Modular approach to novel chiral aryl-ferrocenyl phosphines by Suzuki cross-coupling.
Two novel planar chiral and atropisomeric P,N and P,O aryl-ferrocenyl ligand systems have been developed. The strategy is short and involves a new synthetic approach to aryl-ferrocenyl compounds via a Suzuki cross-coupling procedure. The modular design can easily give access to variety of chiral mono- and bidentate ligands. Two simple derivatives of a novel chiral bidenate P,N ligand belonging to the MOPF family have been synthesized and tested in the enantioselective copper-catalyzed addition of diethyl zinc to an enone and a "difficult" diester. Moderate to excellent yields and enantioselectivities up to 58% were obtained using 1 mol % Cu(OTf)(2) and 1.5 mol % chiral ligand.
Jensen
Jakob F
JF
Department of Chemistry, Building 201 and 206, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
Søtofte
Inger
I
Sørensen
Henning O
HO
Johannsen
Mogens
M