Starting from the early 1990’s, the chemistry of polyvalent iodine organic compounds has experienced an explosive development. This surging interest in iodine compounds is mainly due to the very useful oxidizing properties of polyvalent organic iodine reagents, combined with their benign environmental character and commercial availability. Iodine(III) and iodine(V) derivatives are now routinely used in organic synthesis as reagents for various selective oxidative transformations of complex organic molecules. Several areas of hypervalent organoiodine chemistry have recently attracted especially active interest and research activity. These areas, in particular, include the synthetic applications of 2-iodoxybenzoic acid (IBX) and similar oxidizing reagents based on the iodine(V) derivatives, the development and synthetic use of polymer-supported and recyclable polyvalent iodine reagents, the catalytic applications of organoiodine compounds, and structural studies of complexes and supramolecular assemblies of polyvalent iodine compounds.

The chemistry of polyvalent iodine has previously been covered in four books1–4 and several comprehensive review papers.5–17 Numerous reviews on specific classes of polyvalent iodine compounds and their synthetic applications have recently been published.18–61 Most notable are the specialized reviews on [hydroxy(tosyloxy)iodo]benzene,41 the chemistry and synthetic applications of iodonium salts,29,36,38,42,43,46,47,54,55 the chemistry of iodonium ylides,56–58 the chemistry of iminoiodanes,28 hypervalent iodine fluorides,27 electrophilic perfluoroalkylations,44 perfluoroorgano hypervalent iodine compounds,61 the chemistry of benziodoxoles,24,45 polymer-supported hypervalent iodine reagents,30 hypervalent iodine-mediated ring contraction reactions,21 application of hypervalent iodine in the synthesis of heterocycles,25,40 application of hypervalent iodine in the oxidation of phenolic compounds,32,34,50–53,60 oxidation of carbonyl compounds with organohypervalent iodine reagents,37 application of hypervalent iodine in (hetero)biaryl coupling reactions,31 phosphorolytic reactivity of o-iodosylcarboxylates,33 coordination of hypervalent iodine,19 transition metal catalyzed reactions of hypervalent iodine compounds,18 radical reactions of hypervalent iodine,35,39 stereoselective reactions of hypervalent iodine electrophiles,48 catalytic applications of organoiodine compounds,20,49 and synthetic applications of pentavalent iodine reagents.22,23,26,59

The main purpose of the present review is to summarize the data that appeared in the literature following publication of our previous reviews in 1996 and 2002. In addition, a brief introductory discussion of the most important earlier works is provided in each section. The review is organized according to the classes of organic polyvalent iodine compounds with emphasis on their synthetic application. Literature coverage is through July 2008.

Chemistry of Polyvalent Iodine

Chiral Salen Complexes: An Overview to Recoverable and Reusable Homogeneous and Heterogeneous Catalysts

Dyes adsorption using clay and modified clay: A review

Cyclic organic carbonates represent a relevant class of chemicals that can be prepared from CO2 by cycloaddition to epoxides. The application of efficient catalysts is crucial in allowing the cycloaddition reaction to proceed under very mild conditions of temperature, pressure, and CO2 concentration, thus resulting in a sustainable and carbon-balanced approach to CO2 conversion. This is particularly the case if impure waste CO2 could be employed as a feedstock. In this Review, we have critically analyzed the burgeoning literature on the cycloaddition of CO2 to epoxides with the aim to provide state-of-the-art knowledge on the catalysts that can convert CO2 to carbonates under ambient conditions. These have been systematically organized in families of compounds and critically scrutinized in terms of catalytic activity, availability and mechanistic features. Finally, we provide an overview on the catalytic systems able to function using diluted and impure CO2 as a feedstock.

Catalytic Strategies for the Cycloaddition of Pure, Diluted, and Waste CO2 to Epoxides under Ambient Conditions

Biomass and waste exhibit great potential for replacing fossil resources in the production of chemicals. The search for alternative reaction media to replace petroleum-based solvents commonly used in chemical processes is an important objective of significant environmental consequence. Recently, bio-based derivatives have been either used entirely as green solvents or utilized as pivotal ingredients for the production of innovative solvents potentially less toxic and more bio-compatible. This review presents the background and classification of these new media and highlights recent advances in their use in various areas including organic synthesis, catalysis, biotransformation and separation. The greenness, advantages and limitations of these solvents are also discussed.

Bio-based solvents: an emerging generation of fluids for the design of eco-efficient processes in catalysis and organic chemistry

Schiff base-derived homogeneous and heterogeneous palladium catalysts for the Suzuki–Miyaura reaction

This paper describes a simple in-situ process of synthesizing highly dispersed palladium nanoparticles (PdNPs) using aqueous leaf extract of GarciniapedunculataRoxb as bio-reductant and starch (03%) as bio-stabilizer The PdNPs are characterized by techniques like FTIR, TEM, SEM-EDX, XRD and XPS analysis It is worthnoting thatwhen the synthesis of nanoparticles was carried out in absence of starch, agglomeration of particles has been noticedThe starch-assisted PdNPs showed excellent aqueous-phase catalytic activities for three important reactions: the Suzuki-Miyaura cross-coupling reactions of aryl halides (aryl bromides and iodides) with arylboronic acids; selective oxidations of alcohols to corresponding carbonyl compounds; and reduction of toxic Cr(VI) to nontoxic Cr(III) Our catalyst could be reused up to four cycles without much compromising with its activity Furthermore, the material also demonstrated excellent antimicrobial and anti-biofilm activities against a novel multidrug resistant clinical bacterial isolate Cronobactersakazakii strain AMD04 The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PdNPswere found to be 006 and 012 mM respectively

/pdf/biogenic-synthesis-of-palladium-nanoparticles-and-their-2alcvdp1xi.pdf

Biogenic synthesis of palladium nanoparticles and their applications as catalyst and antimicrobial agent.

A highly efficient Schiff-base derived palladium catalyst for the Suzuki–Miyaura reactions of aryl chlorides

An in situ-generated catalytic system based on PdCl2 and primary amine-based ligand exhibited excellent activity (up to 98% isolated yield) in the Suzuki–Miyaura cross-coupling reactions of aryl bromides with arylboronic acids in water, at room temperature, without any additive. The efficiencies of the ligands follow the order: (C6H5)3CNH2 > C6H5CH2 NH2 > C6H5 NH2 > C6H11 NH2, which is in accordance with the palladacycle forming capacity of the respective ligands. Moderate-to-good yields (up to 78% isolated yield) of the coupling products were also obtained with less reactive aryl chlorides as substrates at room temperature in isopropanol using an alternative protocol based on Pd(OAc)2 and (C6H5)3CNH2. Copyright © 2011 John Wiley & Sons, Ltd.

Pankaj Das

Papers

Schiff base-derived homogeneous and heterogeneous palladium catalysts for the Suzuki–Miyaura reaction

Biogenic synthesis of palladium nanoparticles and their applications as catalyst and antimicrobial agent.

A highly efficient Schiff-base derived palladium catalyst for the Suzuki–Miyaura reactions of aryl chlorides

Highly efficient amine‐based catalytic system for room temperature Suzuki–Miyaura reactions of aryl halides with arylboronic acids

Triphenylphosphine chalcogenides as efficient ligands for room temperature palladium(II)-catalyzed Suzuki–Miyaura reaction