Strategies to Control Hypervalent Iodine – Primary Amine Reactions

Abstract

The field of hypervalent iodine chemistry has been prevalent since 1886. Its journey from obscurity to coming into the limelight has witnessed many effective transformations which have benefited the synthetic community at large. The reactivity of primary amines with hypervalent iodine reagents causes difficulty in synthetic outcome or not feasible due to high exothermicity of amine iodine which is an acid base reaction. This minireview highlights the worthwhile reactivity of hypervalent iodine reagents with aromatic and aliphatic primary amines. Some recent literature has been discussed to make a clear understanding on how such high reactivity of primary amine is controlled by introducing modulation in either substrate or reaction conditions, most of which are carried out under ambient reaction conditions.

TEMPO‐Mediated Selective Synthesis of Isoxazolines, 5‐Hydroxy‐2‐isoxazolines, and Isoxazoles via Aliphatic δ‐C(sp3)‐H Bond Oxidation of Oximes

“…This reacts with TEMPO‐H to form intermediate ( IV ). Then, the intermediate ( IV ) may react with PhI(OAc) 2 to give intermediate ( V ) that takes part in an elimination reaction and forms intermediate ( VI ), which, after an intramolecular cyclization reaction, provides the final product 4 [20] …”

Iodine-based reagents in photoredox-organocatalysis

“…73 Phenyl iodine diacetate (PIDA) or diacetoxyiodobenzene is one of the important hypervalent iodine reagents used as oxidizing reagent as well as a radical generator for various organic transformations. 20 In 2009, Yadav and coworkers reported the activation of PIDA under visible light irradiation using Eosin Y as organophotocatalyst. With this activation reaction, they were successful in converting aryl boronic acids 28 to the corresponding phenols 29.…”

“…In recent times, several groups have studied some of these aspects, which have added potential value in developing organic chromophores as a sensitizer in visible light-mediated redox chemistry. [11][12][13][14][15] The research area on hypervalent iodine chemistry [16][17][18][19][20][21] has been popular for a long time in synthetic organic chemistry. 22 The iodine-based reagents are environmentally friendly and also have oxidizing ability.…”

“…[26][27][28][29] Easy accessibility, high stability, selective oxidizing ability, non-toxic nature of iodine-based reagents make them workable comfortably in the organic synthesis. [20][21] Recently, the utilization of hypervalent iodine reagents as organo-photocatalyst is gaining popularity. [30][31][32][33] Still, this research field requires substantial development, however, limited reports are available towards the use of hypervalent iodine reagents (HIRs) 22,[34][35][36][37][38] as photocatalyst.…”

A Click Reaction Enabled by Phosphorus‐Oxygen Bond for Synthesis of Triazoles

“…can be used as potential toolbox in organic synthesis. [14] The triazole unit is an essential heterocyclic constituent and has known to have diverse applications in the pharmaceutical and agrochemical industry exhibiting biological activity. [15] Its inbuilt structure infuses high aromatic stability, dipole-dipole and π-π stacking interactions, hydrogen bonding ability which necessitates its demand in biomedical research and supramolecular chemistry.…”