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Asymmetri
c hydrogenation of unsaturated urea esters with the BIPI Ligands has been examined. Optimization of the P-N ligand stru
cture hasled to the development of
chiral rhodium
catalysts
capable of produ
cing the targets with >99% ee. The
criti
cal phosphine borane S
NAr rea
ctionneeded for ligand synthesis has been optimized to give the addu
cts in high yield at ambient temperature with no ra
cemization. An extremely
con
cise, e
conomi
cal, and s
calable sequen
ce to these important new ligands for
catalysis of asymmetri
c hydrogenation has been developed.