Synthesis and Properties of Carbo- and Heterocyclic Benz[ a ]azulenes.

A new and convenient synthesis of aryl-substituted naphtho[2,1- a ]azulenes by the combination of Suzuki-Miyaura, Sonogashira, and cycloisomerization reactions is reported. The methodology was applied to the synthesis of hitherto unknown azuleno[1,2- h ]quinolines, cyclohepta[1,2]indeno[4,5- b ]thiophenes, and cyclohepta[1,2]indeno[4,5- c ]thiophenes. The impact of different fused-heterocyclic rings on the photophysical and electrochemical properties of these azulene derivatives was studied by experimental and theoretical methods and hence provides a rationale for the preparation of novel azulene derivatives with improved properties for application as organic materials.