title: A new family of cinchona-derived bifunctional asymmetric phase-transfer catalysts: application to the enantio- and diastereoselective nitro-Mannich reaction of amidosulfones.
abstract: A new family of bifunctional H-bond donor phase-transfer catalysts derived from cinchona alkaloids has been developed and evaluated in the enantio- and diastereoselective nitro-Mannich reaction of in situ generated N-Boc-protected imines of aliphatic, aromatic, and heteroaromatic aldehydes. Under optimal conditions, good reactivity and high diastereoselectivities (up to 24:1 dr) and enantioselectivities (up to 95% ee) were obtained using a 9-amino-9-deoxyepiquinidine-derived phase-transfer catalyst possessing a 3,5-bis(trifluoromethyl)phenylurea H-bond donor group at the 9-position.
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford , Mansfield Road, Oxford OX1 3TA, U.K.
authors.forename: Kayli M
authors.initials: KM
authors.lastname: Johnson
authors.forename: Matt S
authors.initials: MS
authors.lastname: Rattley
authors.forename: Filippo
authors.initials: F
authors.lastname: Sladojevich
authors.forename: David M
authors.initials: DM
authors.lastname: Barber
authors.forename: Marta G
authors.initials: MG
authors.lastname: Nuñez
authors.forename: Anna M
authors.initials: AM
authors.lastname: Goldys
authors.forename: Darren J
authors.initials: DJ
authors.lastname: Dixon