Recent Advances in the Synthesis of CF<sub>3</sub>‐ or HCF<sub>2</sub>‐Substituted Cyclopropanes
Wenfeng Wu, Jin‐Hong Lin, Ji‐Chang Xiao, Yucai Cao, Yanfang Ma
Abstract
Abstract CF 3 ‐ or HCF 2 ‐substituted cyclopropanes are of great interest in pharmaceutical chemistry and agrochemistry, and thus significant efforts have been directed towards the development of efficient methods for the installation of these motifs. This Minireview summarizes recent efforts for the construction of CF 3 ‐ or HCF 2 ‐substituted cyclopropanes. CF 3 ‐cyclopropanes are usually synthesized by a transition‐metal‐catalyzed cyclopropanation of alkenes with a trifluoromethylcarbene generated in situ from a diazocompound, CF 3 CHN 2 or CF 3 C(Ar)N 2 . The synthesis of HCF 2 ‐cyclopropanes remains largely unexplored. Some difluoromethylcarbene reagents have been developed, such as HCF 2 CHN 2 , Ph 2 S + CH 2 CF 2 H TfO − , and difluoroacetaldehyde N ‐triftosylhydrazone (DFHZ‐Tfs), and cyclopropanation of alkenes with these reagents could also occur by transition metal catalysis. These protocols may find great utility in the synthesis of biologically active molecules.