title: Chiral organic contact ion pairs in metal-free catalytic asymmetric allylic substitutions.
abstract: Chiral contact ion-pair catalysis with particular focus on metal-free processes is gaining in interest. As a result, new perspectives are opened, and highly stereoselective transformations, traditionally performed under metal catalysis, can be realized. Herein, we report the development of an unprecedented asymmetric Brønsted acid-catalyzed allylic alkylation. The concept relies on chiral contact ion-pair catalysis, in which the chiral organic counteranion of an allylic carbocation induces high enantioselectivities and allows access to biologically relevant chromenes in good yields and with excellent enantioselection.
authors.affiliation: Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany. Magnus.Rueping@rwth-aachen.de
authors.forename: Magnus
authors.initials: M
authors.lastname: Rueping
authors.forename: Uxue
authors.initials: U
authors.lastname: Uria
authors.forename: Ming-Yuan
authors.initials: MY
authors.lastname: Lin
authors.forename: Iuliana
authors.initials: I
authors.lastname: Atodiresei