The major synthetic routes for thiopyran-fused heterocycles published in the period 2013–2024 have been reviewed.
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.
Water-mediated synthesis of 3,6-dihydro-2H-thiopyrans from diallyl sulfides and diazo compounds via Doyle–Kirmse reaction induced by blue-LEDs and ring-closing metathesis.
A theoretical study of the IEDDA reaction of endo-BCN with 2H-pyran-2-one, 2H-thiopyran-2-one, 2H-pyran-2-thione and 2H-thiopyran-2-thione reveals the superior reactivity of 2H-pyran-2-thiones because of the lower distortion energy.
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.