TETRAHALOBENZENES AS DI-ARYNE EQUIVALENTS IN POLYCYCLIC ARENE SYNTHESIS

Article abstract of DOI:10.1016/S0040-4020(01)87696-1

1,2,4,5-Tetrabromobenzenes and analogous naphthalenes react with one or two equivalents of n-butyllithium and various dienes (furans, pyroles, cyclopentadienes, fulvenes) to form mono- or bis-cycloadducts.Highly substituted arenes can be obtained by removing the oxygen or nitrogen bridges from the furan or pyrrole adducts.By choice of conditions, two identical or two different rings can be fused to the di-aryne equivalent.Improved short syntheses of permethylnaphthalene, -anthracene and -naphthacene are described.A new triphenylene synthesis is presented.