A. Kotali
Jan 1, 2005
Citations
0
Influential Citations
5
Citations
Journal
Molecules : A Journal of Synthetic Chemistry and Natural Product Chemistry
Abstract
Iodine was discovered in 1811 by French chemist Bernard Courtois and it was named by J. L. Gay Lussac in 1813. Its name derives from the Greek word iodes, meaning "violet-colored," reflecting both the characteristic lustrous, deep purple color of resublimed crystalline iodine as well as the colour of its vapour. It can be found in seaweed and brine wells. From the early beginning it found extremely useful applications in everyday life. It is known that potassium iodide was used as a remedy for goiter (Derbyshire neck), an enlargement of the thyroid gland, as early as 1819. The thyroid is responsible for the production of thyroxine, a metabolism-regulating hormone. Iodine is an essential trace element for humans and plays an important role in many biological organisms. Among the most common everyday uses of iodine is in halogen lamps, in ink pigments and as a topical antiseptic to kill bacteria. Because iodine is the largest, least electronegative and most polarisable of the common halogens, it is capable of forming stable polycoordinate high-valent (with a value of up to 7, IF 7) compounds. The most common polyvalent organic iodine compounds are I(III) and I(V) species. Since the first stable polyvalent organic iodine compound, the trivalent PhICl 2 , was prepared by the German chemist C. H. C. Willgerodt in 1886, this field has experienced a great development. Hypervalent iodine compounds have been extensively used for a variety of chemical transformations and particularly as oxidative reagents. (Diacetoxyiodo)benzene, [bis-(trifluoro-acetoxy)iodo]benzene, [hydroxy(tosyloxy)iodo]benzene, iodosylbenzene, the Dess-Martin reagent and 1-hydroxy-1,2-benziodoxol-3(1H)-one 1-oxide are some of the most useful and popular contemporary polyvalent organoiodine compounds. Polymer-supported (diacetoxyiodo)benzene has also found interesting synthetic applications recently. Because of their ready availability, their convenience of use and their unique and sometimes selective oxidizing properties (e.g. Dess-Martin periodinane) they are widely employed in the synthesis of complex natural products of biological and medicinal interest. Another area of significant importance are the various reagents which are very useful for the transfer of aryl, alkenyl, alkynyl and aryne groups. The fact that alkynyliodonium salts may serve as electrophilic acetylene equivalents engendered a renaissance in polyvalent organoiodine chemistry. A