title: Enantio- and Regioselective Ir-Catalyzed Hydrogenation of Di- and Trisubstituted Cycloalkenes.
abstract: A number of cyclic olefins were prepared and evaluated for the asymmetric hydrogenation reaction using novel N,P-ligated iridium imidazole-based catalysts (Crabtree type). The diversity of these cyclic olefins spanned those having little functionality to others bearing strongly coordinating substituents and heterocycles. Excellent enantioselectivities were observed both for substrates having little functionality (up to >99% ee) and for substrates possessing functional groups several carbons away from the olefin. Substrates having functionalities such as carboxyl groups, alcohols, or heterocycles in the vicinity of the C═C bond were hydrogenated in high enantiomeric excess (up to >99% ee). The hydrogenation was also found to be regioselective, and by controlling the reaction conditions, selective hydrogenation of one of two trisubstituted olefins can be achieved. Furthermore, trisubstituted olefins can be selectively hydrogenated in the presence of tetrasubstituted olefins.
authors.affiliation: Department of Organic Chemistry, Stockholm University, Arrhenius-laboratory , 10691 Stockholm, Sweden.
authors.forename: Byron K
authors.initials: BK
authors.lastname: Peters
authors.affiliation: Department of Organic Chemistry, Stockholm University, Arrhenius-laboratory , 10691 Stockholm, Sweden.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Organic Chemistry, Stockholm University, Arrhenius-laboratory , 10691 Stockholm, Sweden.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Margarita
authors.affiliation: Department of Organic Chemistry, Stockholm University, Arrhenius-laboratory , 10691 Stockholm, Sweden.
authors.forename: Wangchuk
authors.initials: W
authors.lastname: Rabten
authors.affiliation: Department of Organic Chemistry, Stockholm University, Arrhenius-laboratory , 10691 Stockholm, Sweden.
authors.forename: Sutthichat
authors.initials: S
authors.lastname: Kerdphon
authors.affiliation: Department of Organic Chemistry, Stockholm University, Arrhenius-laboratory , 10691 Stockholm, Sweden.
authors.forename: Alexander
authors.initials: A
authors.lastname: Orebom
authors.affiliation: Department of Organic Chemistry, Stockholm University, Arrhenius-laboratory , 10691 Stockholm, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Morsch
authors.affiliation: Department of Organic Chemistry, Stockholm University, Arrhenius-laboratory , 10691 Stockholm, Sweden.
authors.forename: Pher G
authors.initials: PG
authors.lastname: Andersson