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 methodologywas 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 photophysicaland electrochemical properties of these azulene derivatives was studiedby experimental and theoretical methods and hence provides a rationalefor the preparation of novel azulene derivatives with improved propertiesfor application as organic materials.