There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

The preparation, structure, and chemistry of hypervalent iodine compounds are reviewed with emphasis on their synthetic application. Compounds of iodine possess reactivity similar to that of transition metals, but have the advantage of environmental sustainability and efficient utilization of natural resources. These compounds are widely used in organic synthesis as selective oxidants and environmentally friendly reagents. Synthetic uses of hypervalent iodine reagents in halogenation reactions, various oxidations, rearrangements, aminations, C–C bond-forming reactions, and transition metal-catalyzed reactions are summarized and discussed. Recent discovery of hypervalent catalytic systems and recyclable reagents, and the development of new enantioselective reactions using chiral hypervalent iodine compounds represent a particularly important achievement in the field of hypervalent iodine chemistry. One of the goals of this Review is to attract the attention of the scientific community as to the benefits of...

Advances in Synthetic Applications of Hypervalent Iodine Compounds

https://www.pnas.org/content/pnas/90/5/1635.full.pdf

Supramolecular chemistry.

The aim of this review is to summarize the various naturally occurring chalcone compounds which have been isolated from different plants. Chalcones considered as obligate intermediated in flavonoid biosynthesis but they do not accumulate to appreciable degree in most plants. The largest number of natural chalcones has been isolated from species of the Leguminosae, Asteraceae and Moraceae families. Chalcone accumulating plants have often been used in traditional medicine and chalcones have therefore been studied and reported to possess many beneficial biological effects including anti-inflammatory, antimicrobial, antifungal, antioxidant, cytotoxic, antitumor and chemopreventive activities. Previously published reviews on this topic survey the biological activities of natural and synthetic chalcones but there are no comprehensive contributions on occurrence and biological activities of natural chalcones. The present study provides an overview of hydroxy or/and methoxy-substituted chalcones, methylated, prenylated, geranylated and other monomeric derivatives, chromeno- and furanochalcones, dimeric chalcones and dihydrochalcone derivatives focusing on their biosynthesis, natural sources and biological activities. On the basis of 608 references, this review covers the phytochemistry and biological activity of natural chalcones, describing 646 compounds have been appeared in the literature since 1975. The summary is aimed to initiate further pharmacobotanical, biotechnological and medicinal studies on the field of chalcone research. This contribution reviews some of the general aspects of naturally occurring chalcones including their chemical categories, focusing on plant sources and biological activities. The review covers the major works appeared in the literature from 1975 up to 2014, relating to 608 references and 646 compounds.

Asok K. Mallik

Papers

Pongaglabol, a new hydroxyfuranoflavone, and aurantiamide acetate, a dipeptide from the flowers of Pongamia glabra

Isopongaglabol and 6-methoxyisopongaglabol, two new hydroxyfuranoflavones from Pongamia glabra

Synthesis of flavanones by use of anhydrous potassium carbonate as an inexpensive, safe, and efficient basic catalyst

On the chemistry of indian orchidaceae plants—II

A chromenoflavanone and two caffeic esters fromPongamia glabra