Facile one-pot, multi-component reaction to synthesize spirooxindole-annulated thiopyran derivatives under environmentally benevolent conditions

Regio- and diastereoselective synthesis of thioxothiazolidin- indolin-2-ones, oxoindolin-carbamodithioate hybrids, and their base-catalyzed conversion into dispirocyclopentanebisoxindoles

“…The general procedure used for synthesizing product 3a was also employed for compound 4a, except using dimethylamine in place of methylamine (Table 1, entry 13). To our surprise, products 3a and 4a were easily converted to dispirocyclopentanebisoxindoles (5a-5d) under basic conditions (Table 1, entries [15][16][17][18][19][20][21][22][23][24][25]. This conversion proceeded well in the presence of different bases such as LDA, KOH, NaOH, and K 2 CO 3 via one-pot operation after 30-90 min of stirring.…”

“…A straightforward approach to synthesizing S-heterocycles is exploiting dithiocarbamates. [24][25] The great nucleophilic strength of dithiocarbamates has made them widely used in organic transformations. For example, Alizadeh and coworkers reported a thermodynamic approach for synthesizing 2',3 '-dihydro-2'thioxospiro[indole-3,6'-[1,3]-thiazin]-2(1H)-ones derivatives using dithiocarbamates at re ux conditions.…”

Update on thiopyran-fused heterocycle synthesis (2013–2024)

“…In another report, Moghaddam et In a more recent report, the same group showed the fivecomponent reaction between methylamine 43, carbon disulfide 44, malononitrile 18 and isatin 17 in ethanol solvent at 25 °C to yield product 45 (Scheme 8). 26 In this reaction, instead of using indoline-2-thione as bis-nucleophile, they used carbamodithioic acid, generated by the reaction of primary amine 43 with carbon disulfide 44.…”

Regio- and diastereoselective synthesis of thioxothiazolidin-indolin-2-ones, oxoindolin-carbamodithioate hybrids, and their base-catalyzed conversion into dispirocyclopentanebisoxindoles

“…On the other hand, from the distant past to the present, S-heterocycles have maintained their importance as an essential part and core of FDA-approved drugs and medicinally active molecules. A straightforward approach to synthesizing S-heterocycles is exploiting dithiocarbamates 24 , 25 . The great nucleophilic strength of dithiocarbamates has made them widely used in organic transformations.…”