title: Enantioselective alkynylation of aldehydes with 1-haloalkynes catalyzed by tethered bis(8-quinolinato) chromium complex.
abstract: The first example of Cr-catalyzed asymmetric alkynylation of aldehydes with 1-iodo- and 1-bromoalkynes was developed. The use of tethered bis(8-quinolinato) chromium catalyst (3 mol %) allowed preparation of enantioenriched propargyl alcohols with good yields and enantioselectivities up to 92% ee. 1-Bromoalkynes can be activated by the introduction of a cobalt porphine co-catalyst, which enables shorter reaction times without any loss of enantiocontrol.
authors.affiliation: Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, United States.
authors.forename: Dmitry L
authors.initials: DL
authors.lastname: Usanov
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamamoto