Atroposelective Silylation of 1,1′‐Biaryl‐2,6‐diols by a Chiral Counteranion Directed Desymmetrization Enhanced by a Subsequent Kinetic Resolution

• Published in: Angewandte Chemie International Edition Vol. 62; no. 27; pp. e202304475 - n/a
• Main Authors: Zhu, Min, Jiang, Hua‐Jie, Sharanov, Illia, Irran, Elisabeth, Oestreich, Martin
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 03-07-2023
• Edition: International ed. in English
• Subjects: Atropisomerism; Desymmetrization; Diols; Enantiomers; Kinetic Resolution; Organocatalysis; Phenols; Silylium Ions; Silylium Ions; Atropisomerism; Kinetic Resolution; Organocatalysis; Desymmetrization
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202304475

A desymmetrizing silylation of aromatic diols is reported. The previously unknown asymmetric silyl ether formation of phenol derivatives is achieved by applying List's counteranion directed silylation technique. A silylium‐ion‐like silicon electrophile generated from an allylic silane paired with an imidodiphosphorimidate (IDPi) enables enantioselective discrimination of achiral 1,1′‐biaryl‐2,6‐diols. The enantioselectivity of that desymmetrization is further improved by a downstream kinetic resolution, converting the monosilylated minor enantiomer into the corresponding, again achiral bissilylated diol.
An enantioselective silylation of biaryl diols is achieved with a silylium‐ion‐like silicon electrophile paired with a List‐type imidodiphosphorimidate (IDPi). The initial enantioinduction of the desymmetrization is further enhanced by a downstream kinetic resolution that kinetically selects the monosilylated minor enantiomer to form the corresponding bissilylated diol (see Scheme; TBS=tert‐butyldimethylsilyl).