Facile Carbolithiation of Bent Alkyne without Catalyst.Tandem Route to Dibenzo[b,f]pentalenes from Dibenzocyclooctadiyne

摘要

Nucleophilic addition of RLi to a triple bond of dibenzocy-cloocta[a,e]diyne provides dibenzo[b,f]pentalene motif through trans-annulation of the resulting vinyllithium.Dibenzopentalene anion thus formed reacts with various electrophiles such as aldehydes,alkyl halides,acid halide,and Me3SiCl to give the corresponding products.