Osmium-Allenylidene Complexes Containing an N-Heterocyclic Carbene Ligand
Autores: Ricardo Castarlenas, Miguel A. Esteruelas, Ralte Lalrempuia, Montserrat Oliván y Enrique Oñate
Ref. revista: Organometallics, 27, 795-798, (2008)
Complex [(η6-p-cymene)OsCl(IPr)]OTf (1) reacts with 1,1-diphenyl-2-propyn-1-ol to afford the hydroxyVinylidene
deriVatiVe [(η6-p-cymene)OsCl{dCdCHC(OH)Ph2}(IPr)]OTf(2), which dehydrates to form [(η6-p-cymene)OsCl(dCd
CdCPh2)(IPr)]OTf (3). Treatment in acetonitrile under reflux of the BF4-salt of 3 with AgBF4 leads to the tetrakis(solVento)
deriVatiVe [Os(dCdCdCPh2)(CH3CN)4(IPr)][BF4]2 (4). At 95 °C, the addition of PiPr3 to an acetonitrile solution of 4
yields the dicationic mixed PiPr3-IPr osmium-allenylidene complex [Os(dCdCdCPh2)(CH3CN)3(IPr)(PiPr3)][BF4]2 (5),
which in 2-propanol and in the presence of NaCl eVolVes into the fiVe-coordinate hydride-alkenylcarbyne [OsHCl(tCCHd
CPh2)(IPr)(PiPr3)][BF4] (6). The X-ray structures of 2, 5, and 6 are also reported.
Complex [(η6-p-cymene)OsCl(IPr)]OTf (1) reacts with 1,1-diphenyl-2-propyn-1-ol to afford the hydroxyVinylidene
deriVatiVe [(η6-p-cymene)OsCl{dCdCHC(OH)Ph2}(IPr)]OTf(2), which dehydrates to form [(η6-p-cymene)OsCl(dCd
CdCPh2)(IPr)]OTf (3). Treatment in acetonitrile under reflux of the BF4-salt of 3 with AgBF4 leads to the tetrakis(solVento)
deriVatiVe [Os(dCdCdCPh2)(CH3CN)4(IPr)][BF4]2 (4). At 95 °C, the addition of PiPr3 to an acetonitrile solution of 4
yields the dicationic mixed PiPr3-IPr osmium-allenylidene complex [Os(dCdCdCPh2)(CH3CN)3(IPr)(PiPr3)][BF4]2 (5),
which in 2-propanol and in the presence of NaCl eVolVes into the fiVe-coordinate hydride-alkenylcarbyne [OsHCl(tCCHd
CPh2)(IPr)(PiPr3)][BF4] (6). The X-ray structures of 2, 5, and 6 are also reported.