Pd(OAc)<sub>2</sub>/P(<i><sup>c</sup></i><sup></sup>C<sub>6</sub>H<sub>11</sub>)<sub>3</sub>-Catalyzed Allylation of Aryl Halides with
Homoallyl Alcohols via Retro-Allylation
Masayuki Iwasaki
Sayuri Hayashi
Koji Hirano
Hideki Yorimitsu
Koichiro Oshima
10.1021/ja067372d.s001
https://acs.figshare.com/articles/journal_contribution/Pd_OAc_sub_2_sub_P_i_sup_c_sup_i_sup_sup_C_sub_6_sub_H_sub_11_sub_sub_3_sub_Catalyzed_Allylation_of_Aryl_Halides_with_Homoallyl_Alcohols_via_Retro_Allylation/3013549
Allylations of aryl halides take place upon treatment of tertiary homoallyl alcohols with aryl halides
in the presence of cesium carbonate and a palladium catalyst. The allylation reaction would consist of the
following steps: (1) oxidative addition of aryl halide to palladium, (2) ligand exchange between the halide
and the homoallyl alcohol affording aryl(homoallyloxy)palladium, (3) retro-allylation of the palladium alkoxide
to generate σ-allyl(aryl)palladium with concomitant liberation of the relevant ketone, and (4) productive
reductive elimination. Since the retro-allylation step proceeds in a concerted fashion via a conformationally
regulated six-membered cyclic transition state, the allylation reactions are highly regio- and stereospecific
when homoallyl alcohols having a substituted allyl group are used. Whereas triarylphosphine is known to
serve as a ligand for the palladium-catalyzed allyl transfer reactions, tricyclohexylphosphine proves to
significantly expand the scopes of aryl halides to electron-rich aryl chlorides and of homoallyl alcohols to
cyclic homoallyl alcohols. The new arylative ring-opening reactions of cyclic homoallyl alcohols allow for
the synthesis of ketones having a branched or linear allylarene moiety at the remote terminus in regio- and
stereospecific manners.
2007-04-11 00:00:00
aryl halides
cyclic homoallyl alcohols
palladium
homoallyl alcohols