Phosphazene Base Mediated (sp³)CH Functionalization with CO₂ and CS₂

This is the authors' abstract. We don't add key points for this paper.

The activation of weakly acidic (sp 3 )CH bonds in substrates such as fluoroform (HCF 3 ), perfluoroethane (HC 2 F 5 ), and acetonitrile (H 3 CCN) remains a fundamental challenge in synthetic chemistry. We report that the phosphazene base {(Et 2 N) 3 P=N} 3 P=N t Bu (EtP 4 ) enables the selective deprotonation of these molecules when combined with electrophilic small molecules such as CO 2 or CS 2 . This cooperative approach affords a variety of structurally diverse anions, including CF 3 ‐substituted dithiocarboxylates and novel five‐ and six‐membered cyano‐thiolato‐dithioheterocycles resulting from activation of H 3 CCN. The ring compounds are stable in air and are characterized by single‐crystal X‐ray diffraction, infrared spectroscopy, and mass spectrometry. These findings expand the scope of metal‐free base/electrophile systems for (sp 3 )CH functionalization and provide synthetic access to isolable carbanions derived from otherwise inert substrates.