The π-(Hydroxyalkenyl)germane Complexes Rh(acac){η2-(E)-Et3GeCHCHC(OH)R2}(PCy3) (R = Me, Ph) as Intermediates in the Hydrogermylation of Alkynols Catalyzed by Rh(acac)(cyclooctene)(PCy3)
摘要:
The (hydroxyalkenyl)germanes (E)-R3GeCH=CHC(OH)R'(2) (R = Et, Ph; R' = Me, Ph) are prepared in quantitative yield, and in a catalytic manner, by addition of germanes to the alkynols HC=CC(OH)R'(2) (R' = Me, Ph) in the presence of the complex: Rh(acac)(cyclooctene)(PCy3). During the reactions four cycles are evident. They have as a common point the intermediates Rh(acac){eta(2)-(E)-CH(GeR3)=CHC(OH)R'(2)}(PCy3), which have been isolated for R = Et and R' = Me, Ph.