Development of a Coordinatively Unsaturated Chiral Indenylruthenium Catalyst.

An unprecedented coordinatively unsaturated chiral indenylruthenium complex 12 was designed and synthesized to provide additional coordination sites for Ru-catalyzed asymmetric transformations. In an attempt to catalyze an asymmetric enyne cycloisomerization reaction of 1,6-enyne, significant amounts of hydroxycyclization were observed. Up to 84:16 er of the hydroxycyclization product was obtained in 2-MeTHF. This chiral indenylruthenium catalyst could also perform an asymmetric redox isomerization/C-H insertion reaction in up to 90:10 er.