It is difficult to imagine organic chemistry without organo-halogen compounds and the molecular halogens needed for their preparation. The halogens have very different reactivity, with iodine usually requiring some form of activation, while others are reactive and hazardous chemicals. To avoid their use, various modified reagents have been discovered (N-bromo- and N-chlorosuccinimide, Selectfluor..), but halogens are used to prepare these reagents and when they are used the atom economy is poor. A better approach, which is based on biomimetric research on oxidative halogenation in nature, consists of generating the halogenating reagent in situ under acidic conditions from a halide salt. The result of such a reaction has been halogenation with 100 % halogen atom economy. Suitable oxidants for the oxidation of halides are hydrogen peroxide and oxygen.

Oxidative Halogenation with "Green" Oxidants: Oxygen and Hydrogen Peroxide

Structurally dynamic polydisulfide networks that inherently exhibit both shape-memory and healable properties have been synthesized. These materials are semicrystalline, covalently cross-linked network polymers and as such exhibit thermal shape-memory properties. Upon heating above its melting temperature (Tm) films of the material can be deformed by a force. Subsequent cooling and removal of the force result in the material being “fixed” in this strained temporary shape through a combination of crystallinity and covalent cross-links until it is exposed to temperatures above the Tm at which point it recovers to its remembered processed shape. The incorporation of disulfide bonds, which become dynamic/reversible upon exposure to light or elevated temperatures, into these networks results in them being structurally dynamic upon exposure to the appropriate stimulus. Thus, by activating this disulfide exchange, the network reorganizes, and the material can flow and exhibit healable properties. Furthermore, ex...

Inherently Photohealable and Thermal Shape-Memory Polydisulfide Networks

The introduction of an O-acyl group at the α-position of carbonyl compounds is smoothly achieved using tetrabutylammonium iodide catalyst in the presence of hydrogen peroxide or tert-butyl hydroperoxide.

In situ generated (hypo)iodite catalysts for the direct α-oxyacylation of carbonyl compounds with carboxylic acids.

This Concept highlights the discovery and development of oxidative coupling reactions catalyzed by the hypoiodite (IO−) or iodite (OIO−) ion, which are generated in situ from iodide (I−) ion with hydrogen peroxide or tert‐butyl hydroperoxide as an environmentally benign oxidant. The most important features of these catalytic systems are 1) metal‐free oxidation, 2) milder reaction conditions, 3) high chemoselectivity (they tolerate a wide range of various functional groups), 4) operational simplicity, and 5) water or tert‐butyl alcohol as the only byproduct derived from the co‐oxidant used.

Catalysis with In Situ-Generated (Hypo)iodite Ions for Oxidative Coupling Reactions

https://www.rsc.org/suppdata/cc/c1/c1cc13568f/c1cc13568f.pdf

TBAI-catalyzed oxidative coupling of aminopyridines with β-keto esters and 1,3-diones—synthesis of imidazo[1,2-a]pyridines

Thiols were effectively oxidized into disulfides by reacting with hydrogen peroxide in the presence of a catalytic amount of iodide ion or iodine.

A Mild and Environmentally Benign Oxidation of Thiols to Disulfides

A mild and environmentally benign oxidation of thiols to disulfides, M. Kirihara, Y. Asai, S. Ogawa, T. Noguchi, A. Hatano, Y. Hirai,

Active methylene and methyne compounds can bechemoselectively brominated in high yields using potassiumbromide, hydrochloric acid, and hydrogen peroxide at room temper-ature. Key words: halogenation, halaides, green chemistry, bromination,active methylene compounds Halogenated active methylene and methyne compoundsare very important synthetic intermediates for the nucleo-philic substitutions in synthetic organic chemistry. Theclassical methods of halogenation of active methylene andmethyne compounds 1 are the reaction with bromine 1 orsulfuryl chloride, 2 however, they suffer from drawbackssuch as toxicity of the reagents, generation of acidicgasses after the reaction, or overhalogenation of thearomatic rings in 1 . Although a number of new methodsof this transformation have previously been developed,most of them have severe disadvantages such as theproduction of undesirable waste. 3–5 Khan and co-workers recently developed chemoselectivebromination of active methylene compounds by employ-ing the vanadium pentoxide catalyzed (V

Chemoselective Bromination of Active Methylene and Methyne Compounds by Potassium Bromide, Hydrochloric Acid and Hydrogen Peroxide

A Mild and Environmentally Benign Oxidation of Thiols to Disulfides.

A mild and environmentally benign oxidation of thiols to disulfides with a catalytic amount of molecular iodine or iodocation equivalent generated from iodide and hydrogen peroxide

Shiho Ogawa

Papers

A Mild and Environmentally Benign Oxidation of Thiols to Disulfides

A mild and environmentally benign oxidation of thiols to disulfides, M. Kirihara, Y. Asai, S. Ogawa, T. Noguchi, A. Hatano, Y. Hirai,

Chemoselective Bromination of Active Methylene and Methyne Compounds by Potassium Bromide, Hydrochloric Acid and Hydrogen Peroxide

A Mild and Environmentally Benign Oxidation of Thiols to Disulfides.

A mild and environmentally benign oxidation of thiols to disulfides with a catalytic amount of molecular iodine or iodocation equivalent generated from iodide and hydrogen peroxide