Palladium-catalysed polycyclization of dienynes to give carbocyclic angularly bisanellated cyclohexadlene derivatives

Abstract

Various 2-bromododeca-1,11-dien-6-ynes 1a,b,8 and trans- or cis-10a,b when subjected to Heck reaction conditions, cleanly undergo palladium-catalysed biscyclizations followed by an electrocyclic rearrangement to form tricyclic cyclohexadienes 5a,b, 9 and cis- or trans-11a,b as sole products (7 examples).