ABSTRACT
Isatin (1H-indole-2,3-dione, indoline-2,3-dione) 1 (Figure 4.1) is a structurally simple natural product found in the plants of genus Isatis and in Couropita guianancis aubl (Bergman et al. 1988, Silva et al. 2001). It has also been found as a metabolic derivative of adrenaline in humans (Chiyanzu et al. 2003, Almeida et al. 2010). Isatin, possessing an indole motif with a ketone and a γ-lactam moiety fused to the benzene ring, has drawn considerable interest to the researchers in the eld of organic synthesis and medicinal chemistry. Isatin undergoes electrophilic aromatic substitutions at positions C-5 and C-7 of its benzene ring (Silva et al. 2001). N-Alkylations/arylations/acylations, nucleophilic additions at the carbonyl group, chemoselective reductions, oxidations, and ring expansion are also reported. The diverse reactivity of isatin has made it a valuable building block for the synthesis of various other heterocyclic frameworks such as quinolines, indoles, oxindole, and β-lactams, etc. The chemistry of isatin has been reviewed in the past by Sumpter (1944), Popp (1975), Mesropyan and Avetisyan (2009), and Silva et al. (2001). Recent literature shows resurgence of interest in the chemistry and bioactivity of isatin and its derivatives leading to improvement in several already known reactions and synthesis of many isatin derivatives with different types of biological activity (Pandeya et al. 2005). Isatin derivatives having antitubercular activity have been reviewed recently (Aboul-Fadl and Bin-Jubair 2010). This chapter is based on the chemistry of isatin reported from 2000 to 2010. Some examples from early 2011 are also included.
