Abstract
Ni(COD)(PMe3)2 catalyzes the cycloaddition of diphenylacetylene to the four-membered rings of linear [3]phenylene and its 2,3,7,8-tetrakis(trimethylsilyl) derivative. The reaction proceeds via initial formation of the 5,6-diphenylbenzo[3,4]cyclobuta[1,2-b]phenanthrene frame, followed by a competitive second, nonregioselective alkyne insertion to furnish the corresponding phenyl-substituted benzo[k]- and -[m]tetraphenes.
Key words
alkynes - arenes - cycloaddition - nickel - polycycles