title: Chiral hetero- and carbocyclic compounds from the asymmetric hydrogenation of cyclic alkenes.
abstract: Several types of chiral hetero- and carbocyclic compounds have been synthesized by using the asymmetric hydrogenation of cyclic alkenes. N,P-Ligated iridium catalysts reduced six-membered cyclic alkenes with various substituents and heterofunctionality in good to excellent enantioselectivity, whereas the reduction of five-membered cyclic alkenes was generally less selective, giving modest enantiomeric excesses. The stereoselectivity of the hydrogenation depended more strongly on the substrate structure for the five- rather than the six-membered cyclic alkenes. The major enantiomer formed in the reduction of six-membered alkenes could be predicted from a selectivity model and isomeric alkenes had complementary enantioselectivity, giving opposite optical isomers upon hydrogenation. The utility of the reaction was demonstrated by using it as a key step in the preparation of chiral 1,3-cis-cyclohexane carboxylates.
authors.affiliation: Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576, S-75123, Uppsala, Sweden.
authors.forename: J Johan
authors.initials: JJ
authors.lastname: Verendel
authors.forename: Jia-Qi
authors.initials: JQ
authors.lastname: Li
authors.forename: Xu
authors.initials: X
authors.lastname: Quan
authors.forename: Byron
authors.initials: B
authors.lastname: Peters
authors.forename: Taigang
authors.initials: T
authors.lastname: Zhou
authors.forename: Odd R
authors.initials: OR
authors.lastname: Gautun
authors.forename: Thavendran
authors.initials: T
authors.lastname: Govender
authors.forename: Pher G
authors.initials: PG
authors.lastname: Andersson