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Filyakova,T.I. et al.

, (1979)

-

Chambers,Palmer

, p. 4217,4223 (1969)

Reactions of half-sandwich ethene complexes of rhodium(I) toward iodoperfluorocarbons: Perfluoro-alkylation or -arylation of coordinated ethene versus oxidative addition

Gil-Rubio, Juan,Guerrero-Leal, Juan,Blaya, Maria,Vicente, Jose,Bautista, Delia,Jones, Peter G.

experimental part, p. 1287 - 1299 (2012/04/10)

Perfluoroalkylation or perfluoroarylation of coordinated ethene takes place when complexes [Rh(η5-Cp*)(η2-C 2H4)2] or [Rh(η5-Cp*) (η2-C2H4)(PR3)] react with IRF, to give complexes [Rh(η5-Cp*)(CH 2CH2RF)(μ-I)]2 (RF = CF(CF3)2(1a), CF(CF3)CF2CF 3 (1b), or C(CF3)3 (1c)) and [(η5-Cp*)IRh(μ-I)2Rh(η5- Cp*)(CH2CH2RF)] (2a-c), or [Rh(η5-Cp*)(CH2CH2R F)I(PR3)] (R = Me, RF = CF(CF3) 2 (3a), C(CF3)3 (3c), C6F 5 (3d); R = Ph, RF = CF(CF3)2 (3a′), CF2C6F5 (3e′)), respectively. Bridge splitting reactions of 1a, 1b, or 1c with phosphines afford complexes [Rh(η5-Cp*)(CH2CH2R F)I(PR3)] (3a, 3a′, 3c; RF = CF(CF 3)2, R = iPr (3a″); RF = CF(CF3)CF2CF3, R = Me (3b), Ph (3b′)). In contrast, oxidative addition dominates over addition to ethene in the reactions of [Rh(η5-Cp*)(η2-C2H 4)(PMe3)] with IRF (RF = CF 2C6F5, nC3F7, nC4F9, CF=CF2) and in the reaction of [Rh(η5-Cp)(η2-C2H 4)(PMe3)] with InC4F9, affording complexes of the type [Rh(η5-C5R 5)(RF)I(PMe3)] (4e-h and 5, respectively). The reaction of [Rh(η5-Cp*)(η2-C 2H4)(PR3)] with ICF(CF3)CF 2CF3 gives a mixture of cis- and trans-octafluoro-2-butene as the main fluoroorganic reaction product. Evidence for the intermediacy of RF- anions in these reactions has been obtained. 3a′ reacts with AgOTf (OTf = O3SCF3) and XyNC or CO to give complexes [Rh(η5-Cp*){CH2CH 2CF(CF3)2}(CNXy)(PPh3)]OTf (6) or [Rh(η5-Cp*){C(O)CH2CH2CF(CF 3)2}(CO)(PPh3)]OTf (7), respectively. Complex [Rh(η5-Cp*)I(py)(PMe3)]BF4 (8) was obtained either by reaction of (1) [Rh(η5-Cp*) (η2-C2H4)(PMe3)] with [I(py)2]BF4 or (2) [Rh(η5-Cp*)I 2(PMe3)] with AgBF4 and py. The crystal structures of 1a, 1b, 3c, 4g, 7, and 8 have been determined.

Solvents for use in fluorination reactions

-

, (2008/06/13)

A method of fluorinating an organic compound comprising reacting an organic compound with a fluorinating agent characterized in that a perfluorocarbon compound is present in the reaction medium. The perfluorocarbon compound may replace an amount of a solvent which would otherwise be required for the reaction to proceed efficiently. The perfluorocarbon compound is readily recoverable after reaction and may be re-used in subsequent reactions. Additives to the reaction medium, such as 18-crown-6, may increase the amoun of solvent which may be replaced. The method is beneficial where solvent consumption would otherwise be large, or where solvent recovery would otherwise be difficult.