An efficient green chemical approach for the synthesis of structurally diverse spiroheterocycles with fused heterosystems

α-Aminoazoles/azines: key reaction partners for multicomponent reactions

“…This method involves heating a reaction mixture containing isatin 142, various cyclic 1,3-diketones 122 and 2-aminobenzothiazole 3b in aqueous medium in the presence of 10 mol% sulfamic acid at 80 °C for 12–55 min to afford the corresponding spiroheterocycles 157 ( Scheme 50 ). 119 …”

Synthesis and characterization of terbium doped TiO2 nanoparticles and their use as recyclable and reusable heterogeneous catalyst for efficient and environmentally sustainable synthesis of spiroannulated indolo[3,2‐c]quinolines‐ mimetic scaffolds of isocryptolepine

“…The present synthetic methodology involves the reaction of phenylhydrazine, with o-aminoacetophenone and cyclic ketones using nanostructured Terbium doped TiO 2 as recyclable and reusable heterogeneous catalyst. In view of medicinal importance of isocryptolepine structural framework and our research interest in the synthesis of drug-like hybrid molecules with privileged heterocyclic structures, [34][35][36][37][38][39][40][41][42][43][44][45] the present synthetic protocol is probably the first report for the synthesis of spiroannulated indolo […”

Synthesis of Substituted Isatins from the MBH Adduct of 1,5,6-Trisubstituted Isatins Using (2,4-Dinitrophenyl)hydrazine and K-10 Clay Explored as Protection–Deprotection Chemistry

“…The chemistry of indoline-2,3-dione (isatin) − functionalization at the 1,3,4,5,6-positions leads to attractive applications among major classifications of chemical, biological, and medicinal fields of science. Functionalization of these positions is well established in the literature, such as Morita–Baylis–Hillman addition reaction − (MBH adduct formation at C-3 position), substitution reactions ( N -alkylation, aromatic electrophilic substitution), oxidation, and reduction.…”