A six-membered and two seven-membered cycloalkynes, namely 1 – 3, are generated by matrix photolyses of the corresponding cyclopropenones 4 – 6 at about 15 K and characterized by spectroscopic means and in two cases by identification of the trimerization products 9 and 10.
Ring‐Expanding Rearrangement of Benzo‐Fused Tris‐Cycloheptenylenes towards Nonplanar Polycyclic Aromatic Hydrocarbons
作者:Barbara Ejlli、Frank Rominger、Jan Freudenberg、Uwe H. F. Bunz、Klaus Müllen
DOI:10.1002/chem.202203735
日期:2023.3.13
Based on a benzannulated tris-tropone, a hexabrominated precursor containing three heptagons connected by a benzene ring was accessible in onestep. Subsequent π-extension afforded four negatively curved and overcrowded PAHs consisting of two heptagons and one octagon as a consequence of a ring-expanding 1,2-rearragement during the Suzuki couplings.