hydrogen peroxide in phosphate buffer. The results of the study reveal that the rates of oxidative aromatization of 1,4-DHPs a
