Kinetic Resolution of Tertiary Propargylic Alcohols by Enantioselective Cu−H‐Catalyzed Si−O Coupling

Matchmaker: The commercially available precatalyst system MesCu/(R,R)‐Ph‐BPE couples Ph₃SiH with the fast‐reacting enantiomer of racemic mixtures of tertiary propargylic alcohols. This non‐enzymatic kinetic resolution provides access to synthetically valuable and versatile enantiomerically enriched tertiary propargylic alcohols and the corresponding silyl ethers (see scheme).

Abstract

A broad range of tertiary propargylic alcohols were kinetically resolved by catalyst‐controlled enantioselective silylation. This non‐enzymatic kinetic resolution is catalyzed by a Cu−H species and makes use of the commercially available precatalyst MesCu/(R,R)‐Ph‐BPE and a simple hydrosilane as the resolving reagent. Both alkyl,aryl‐ as well as dialkyl‐substituted propargylic alcohols participate, and especially high selectivity factors are achieved when the alkyne terminus carries a TIPS group, which also enables facile post‐functionalization in this position (s up to 207).

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