Rhodium catalyzed deuteroformylation of styrene: (E)- and (Z)-β-deuterostyrene and Β, β-dideuterostyrene formation via selective β-hydride elimination from the branched alkylrhodium intermediate

Article abstract of DOI:10.1016/S0022-328X(00)99397-5

Deuteroformylation of styrene in the presence of Rh4(CO)12 as a catalytic precursor was carried out at 160 atm of CO and D2 1/1 at two temperatures (20 and 90 deg C) and for times yielding partial or complete conversion.Compounds recovered from the mixture produced by reaction and partial conversion at 90 deg C include unlabeled styrene, (E)- and (Z)-β-deuterostyrene, C6H5CH=CHD, and β,β-dideuterostyrene, C6H5CH=CD2, whereas at room temperature the styrene does not take up deuterium.These results indicate that under hydroformylation conditions the branched alkylrhodium intermediate, which affords the branched aldehyde, in part dissociates into rhodium hydride and deuterated olefin.By contrast the linear alkyl intermediate does not disssociate under the same conditions, but instead yields almost completely the corresponding aldehyde.