"Stereoselective Formation and Opening of Aromatic Rings"

Due to the unfavorable energetics in breaking aromaticity during ring opening, catalytic
aromatic ring cleavage remained largely unfeasible. In contrast, alkene metathesis catalyzed
by transition-metal alkylidenes is established as one of the most versatile C=C bond forming
and breaking reactions for non-aromatic structures. Despite remarkable advances, strategies
to open aromatic compounds by metathesis remain elusive. After highlighting methods for
stereoselective arene formation, this talk will discuss the cleavage of aromatic rings by
aromatic ring-opening metathesis (ArROM) by using Schrock–Hoveyda molybdenum catalysts.
With different ring systems, the reactions proceed through unique alkylidene intermediates.
Furthermore, the possibility for stereoselec0ve ArROM with exquisite catalyst control over the
configuration of atropisomers will be presented. Overall, these methods will highlight that
ArROM is a viable and efficient approach to catalytically transform and interconvert various
aromatics without the requirement for any reagents or photoexcitation.
Nature 2025, 638, 697–703.