Synthesis of Silicon-Stereogenic Silanols Involving Iridium-Catalyzed Enantioselective C–H Silylation Leading to a New Ligand Scaffold
Hongpeng Zhang, Dongbing Zhao
Abstract
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.