# Enantioconvergent Synthesis of Diarylmethane Drugs via Privileged Benzhydrol Intermediates

**Authors:** Eduard Frank, Jana L. Flügel, Ludwig d’Heureuse, Sophie Woick, Alexander Breder

PMC · DOI: 10.1021/acs.joc.5c02530 · 2025-12-26

## TL;DR

A new method for making chiral benzhydrol intermediates is developed, enabling efficient synthesis of diarylmethane drugs.

## Contribution

An enantioconvergent synthesis of benzhydrols via asymmetric migratory Tsuji-Wacker oxidation is introduced.

## Key findings

- Chiral α,α-diaryl ketones are obtained with up to 91% ee via asymmetric oxidation.
- The method allows for the synthesis of (S)-cloperastine and isotopically labeled (S)-diphenhydramine-d5.
- Benzhydrols are established as versatile intermediates for drug assembly.

## Abstract

The benzhydryl motif is a privileged pharmacophore in
antihistaminic
and neuroactive drugs. We present a broadly applicable, enantioconvergent
synthesis of benzhydrols via asymmetric migratory Tsuji-Wacker oxidation
of stilbenes. This constitutionally stereodivergent protocol operates
without preactivated or sterically biased substrates, affording chiral
α,α-diaryl ketones in up to 91% ee, which
convert to benzhydrols without erosion of stereochemistry. The method
enables concise syntheses of (S)-cloperastine and
isotopically labeled (S)-diphenhydramine-d
5, establishing chiral benzhydrols as versatile
intermediates for redox- and step-economic drug assembly.

## Linked entities

- **Chemicals:** cloperastine (PubChem CID 2805)

## Full-text entities

- **Chemicals:** stilbenes (MESH:D013267), (S)-cloperastine (MESH:C040282), benzhydrols (MESH:C020225), (S)-diphenhydramine-d5 (-)

## Figures

5 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12797289/full.md

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Source: https://tomesphere.com/paper/PMC12797289