Synthesis of expanded planar dehydrobenzoannulenes: Weakly diatropic, weakly paratropic, or atropic?

Article abstract of DOI:10.1016/S0040-4039(98)01583-4

Use of a Cu/Pd cross-coupling strategy has led to the synthesis of the first dehydrobenzoannulenes containing triacetylenic linkages. NMR studies of these macrocycles and comparison with other known systems indicate that, in spite of their large size and extensive benzannelation, dehydrobenzoannulenes possess weak induced ring currents.