Recent advances in the chemistry of selenopheno[3,2-b]selenophenes and their analogues

When two selenophene rings fuse at their b-edge, they form two unique structural isomers: selenopheno[2,3-b]selenophene and selenopheno[3,2-b]selenophene. This fusion enhances molecular conjugation, leading to distinct chemical and physical properties, such as improved electron delocalization compared to a single selenophene ring. Selenopheno[3,2-b]selenophenes are of particular interest in materials science due to their potential in organic semiconductors and luminescent materials. The synthesis of selenopheno[3,2-b]selenophene, along with related compounds like diselenopheno[3,2-b:2′,3′-d]selenophene and selenopheno[3,2-b]selenopheno[2′,3′:4,5]selenopheno[2,3-d]selenophene, can be accomplished using various methods. These include (i) Suzuki-Miyaura coupling, (ii) Stille coupling, (iii) Sonogashira coupling, (iv) McMurry cyclization, (v) Wittig reaction, (vi) Thorpe–Ziegler cyclization, and (vii) photocyclization reactions, among other techniques.