New synthetic strategy to create intricate thiaoxacyclophanes via ring‐closing metathesis

Abstract

AbstractThis study explores a thiol‐free, two‐step synthetic strategy to intricate thiacyclophanes from bromoaryl precursors. Our methodology involves a one‐pot substitution reaction of aryl bromides with potassium thioacetate (PTA) followed by ring‐closing metathesis (RCM). Potassium thioacetate is advantageous over other sulfur‐containing reagents like sodium sulfide, sodium hydrosulfide, and sodium hydroxymethylsulfinate (rongalite), etc., as it generates a stable and odorless thioacetate intermediate which allows access to a variety of symmetrical and unsymmetrical sulfides. These sulfides undergo RCM to generate new thiacyclophanes. Applying this methodology, we have created 24 new oxa‐thiacyclophanes and aza‐oxa‐thiacyclophanes containing different aromatic and aliphatic units. The structures and stereochemistry of these cyclophanes are confirmed by NMR data and further supported by single‐crystal X‐ray diffraction data.