Synthese heterocyclischer Dialkine und deren Umsetzung mit CpCo(CO) 2

Synthesis of Heterocyclic Diynes and their Reaction with CpCo(CO) 2 The preparation of the heterocyclic diynes 1,6‐dithia‐3,8‐cyclodecadiyne ( 1b ), thia‐3,8‐cyclodecadiyne ( 11 ), 1‐thia‐6‐selana‐3,8‐cyclodecadiyne ( 12 ), oxa‐3,8‐cyclodecadiyne ( 13 ), 1,6‐dioxa‐3,8‐cyclodecadiyne ( 14 ), 1‐oxa‐6‐thia‐3,8‐cyclodecadiyne ( 15 ), 1,6‐diselena‐3,8‐cyclodecadiyne ( 26 ), thia‐3,9‐cyclounde‐cadiyne ( 22a ), thia‐3,13‐cyclopentadecadiyne ( 22b ) and its selena analogues 23a, 23b is described. The thia and monoselena compounds are obtained by a thia‐ or selenacyclization of the corresponding dibromides. Compound 26 has been obtained by a Misumi coupling reaction. The thiacycloalkadiynes of medium‐sized rings (10, 11) react with CpCo(CO) 2 to yield [2,2](2,5)thiophenophane derivatives. Acyclic thiadialkynes or thiacycloalkadiynes of larger ring size ( 22b ) with CpCo(CO) 2 by [2 + 2 + 2] cycloaddition.