Synthesis of Silicon-Stereogenic Silanols Involving Iridium-Catalyzed Enantioselective C–H Silylation Leading to a New Ligand Scaffold

Despite a growing focus on the construction
of highly enantioenriched
silicon-stereogenic organosilicon compounds, the enantioselective
synthesis of silicon-stereogenic silanols through asymmetric catalysis
remains a considerable challenge. Herein, we realized enantioselective
construction of silicon-stereogenic diarylsilanols via an Ir-catalyzed
C–H silylation of diarylsilanols along with stereospecific
substitution or Tamao–Fleming oxidation. This strategy gives
rise to a class of chiral diol catalyst cores (PSiOLs). Transformation
of PSiOLs led to the ligand possessing both Si and P-stereocenters,
which is capable of inducing excellent enantioselectivity in the rhodium­(I)-catalyzed
conjugate 1,4-addition of aryl boronic acids to cyclohexenone.