The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

The Halogen Bond

Odd-electron, redox-active ligands are discussed in the context of catalysis. We focus on ligand-based, non-singlet state intermediates and their participation in catalytic processes and related stoichiometric transformations.

Redox-active ligands in catalysis

In the twelve years since the first review article dealing with chemical constituents of the Hepaticae appeared in this series as Volume 42 (19), several short reviews concerned with chemical constituents of bryophytes have been published (22, 96, 144, 265, 271, 647, 649, 650) In 1988, a Symposium on Chemistry and Chemical Taxonomy of Bryophytes was organised on the behalf of the Phytochemical Society of Europe; the proceedings of this meeting appeared as a book entitled Bryophytes: Their Chemistry and Chemical Taxonomy (651) The symposium concerned itself with phytochemical, biochemical, botanical, chemotaxonomical, pharmaceutical, biotechnological and environmental aspects of bryophytes as well as with the synthesis of the terpenoids and aromatic compounds bryophytes elaborate The physiological and biochemical aspects of bryophytes have also been described in a recent book Bryophytes Development: Physiology and Biochemistry (139)

Chemical Constituents of the Bryophytes

Encyclopedia Reagents in organic synthesis

Iodine was discovered as a novel element in 1811 during the Napoleonic Wars. To celebrate the bicentennial anniversary of this event we reflect on the history and highlight the many facets of iodine research that have evolved since its discovery. Iodine has an impact on many aspects of life on Earth as well as on human civilization. It is accumulated in high concentrations by marine algae, which are the origin of strong iodine fluxes into the coastal atmosphere which influence climatic processes, and dissolved iodine is considered a biophilic element in marine sediments. Iodine is central to thyroid function in vertebrates, with paramount implications for human health. Iodine can exist in a wide range of oxidation states and it features a diverse supramolecular chemistry. Iodine is amenable to several analytical techniques, and iodine compounds have found widespread use in organic synthesis. Elemental iodine is produced on an industrial scale and has found a wide range of applications in innovative materials, including semiconductorsin particular, in solar cells.

Commemorating two centuries of iodine research: An interdisciplinary overview of current research

The data on the use of silica gel in organic synthesis are presented. Some specific features of cyclisation (both intra- and intermolecular) reactions, rearrangements, reduction, oxidation, condensation, formylation, hydration and dehydration, protection of functional groups, etc., in the presence of silica gel, are discussed. The bibliography includes 96 references.

https://iopscience.iop.org/article/10.1070/RC2001v070n11ABEH000642/pdf

Silica gel in organic synthesis

Commercially available iodine has played an important role in organic synthesis. This review discusses the versatile uses of iodine in different chemical transformations. Reactions include esterification, cycloaddition reaction, allylation of aldehydes, acetalization of carbonyl compounds, acylation of alcohols, synthesis of cyclic ethers and aromatization of α,β-unsaturated ketones.

/pdf/iodine-in-organic-synthesis-2gwpo0gggi.pdf

Iodine in organic synthesis

Iodolactonization: Past and Present Examples

Data on procedures for protection of the carbonyl group by its conversion into the 1,3-dithiolane moiety and on cleavage of the latter under the action of different reagents are surveyed. The preparation of 1,3-dithiolanes from carbonyl compounds followed by deprotection can be used in syntheses of various organic compounds. The bibliography includes 54 references.

Ajoy K. Banerjee

Papers

Silica gel in organic synthesis

Iodine in organic synthesis

Iodolactonization: Past and Present Examples

Reagents for the preparation and cleavage of 1,3-dithiolanes

Synthesis of terpenoid compounds from α-santonin