Mechanistic Investigations on the Hydrogenation of Alkenes Using Ruthenium(II)-arene Diphosphine Complexes

Abstract

The ruthenium(II) complexes [Ru(η 2 -P-P)(η 6 -p-cymene)Cl]Cl, P-P ) diphenylphosphinomethane (dppm), diphenylphosphinoethane (dppe), or diphenylphosphinopropane (dppp), and the highly water-soluble analogues, [Ru(η 2 -P-P)(η 6 -arene)Cl]Na 3 , P-P ) 1,2-bis(di-4sulfonatophenylphosphino)benzene (dppbts), arene ) p-cymene, benzene, or [2.2]paracyclophane, are efficient catalyst precursors for the hydrogenation of styrene in an aqueous biphase. By the use of high gas pressure NMR techniques and electrospay ionization mass spectrometry, the active species in the hydrogenation have been indirectly identified to be a dihydrogen complex, which also catalyzes H/D isotope exchange. Using the ruthenium(II) dppbts derivatives as precatalysts, evidence is provided for an arene exchange process that takes place during the catalytic hydrogenation of styrene. Together, these results lead to the proposition of a catalytic cycle for the hydrogenation of the CdC double bond of styrene using ruthenium(II)-arene diphosphine complexes.

Ruthenium diphosphine complexes as an efficient hydroamination catalyst

“…1 and 2, respectively. The structures of two complexes are similar to previously reported ruthenium(II) complexes of diphosphines [36][37][38][39]. Single crystal structure of 1 confirmed the four-coordinate geometry with two chlorine ion and cymene ligand which is connected through p-electrons of l 6 -cymene and one phosphor of dppm ligand in the complex.…”

“…The ruthenium-P bond distance is 2.3515 Å comparable with reported bond lengths for a four-coordinate ruthenium complex [37]. The RuCl(1) and RuCl(2) distances in 1 are 2.4063(16) and 2.4177(13) Å , respectively.…”

Synthesis, X-ray crystal structure and cytotoxicity of a new tetranuclear ruthenium arene complex

“…The effect of the compounds on cell viability was determined using the MTT assay [16]. Cells were plated on 96-multiwell plates (H4IIE, Hct116, Huh7 cells: 15.000 / well, A2780 cells:…”

The Synthesis and Characterisation of Bis(phosphane)‐Linked (6‐p‐Cymene)ruthenium(II)–Borane Compounds

“…As part of our continuing investigation of these complexes for catalytic hydrogenation reactions, [7] we have embarked on developing methodologies for the preparation of compounds in which the catalytically active ruthenium fragment is linked to other metal and non-metal moieties. These include functionalisation of the coordinated arene with imidazolium groups or crown ether moieties, [8] and formation of a heterometallic carbene complex.…”