When SF5outplays CF3: effects of pentafluorosulfanyl decorated scorpionates on copper

Abstract

Polyfluorinated, electron-withdrawing, and sterically demanding supporting ligands are of significant value in chemistry. Here we report the assembly and use of a bis(pyrazolyl)borate, [Ph2B(3-(SF5)Pz)2]−that combines all such features, and involves underutilized pentafluorosulfanyl substituents. The ethylene and carbonyl chemistry of copper(i) supported by [Ph2B(3-(SF5)Pz)2]−, a comparison to the trifluoromethylated counterparts involving [Ph2B(3-(CF3)Pz)2]−, as well as copper catalyzed cyclopropanation of styrene with ethyl diazoacetate and CF3CHN2are presented. The results from cyclopropanation show that SF5groups dramatically improved the yields and stereoselectivity compared to the CF3