156088-38-9Relevant articles and documents
Synthesis and properties of trifluoromethylated stannanes. The formation and NMR spectra of the difluoromethylstannanes (CF3)n(CF2H)mSn(CH3)4-n-m
Eujen, R.,Jahn, N.,Thurmann, U.
, p. 153 - 160 (2007/10/02)
Difluoromethylstannanes have been obtained by hydrogenation of (CF3)4Sn with the hydrides (CH3)3MH (M=Sn, Ge).The reaction is shown to proceed via attack of the hydride on the tin atom; transfer of fluoride from the CF3 group to the MMe3 group along with elimination of CF2 yields the unstable (CF3)3SnH.Difluorocarbene is inserted quantitatively into Sn-H bonds, thus forming both Me3SnCF2H and (CF3)3SnCF2H.The latter is subject to further formal replacements of CF3 by CF2H groups, finally yielding Sn(CF2H)4.For M=Sn, further methyl/trifluoromethyl exchanges lead to a variety of methyl-containing species, (CF3)n(CF2H)mSnMe4-n-m.For M=Ge, insertion of CF2 into the Ge-H bond is not observed; the lower reactivity of GeMe3H towards CF2 is demonstrated independently by its reaction with such CF2 sources as CF3SiF3 and CF2Br2/C2(NMe2)4; trimethylgermyltin derivatives, (CF3)n(CF2H)mSnGeMe3, are formed, with evolution of CF2H2.The compounds have been identified by their characteristic NMR spectra.Owing to Lewis acid/base interactions NMR chemical shifts and coupling constants are very sensitive to the choice of solvent.Linear correlations between the 2J(SnF) couplings of CF3 and CF2H groups and between 1J(SnC) and 2J(SnF) are found. Key words: Tin; Difluoromethyl; Group 14; Fluorine
