One-pot synthesis of 4-methyl-3,4-dihydrothiopyran derivatives is accomplished from 4-hydroxydithiocoumarins/4-hydroxy-2H-chromene-2-thione and vinyl ethers in the presence of CuI with the formation of two C–C bonds and one C–S bond.
The regioselective synthesis of 2-aryl-2H,5H-thiopyrano[2,3-b]thiochromen-5-ones was achieved using 4-hydroxydithiocoumarins and substituted cinnamaldehydes under metal-free conditions.
The synthesis of fused chromono-thiophenes and -thiopyrans are achieved from 4-hydroxythiocoumarin derivatives utilising simple alkylation followed by [3,3]-sigmatropic rearrangement and subsequent solvent-dependent divergent ring closure reactions.
In this review, we provide a comprehensive overview of the synthesis of thiopyran family compounds via cycloaddition reactions, with examples spanning from the year 2000 to the present.
The green one-pot cascade synthesis of thiopyrano[2,3-b]indoles and investigations into their preliminary optoelectronic properties are described.