Asymmetric 1,4-addition of phenylboronic acid to 2-cyclohexenone catalyzed by Rh(I)/binap complexes.
Reaction of 2-cyclohexenone with phenylboronic acid in the presence of 3 mol% of a rhodium(I)/(S)-binap catalyst in dioxane/H2O (10/1) at 100 degrees C proceeded with high enantioselectivity to give a high yield of (S)-3-phenylcyclohexanone of up to 99% ee. The high enantioselectivity was achieved by use of a catalyst generated in situ from Rh(acac)(C2H4)2 and (S)-binap or Rh(acac)((S)-binap) as an isolated rhodium-phosphine complex.
Takaya
Y
Y
Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan.
Ogasawara
M
M
Hayashi
T
T