First examples of improved catalytic asymmetric C-C bond formation using the monodentate ligand combination approach.
[reaction: see text] Using a combination of chiral monodentate phosphoramidite ligands in the rhodium-catalyzed conjugate addition of boronic acids to three different substrates, we have shown for the first time that the ligand combination approach is applicable for C-C bond formation. Chiral catalysts based on hetero-combinations of ligands are found to be more effective than the homo-combinations. (31)P NMR experiments show that the hetero-combinations are formed in excess over the homo-combinations.
Duursma
Ate
A
Department of Organic and Molecular Inorganic Chemistry, Stratingh Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Hoen
Rob
R
Schuppan
Julia
J
Hulst
Ron
R
Minnaard
Adriaan J
AJ
Feringa
Ben L
BL