Rhodium‐Catalyzed Dynamic Kinetic Asymmetric Hydrosilylation to Access Silicon‐Stereogenic Center

• Published in: Angewandte Chemie International Edition Vol. 61; no. 51; pp. e202214147 - n/a
• Main Authors: Zeng, Yan, Fang, Xiao‐Jun, Tang, Ren‐He, Xie, Jing‐Yu, Zhang, Feng‐Jiao, Xu, Zheng, Nie, Yi‐Xue, Xu, Li‐Wen
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 19.12.2022; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Asymmetric Catalysis; Asymmetry; Catalysts; Chemistry; Chemistry, Multidisciplinary; Chirality; Chloride ions; Density functional theory; Dynamic Kinetic Resolution; Enantiomers; Hydrosilylation; Ligands; Organosilicon; Organosilicon compounds; Phosphine; Phosphines; Physical Sciences; Rhodium; Science & Technology; Silacycle; Silicon; Silicon-Stereogenic; Substitution reactions; Substrates; Dynamic Kinetic Resolution; PHOSPHORUS; Asymmetric Catalysis; HYDROGENATION; ENANTIOSELECTIVITY; Silacycle; SILANES; CONSTRUCTION; Organosilicon; LIGAND; Silicon-Stereogenic; C-H SILYLATION
• DOI: 10.1002/anie.202214147
• ISSN: 1433-7851; 1521-3773

Strategies on the construction of enantiomerically pure silicon‐stereogenic silanes generally relies on desymmetrization of prochiral and symmetric substrates. However, dynamic kinetic asymmetric transformations of organosilicon compounds have remained underdeveloped and unforeseen owing to a lack of an effective method for deracemization of the static silicon stereocenters. Here we report the first Rh‐catalyzed dynamic kinetic asymmetric intramolecular hydrosilylation (DyKAH) with “silicon‐centered” racemic hydrosilanes that enables the facile preparation of silicon‐stereogenic benzosiloles in good yields and excellent enantioselectivities. The special rhodium catalyst controlled by non‐diastereopure‐type mixed phosphine‐phosphoramidite ligand with axial chirality and multiple stereocenters can induce enantioselectivity efficiently in this novel DyKAH reaction. Density functional theory (DFT) calculations suggest that the amide moiety in chiral ligand plays important role in facilitating the SN2 substitution of chloride ion to realize the chiral inversion of silicon center. An unprecedented (SiMOS‐Phos) ligand‐controlled Rh‐catalyzed hydrosilylation of “silicon‐centered” racemic hydrosilanes was developed for the highly efficient and enantioselective construction of silicon‐stereogenic centers of benzosiloles (up to 96 : 4 er). This achievement was obtained by using an original synthetic strategy involving dynamic kinetic asymmetric transformations.