Synthetic strategies for 1,4,5/4,5‐substituted azoles: A perspective review

Abstract

Azole nucleus represents an important class of biologically active compounds that are gaining more attention in the field of medicinal chemistry due to large number of structure diversity. Among azoles, pyrazoles, and isoxazoles fivemembered nitrogen containing heterocyclic compounds are associated wide range of biological activities such as anticancer, antimicrobial, anti-inflammatory, antioxidant, etc. Some of azole derivatives (e.g., 1,4,5-trisubstituted pyrazoles, 4,5-disubstituted isoxazoles, and 4,5-disubstituted-1H-pyrazoles) are still unexplored in literature, these unexplored azoles have fascinated the consideration of many researchers to study their framework synthetically and biologically. This present review is an attempt to update and understand the chemistry of unexplored pyrazoles and isoxazoles along with their medicinal importance. This article would definitely help the researchers to bring further enhancement in the synthesis of biologically active pyrazoles and isoxazoles.

Asymmetric Organocatalytic Mannich Reaction in the Synthesis of Hybrid Isoindolinone-Pyrazole and Isoindolinone-Aminal from Functionalized α-Amidosulfone

“…In order to confirm this hypothesis and overcome the racemization issue, our attention focused on the use of hydrazine, which should react selectively with acetylacetone to provide pyrazole ring, [ 24 ] a moiety also found in a very large number of bioactive compounds, [ 10 , 11 , 12 ] often combined with other heterocycles [ 12 ]. Therefore, the enantioenriched acyclic product 2 was treated with hydrazine under the conditions shown in Scheme 2 , leading nicely to the pyrazole derivative 4 in a very high yield.…”

“…The value of some classes of compounds is often associated with the structural diversity and the presence of different functionalities and moieties. This feature is relevant in classes of heterocycles such as isoindolinones [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ] and pyrazoles [ 10 , 11 , 12 ], whose biological activities are tuned by the linking of additional nitrogen-containing substituents or heterocyclic groups such as piperazines, piperidines, and so on ( Figure 1 ).…”

The anti‐breast cancer potential of indole/isatin hybrids

“…Azoles have excellent physicochemical benefits for creating biologically active compounds and might generate a variety of noncovalent interactions with biological targets. [43,44] Mechanistically, azoles can suppress tumor proliferation, invasion, and metastasis by regulating many signaling pathways, making them attractive scaffolds for the establishment of innovative anti-BC targets. [45,46] Therefore, indole/ isatin-azole hybrids with a sensible design could result in beneficial therapeutic approaches targeting BC.…”

Synthesis, Characteritation, Optoelectronic Properties and DFT Studies of Novel 4,5‐Diarylpyrazole‐1‐Carboxylates

“…In the recent past, several researchers have used α‐benzotriazolyl‐α, β‐unsaturated aldehydes, [21] phenoxy enamino ketones, [22] and sydnones, [23] as starting materials and ketal [24] rearrangement methodologies for the regioselective synthesis of 4,5/1,4,5‐subsituted pyrazoles. Our research group has recently compiled the different methods available for the synthesis of these pyrazoles [25] . Moreover, we have also developed a convenient, direct, metal free and regioselective synthesis for 4,5/1,4,5‐subsituted pyrazoles using geminal ditosyloxy ketones as precursor [26] .…”