Supported heteropolyanions as solid counterions for the electrostatic immobilization of chiral copper complexes

R. TORVISO; M. BLANCO; CACERES, C; J.M. FRAILE; J.A. MAYORAL

JOURNAL OF CATALYSIS

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam-Holanda; Año: 2010 vol. 275 p. 70 - 77

0021-9517

Supported (PW12O40H3 ) is a suitable counterion to immobilize chiral azabis(oxazoline)–copper complexesthrough electrostatic interactions (ion pair formation). Catalytic results are good to excellent incyclopropanation reactions (up to 97% ee). Partial leaching during recycling when mono-exchangedspecies are present, favored by strong coordination of by-products, can be minimized by a proper solventchoice and by optimization of the recycling system, allowing the recovery and reuse of the catalyst atleast six times without loss of activity and enantioselectivities in the range of 82–96% ee for transcyclopropanes.