An efficient one pot three-component nanocatalyzed synthesis of spiroheterocycles using TiO2 nanoparticles as a heterogeneous catalyst

An efficient and environmentally benign isocyanide based domino protocol has been presented for the synthesis of structurally diverse spiroheterocycles, spiroannulated with imidazothiazole and imidazothiadiazole, involving the three component reaction of 2-aminobenzothiazole/2-amino-1,3,4-thiadiazole, cyclohexyl/tert-butyl isocyanides and isatines/cyclic carbonyl compounds catalyzed by recyclable and reusable nanocrystalline TiO2.