Synthesis of 2- and 6-thienylazulenes by palladium-catalyzed direct arylation of 2- and 6-haloazulenes with thiophene derivatives†
Abstract
Preparation of 2- and 6-thienylazulene derivatives was established by the palladium-catalyzed direct cross-coupling reaction of 2- and 6-haloazulenes with the corresponding thiophene derivatives in good yield. Several thienylazulene derivatives were also used in the reaction with 2-chloroazulene derivatives in the presence of the palladium-catalyst to afford the thiophene derivatives with two azulene functions in good yield.