Synthesis of hydrophenanthrenes through a ‘green’ Fischer carbene–alkyne coupling process

Coupling of alkynylbenzoyl systems with γ,δ-unsaturated Fischer carbene complexes leads to the formation of hydrophenanthrene derivatives. This reaction is not affected by aqueous systems, which offer a further advantage such that chromium hexacarbonyl sublimes during the reaction process. Chromium carbene–alkyne coupling processes can thus be performed in environmentally friendly solvents with substoichiometric net consumption of chromium hexacarbonyl.