Journal of the American Chemical Society, Vol.131, No.18, 6348-6348, 2009
Ligand-Controlled Access to [4+2] and [4+3] Cycloadditions in Gold-Catalyzed Reactions of Allene-Dienes
By adjustment of the electronic properties of the ancilliary ligands, high selectivity can be achieved for either [4 + 2] or [4 + 3] cycloaddition reactions of allene-dienes catalyzed by gold(I). Triarylphosphitegold(I) complexes are employed as catalysts for a [4 + 2] cycloaddition reaction leading to alkylidenecyclohexenes. Conversely, di-tert-butylbiphenylphosphinegold (I)-catalyzed reactions afford cycloheptadienes via [4 + 3] cycloaddition reactions.