Hypervalent‐Iodine(III)‐Mediated Oxidative Methodology for the Synthesis of Fused Triazoles

Abstract

The organic chemistry of hypervalent organoiodine compounds has been an area of unprecedented development. This surge in interest in the use of hypervalent iodine compounds has mainly been owing to their highly selective oxidizing properties, environmentally benign character and commercial availability. Hypervalent iodine reagents have also been used as an alternative to toxic heavy metals, owing to their low toxicity and ease of handling. Hypervalent organoiodine(III) reagents are versatile oxidants that have been successfully employed to extend the scope of selective oxidative transformations of complex organic molecules in synthetic chemistry. This Focus Review concerns the tandem in situ generation and 1,5-electrocyclization of N-heteroaryl nitrilimines into fused triazoles. We describe the importance of recently developed hypervalent-organoiodine(III)-catalyzed oxidative cyclization reactions, building towards the conclusion that hypervalent iodine chemistry is a promising frontier for oxidative cyclization, in particular of hydrazones, for the synthesis of fused triazoles.

Chloramine‐T Mediated Facile One Pot Synthesis of Pyrazolyltriazolobenzothiazole Hybrids as Potent Anti‐Infective Agents

“…The hypervalent iodine (III) reagent i. e., iodobenzenediacetate is predominant reagent to synthesize fused 1,2,4‐triazoles by oxidative cyclization of N ‐heteroaryl‐substituted hydrazones …”

Hypervalent Iodine Reagents by Anodic Oxidation: A Powerful Green Synthesis

“…Hypervalent iodine reagents are widely used in modern organic synthesis. [1][2][3][4] These reagents have tremendous synthetic applications,i ncluding difunctionalization of olefins and cyclopropanes, [5][6][7] oxidative couplings, [8][9][10] phenol dearomatizations, [11,12] oxidative formation of heterocycles, [13][14][15][16] aminations, [17,18] halogenations, [19][20][21] arylations, [22][23][24] and rearrangements. [25][26][27][28] In addition, aw ider ange of stereoselective transformationsw as achieved with high degree of stereocontrol using chiral hypervalent iodine reagents and catalytic systems of chiral iodoarenes and terminal oxidants.…”

Design, Synthesis, and Screening of Triazolopyrimidine–Pyrazole Hybrids as Potent Apoptotic Inducers

“…In the literature, 1,2,4‐triazolopyrimidine derivatives are being synthesized by using various synthetic strategies based on oxidation of heterocyclic hydrazones or hydrazides. Out of various oxidative reagents, organoiodine(III) compounds are important reagents for oxidative cyclizations of hydrazones, imines etc., resulting in the formation of various heterocyclic compounds including 1,2,4‐triazolopyrimidines. This surging interest in the use of organoiodine(III) reagents is also due to their lower toxicity than heavy metals and ease of handling that can overcome the toxic properties associated with other oxidizing agents such as POCl 3 , lead tetra‐acetate, bromine etc.…”

“…As the triazolopyrimidine ring is a privileged scaffold in medicinal chemistry, pursuing our interest in improving both structural diversity and pro‐apoptotic potential, we started to explore the chemical space around the triazolopyrimidine nucleus by introducing pyrazolyl moiety using environment friendly organoiodine(III) mediated oxidative approach . Since, oxidative stress and reactive oxygen species play a pivotal role in signal transduction pathway of apoptosis mediated cytotoxicity, thus, in the present study, we also investigate the cytotoxicity and genotoxicity induced by newly synthesized compounds and associated testicular germ cell apoptosis within caprines at cellular and molecular level.…”