A novel scandium ortho-methoxynitrosobenzene-dimer complex: mechanistic implications for the nitroso-Diels-Alder reaction.

Arylnitroso dienophiles exist in equilibrium with their dimeric counterparts, which in turn form stable bidentate complexes with scandium(III) triflate and react with cyclohexadiene to give the corresponding Diels-Alder adduct at the same rate as the normal thermal process.