Zn/F carbenoids: preparation, structures, stability, and application to nucleophilic monofluoroalkylation

Abstract

Carbenoids have been important reactive intermediates in organic synthesis. Thus, numerous investigations have focused on carbenoids with diverse M/X (M = metal, X = leaving group) combinations. However, there have been limited studies on Zn/F carbenoids, despite their potential as nucleophilic monofluoroalkylating reagents. Here, we present the results of comprehensive studies on Zn/F carbenoids. These carbenoids can be generated at ambient temperature through the oxidative addition of 1-fluoro-1-haloalkanes. At 23 °C, they exhibit a half-life of several hours, which is a more than a 10⁶-fold increase compared to that of Li/F carbenoids. This increased stability facilitated various NMR analyses, which revealed for the first time their solution-state structure and their decomposition mechanism. In the presence of CuCN·2LiCl, Zn/F carbenoids efficiently couple with various electrophiles, demonstrating broad functional group compatibility at ambient temperature and enabling facile access to diverse functionalized monofluoroalkanes.