Enantioselective catalysis based on palladium enolate chemistry

INOR 8

Mikiko Sodeoka, sodeoka@riken.jp, Synthetic Organic Chemistry Lab, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
We have found that chiral Pd aqua complexes [Pd(ligand)(H2O) 2]X2 and binuclear Pd µ-hydroxo complexes [Pd(ligand)(OH)] 2X2 (ligand = BINAP or SEGPHOS derivatives) work as mild Brønsted acid and base catalyst. By using these complexes the chiral Pd enolates were generated from the carbonyl compounds and reacted with various electrophiles activated by a proton under acidic conditions. Highly enantioselective Michael addition, Mannich-type reaction, aldol reaction, and fluorination, have been achieved. Pd-catalyzed addition of amines or hydride to α, β-unsaturated carbonyl compounds generating Pd enolates was also found to proceed enantioselectively.