Modular solid-phase synthesis, catalytic application and efficient recycling of supported phosphine-phosphite ligand libraries.
In spite of decades of research in the field of homogeneous asymmetric catalysis the discovery of new high performance catalysts still relies heavily on trial-and-error. There is still a lack of efficient combinatorial methods which enable the synthesis and screening of vast ligand libraries, especially for bidentate phosphorus ligands. Here we present a highly modular solid-phase synthetic approach which provides facile access to libraries of phosphine-phosphite ligands in quantitative yield requiring only minimal work-up. The obtained library of supported phosphine-phosphites was successfully applied in rhodium catalyzed asymmetric hydrogenation obtaining high enantioselectivities up to 98%. Also, these polymer supported ligands could be successfully recycled under batch conditions exhibiting only a small decline of activity and no loss of selectivity.
EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK. pcjk@st-andrews.ac.uk.
Frank J L
FJ
Heutz
Paul C J
PC
Kamer