121598-57-0Relevant articles and documents
Palladium-catalyzed asymmetric reduction of racemic allylic esters with formic acid: Effects of phosphine ligands on isomerization of π- allylpalladium intermediates and enantioselectivity
Kawatsura, Motoi,Uozumi, Yasuhiro,Ogasawara, Masamichi,Hayashi, Tamio
, p. 2247 - 2257 (2007/10/03)
A new MOP ligand (lb), (R)-(+)-2-(bis(3- trifluoromethylphenyl)phosphino)-2'-methoxy-1,1'-binaphthyl, was found to be more enantioselective than other MOP ligands for the palladium-catalyzed asymmetric reduction of α,α-disubstituted allylic esters with formic acid. The reduction of DL-2-(1-naphthyl)-3-buten-2-yl benzoate gave 3-(1-naphthyl)- 1-butene of 90% ee. The higher enantioselectivity of lb is ascribed to fast syn-anti isomerization of π-allylpalladium intermediates formed by oxidative addition of allylic ester to a palladium(0) species. The rate of syn-anti isomerization was measured by the magnetization saturation transfer in 1H NMR. (C) 2000 Elsevier Science Ltd.