Manganese porphyrin catalyzed cycloisomerization of enynes.
Cycloisomerization of 1,6-enynes to five- or six-membered ring systems is successfully carried out in the presence of a cationic manganese(III) catalyst. The use of a structurally rigid tetradentate porphyrin as the equatorial ligand and a weakly coordinating axial ligand is the key to bringing out the catalytic reactivity of manganese for the reaction. The axial ligand of the catalyst has a marked effect on the product and selectively aids the formation of five- or six-membered cyclic products.
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
Takuya
T
Ozawa
Takuya
T
Kurahashi
Seijiro
S
Matsubara