Polythioureas: Main chain chiral polymers in hydride transfer hydrogenation

Article abstract of DOI:10.1002/1099-0690(200011)2000:22<3787::aid-ejoc3787>3.0.co;2-0

Chiral polythioureas have been synthesized and tested in asymmetric hydride transfer reduction of ketones with ruthenium. With polyurea 18, 70% ee was attained for acetophenone reduction; after filtration, it can be reused at least four times without any detectable loss of activity and only a slight decrease in selectivity. Various aryl alkyl ketones were reduced with the same system and up to 84% ee was measured with isopropyl phenyl ketone.