Synthesis of Isothiocyanates: A Review.

Naturally occurring isothiocyanates are limited in number. These have been found to be present in some species of Cruciferae as progenitors, called glucosinolates, and are released from the injured plant by the enzyme myrosinase. On the other hand, there is a large number of synthetic isothiocyanates which constitute an important class of compounds. It is apparent that the chemistry of isothiocyanates has burgeoned over the years, and it continues to be a blossoming field. The attraction of isothiocyanates as synthons is obviously due to their diverse reactions and also due to their easy availability. It would not be out of place to record that, in comparison to isocyanates, their sulfur analogues, isothiocyanates, are less unpleasant and to some extent less hazardous to work with. In one of our investigations during 1984, we had to abandon the use of isocyanates as cyclocondensing agents because of the reluctance of a research scholar who was in the grip of a fear complex caused by the tragic death and crippling of a large number of Bhopal citizens due to the devastating accident in a chemical plant using methyl isocyanate. Since then we became interested in isothiocyanates. The purpose of this review is to present highlights of the various synthetic schemes to obtain the various kind of isothiocyanates. [ABSTRACT FROM AUTHOR]