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Tetraphenylphosphonium pentakis(pentafluoroethyl)stannate [PPh4][Sn(C2F5)5] a new gas-free C2F5 transfer reagent LiC2F5 represents one of the most simple transfer reagents for the C2F5 group. However, its preparation from gaseous HC2F5 or IC2F5 requires specially designed apparatuses, which obviously limits its scope as a synthetic reagent. The solid, storable and short-term airstable [PPh4][Sn(C2F5)5] overcomes this limitation. Now pentafluoroethylation reactions using [PPh4][Sn(C2F5)5] are effected by the addition of n-butyllithium in diethyl ether at -70 °C and the subsequent addition of suitable electrophiles. The by-product n-Bu4Sn can be removed by sublimation and recrystallization, distillation as well as silica gel column chromatography. Tetraphenylphosphonium pentakis(pentafluoroethyl)stannate; 95% Article No: AB473271 CAS 2206680-59-1 Advantages of [PPh4][Sn(C2F5)5] ■ Gas-free ■ No special apparatuses required ■ Short-term airstable Caution: LiC2F5 is highly reactive and tends to decompose violently at temperatures above -50 °C. Gute Chemie 2 . 7 1 9 0 . 3 7 2 1 9 4 SnC2F5C2F5C2F5C2F5C2F5+ 0.25 [PPh4][Sn(C2F5)5] + n-BuLiOHtBuEt2O, -70 °C - rt, 12 h2. HCl/H2OtBuC2F5OHH61 %
Selected pentafluoroethylation reactions with [PPh4][Sn(C2F5)5]. Substrate Product O H OH H C2F5 tBu tBu O Ph H O Ph Ph Et2N Et2N P Cl Me Me Si Cl Me OH Ph H C2F5 OH Ph Ph C2F5 Et2N Et2N P C2F5 Me Me Si C2F5 Me O OEt OH C2F5 C2F5 Me Me [Sn(C2F5)5]- (equiv.) n-BuLi (equiv.) Separation of n-Bu4Sn Yield (%) 0.25 0.25 0.25 1 1 1 chromato. 61a chromato. 34a sublim. + recrystal. 52a 0.25 1.2 dest. 73a,c 0.17 0.85 -- 91b 0.50 1.90 -- 36b [a] isolated yield; [b] according to the 19F NMR spectrum; [c] no aqueous workup By Wiesemann, Markus; Kloesener, Johannes; Neumann, Beate; Stammler, Hans-Georg; Hoge, Berthold From Chemistry - A European Journal (2018), 24(8), 1838-1843; and Wiesemann, Markus; Hoge, Berthold From Chemistry - A European Journal (2018), DOI:10.1002/chem.201801292. 300.000 specialty chemicals – just one click away: visit the abcr web shop and discover our broad range of services at www.abcr.de Gute Chemie abcr GmbH · Phone +49 721 95061 - 0 · Fax +49 721 95061 - 80 · info@abcr.de · www.abcr.de