4,5,12,13-Tetrabromo[2.2]paracyclophane - A New Bis(aryne) Equivalent

The reaction of 2 with nBuLi at –78°C generates aryne intermediates within the aromatic rings of [2.2]paracyclophane which are trapped in Diels‐Alder reactions with dienes like furan, 1,9‐diphenylisobenzofuran, or cyclopentadiene. Reductive deoxygenation with low‐valent titanium reagents or TMSI converts the adducts of furan and isobenzofuran into anti‐[2.2]paracyclophanes 4 and 5, respectively. The reaction of two aryne intermediates with [2.2](2,5)furanophane (7) yields 8 with three [2.2]paracyclophane units arranged in a stair‐like fashion; yet, in this compound the highly shielded oxygen atoms cannot be removed anymore by reduction.