Asymmetric hydroformylation of vinyl arenes catalyzed by furanoside diphosphinites-Rh(I) complexes

Diphosphinite ligands 2 and 3, easily prepared from inexpensive d(+)-xylose in few steps, were tested in the Rh-catalyzed asymmetric hydroformylation of several vinyl arenes. High regio-selectivities in branched aldehyde (up to 99%) and moderate enantio-selectivity (up to 63%) were found (20-40 °C, 30-60 bar of syn gas). For the first time, the structure in solution of the species formed under hydroformylation conditions with diphosphinite ligands was determined.