Tunable ligands for asymmetric catalysis: readily available carbohydrate-derived diarylphosphinites induce high selectivity in the hydrovinylation of styrene derivatives.
Only a limited number of ligands have been successfully employed for the Ni-catalyzed asymmetric hydrovinylation reaction. Diarylphosphonites prepared from readily available carbohydrates in conjunction with a highly dissociated counterion ([3,5-(CF3)2-C6H3)4B]- or SbF6-) effect the hydrovinylation of 4-bromostyrene or 4-isobutylstyrene under ambient pressure of ethylene with the best overall selectivities reported to date for these important substrates. In a prototypical synthesis of a 2-arylpropionic acid, 3-(4-bromophenyl)-1-butene (prepared in 98% isolated yield and 89% ee from 4-bromostyrene) has been transformed into (R)-ibuprofen by Ni-catalyzed cross-coupling with i-BuMgBr, ozonolysis, and subsequent oxidation of the resulting aldehyde.
Park
Haengsoon
H
Department of Chemistry, 100 West 18th Avenue, The Ohio State University, Columbus, Ohio 43210, USA.
RajanBabu
T V
TV
D002241:Carbohydrates / Q000737:chemistry*; D002384:Catalysis; D008024:Ligands; D010721:Phosphinic Acids / Q000737:chemistry*; D013343:Styrenes / Q000138:chemical synthesis* / Q000737:chemistry; D014753:Vinyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry
D002241:Carbohydrates; D008024:Ligands; D010721:Phosphinic Acids; D013343:Styrenes; D014753:Vinyl Compounds