Fragmentation of 1,4,2-Oxathiazole Derivative to Provide Anticancer Isothiocyanates Product: Is the C-5 and C-3 Substituent Responsible?

Abstract

Isothiocyanates (ITCs) was recognized as anticancer properties, few attempts that were performed to prepare this product through exploiting the relative sensitivity of 1,4,2-oxathiazole derivative utilizing fragmentation process, for which some pertinent features as temperature and substituent were considered as a key role of such procedure. With the aid of most appropriate theoretical methods, we have remarked that the presence of electron-releasing substituents such as, N > O > S > C, at C-5 as well as electron-releasing substituents corresponding to an aliphatic group at the position C-3 are in high performance on the fragmentation of 1,4,2-oxathiazole derivatives. At this stage, we suggest that the substituent at the position C-5 should be responsible for the lengthening and weakening of C-S and ON interatomic bond, while the substituents at the position C-3 play a principal factor to stability of the ITCs products, besides both substituents have successfully reduced the involved temperature. Likewise, ELF analysis shows that the weakening and cleavage of C-S bond is a direct consequence of the lone pairs electron donation associated with the nucleophilic atom substituent to the C5-S σ* orbital.