Ph₂SCCO: A New Versatile CCO-Fragment Transfer Reagent

Area of Science:

• Organic Chemistry
• Synthetic Methodology
• Small Molecule Reactivity

Background:

• Ketenylidene (C2O) is a small molecule with potential as a C2 synthon.
• Its high reactivity limits practical applications in organic synthesis.

Purpose of the Study:

• To develop a stable and controllable reagent for C2O transfer.
• To explore the synthetic utility of this new reagent in organic transformations.

Main Methods:

• Synthesis of the heterocumulene Ph2S═C═C═O (1).
• Investigation of its reactivity profile, including reactions with Brønsted acids.
• Exploitation of the resulting sulfur ylide intermediate for subsequent reactions.

Main Results:

• The heterocumulene (1) acts as a well-defined C2O equivalent.
• It exhibits integrated ketene-like and carbene reactivity.
• Controlled CCO fragment transfer was achieved, enabling synthesis of cyclopropanation and epoxidation products.

Conclusions:

• Ph2S═C═C═O (1) offers a practical solution for utilizing C2O reactivity in synthesis.
• This reagent facilitates efficient access to valuable α-cyclopropyl and α-epoxy carbonyl compounds.
• The developed strategy allows for the construction of complex bicyclic cyclopropanes.