Recent Advances in the Chemistry of Selenopheno[2,3‐ <i>b</i> &amp;3,4‐ <i>b</i> &amp;3,4‐ <i>c</i> ]selenophenes and Their Analogues

ABSTRACT The fusion of two selenophene ring systems results in five distinct structural types: condensed selenopheno[2,3‐ b ]selenophene, selenopheno[3,4‐ b ]selenophene, 1 H ,4 H ‐selenopheno[3,4‐ c ]selenophene, 1 H ,3 H ‐selenopheno[3,4‐ c ]selenophene, and selenopheno[3,2‐ b ]selenophene. Despite their potential, no dedicated studies have exclusively explored this scaffold, which has primarily been employed as a versatile building block across various applications. The synthesis of selenopheno[2,3‐ b &amp;3,4‐ b &amp;3,4‐ c ]selenophene and their analogs can be achieved through diverse chemical approaches, including (i) selenation reactions, (ii) Thorpe–Ziegler cyclization, (iii) Stille and Sonogashira coupling, (iv) McMurry cyclization, and (v) Photocyclization reactions, among other methods.