On Pentakis(pentafluoroethyl)stannate, [Sn(C 2 F 5 ) 5 ] − , and the Gas‐Free Generation of Pentafluoroethyllithium, LiC 2 F 5

Pentafluoroethyllithium, LiC 2 F 5 , has been established as an efficient and versatile reagent for the transfer of the pentafluoroethyl unit to a number of electrophiles. Here, the stability of this species up to −40 °C is of advantage, particularly in comparison to its smaller congener LiCF 3 . The usual production of LiC 2 F 5 , however, from gaseous HC 2 F 5 or IC 2 F 5 and strong bases requires specially designed apparatuses, which severely impeded its value as a laboratory reagent. In this contribution we communicate an alternative gas‐free and highly efficient protocol for the synthesis of LiC 2 F 5 from the already commercialized stannate salt [PPh 4 ][Sn(C 2 F 5 ) 5 ]. The [Sn(C 2 F 5 ) 5 ] − anion represents not only the first example of a structurally characterized hypervalent pentaalkylstannate but also serves as a precursor for the synthesis of the homoleptic tetrakis(pentafluoroethyl)stannane, Sn(C 2 F 5 ) 4 . The reaction of the latter with n‐ butyllithium provides an insight into the mechanism of LiC 2 F 5 generation.