Synthesis of a New Multidentate Phosphane Ligand C6H2(CH2PPh2)4-1,2,4,5 − X-ray Structure of a Dinuclear Ruthenium(II)-Bridged Complex: [{RuCl2(PPh3)}2{C6H2(CH2PPh2)4-1,2,4,5-P,P′,P′′,P′′′}]

Abstract

The tetrakis(phosphane oxide) C6H2{CH2P(O)Ph2}4‐1,2,4,5 (5), has been prepared in high yield from the Arbuzov reaction of C6H2(CH2Br)4‐1,2,4,5 (4), with excess (7 equiv.) of Ph2POEt. Subsequent reduction of 5 with HSiCl3 (12 equiv.) in C6H4Cl2‐1,2 afforded the new tetraphosphane C6H2(CH2PPh2)4‐1,2,4,5 (6), in high yield. The reaction of 6 with [RuCl2(PPh3)4] in CH2Cl2 afforded the green dinuclear ruthenium(II) coordination complex [{RuCl2(PPh3)}2{C6H2‐ (CH2PPh2)4‐1,2,4,5‐P,P′,P′′,P′′′}]·0.5 CH2Cl2 (8), in 39% isolated yield. The solid‐state molecular geometry of 8, determined by X‐ray analysis, shows that the tetraphosphane is ortho‐P,P′‐chelated to each of the two [RuIICl2(PPh3)] units.

Hexaphosphine: A Multifaceted Ligand for Transition Metal Coordination

“…[1] As steric effects are crucial in the reactivity of metal-phosphane complexes, a good knowledge of the molecular structures of the species is required both in the solid state and in solution. [6][7][8][9][10][11][12][13][14][15][16][17][18] The performance of some of these branched polyphosphanes in catalysis, for instance, regarding C-C bond formation, [19,20] has driven progress in their synthesis. [6][7][8][9][10][11][12][13][14][15][16][17][18] The performance of some of these branched polyphosphanes in catalysis, for instance, regarding C-C bond formation, [19,20] has driven progress in their synthesis.…”

Molecular‐Weight‐Enlarged Multiple‐Pincer Ligands: Synthesis and Application in Palladium‐Catalyzed Allylic Substitution Reactions

“…The ester groups of 10 were subsequently reduced to hydroxy groups (11), followed by bromination with PBr 3 deriving 3,5-di(bromomethyl)phenol 12. The Arbusov-type quantitative coupling reaction [21] of the diphenylphosphinoxide groups to the benzylic position gave building block 4 in an overall yield of 50 %. This is significantly higher than reported for the above-mentioned method with the bromination step as the only low-yielding step in this sequence.…”

Design of Novel Hexametallic Cartwheel Molecules from Persubstituted Benzene Compounds

“…A modification of a two-step procedure recently reported by us for the synthesis of the tetraphosphane 1,2,4,5-(CH 2 PPh 2 ) 4 C 6 H 2 was used for the synthesis of the dodecaphosphane 5. [8] In the first step, reaction of 2 with Ph 2 POEt in xylenes (Arbuzov reaction conditions) affords the dodeca-(phosphane oxide) 4, in 87 % yield. In the second step 4 is reduced with HSiCl 3 to the corresponding dodecaphosphane 5, which can be obtained in good yield as a white air-sensitive solid.…”

“…To show the potential of 3 ± 6 to function as multiligand precursors for transition metal ions we have examined the direct electrophilic palladation of dodecasulfide 6 with excess [Pd(NCMe) 4 ](BF 4 ) 2 in refluxing MeCN (Scheme 1, reaction e). This reaction yields the ionic complex [C 6 {3,5-(CH 2 SPh) 2 C 6 H 2 [Pd(NCMe)]} 6 ](BF 4 ) 6 (8), in 90 % yield as a pale-yellow solid. Complex 8 is readily converted, by addition of excess Bu 4 NCl in MeCN, into the neutral hexapalladium(ii) complex [C 6 {3,5-(CH 2 SPh) 2 C 6 H 2 (PdCl)} 6 ] (7), which was isolated in quantitative yield as a yellow solid.…”