Phosphinomethylation of [1 ′-(diphenylphosphino)ferrocenyl]-methylamines as a route to unsymmetric ferrocene diphosphine ligands

Publication date: 15 January 2018 Source:Journal of Organometallic Chemistry, Volume 855 Author(s): Ondřej Bárta, Ivana Císařová, Petr Štěpnička [1′-(Diphenylphosphino)ferrocenyl]methylamine (1) reacts with Ph2PH/(CH2O)x or [Ph2P(CH2OH)2]Cl to give mixtures of Ph2PfcCH2NHCH2PPh2 and Ph2PfcCH2N(CH2PPh2)2 in which the triphosphine dominates (fc = ferrocene-1,1′-diyl). To avoid unwanted two-fold phosphinomethylation, the amine group in 1 was alkylated. As expected, the reaction of the N-methyl analogue Ph2PfcCH2NHMe (5), obtained by reductive methylation of the aldehyde Ph2PfcCHO, with [Ph2P(CH2OH)2]Cl, only led to the diphosphine Ph2PfcCH2N(Me)CH2PPh2 (6). The diphosphine was structurally characterized and further reacted with [PdCl2(MeCN)2] and [PdCl(Me)(cod)] (cod = η2:η2-cycloocta-1,5-diene), affording the respective trans-chelate complexes [PdCl(X){Ph2PfcCH2N(Me)CH2PPh2-κ2 P,P′}] (7a: X = Cl; 7b: X = Me), which were also structurally authenticated by X-ray diffraction analysis. Graphical abstract

Source: Journal of Organometallic Chemistry - December 16, 2017 Category: Chemistry Source Type: research