Indenyl-ruthenium

Fig. 6 Indenyl-ruthenium(II) complexes containing chiral allenylidene chains...

Moreover, taking advantage of the regioselectivity shown by the indenyl-ruthenium(II) complexes [Ru(77 -C9H7)(=C=C=CR R )(PPh3)2][PF6], an efficient... 

Fig. 17 Indenyl-ruthenium(II) tr-alkynyl complexes generated from allenylidenes...

Otherwise, the reactions of indenyl-ruthenium(II) allenylidenes [RuCty -CgHy) =C=C=C(R )Ph (PPh3)2][PF6] (R = H, Ph) with ynamines R C CNEtj (R = Me, SiMea) have been reported to yield the alkenyl(amino)allenylidene complexes 41 via insertion of the ynamine into the Cp=Cy allenylidene bond (Scheme 10) [52, 53], This insertion process involves an initial nucleophilic addition of the ynamine at Cy atom of the cumulene, which leads to the cationic alkynyl intermediate complexes 39. Further ring closing, involving the Cp atom, generates the [2+2]... 

We reported the use of an indenyl ruthenium complex 2 as a racemization catalyst which did not produce ketones as the byproducts [17]. The metal catalyst requires a weak base like triethylamine and molecular oxygen to be activated. The DKR with 2 in combination with an immobilized PCL was carried out at a lower temperature (60°C) to afford good yields and high optical purities (Scheme 1.15). It is noteworthy that 2 does not require ketone as hydrogen mediator for racemization. 

Unlike the chromium and tungsten allenylidenes 46, the coupling of the indenyl-ruthenium(II) allenylidene SO with ynamine MeC=CNEt2 takes place regioselectively... 

In 1999, Park s group showed that the indenyl ruthenium complex, depicted in Scheme 4.5, could be applied to the DKR of 1-phenylethanol with Pseudomonas cepacia lipase (PCL) in the presence of molecular oxygen and TEA, without the presence of hydrogen mediators. Both excellent yield and enan-tioselectivity were obtained by using p-chlorophenyl acetate as the acyl donor, as shown in Scheme 4.5. 

Scheme 4.5 DKR of 1 -phenylethanol with an indenyl ruthenium catalyst.

Protonation reactions of indenyl-ruthenium(ll) monohydrides [RuH( -C9H7)(L )(L )] with triflic or tetrafluoro-boric acid have been explored at —60°C, the nature of the resulting products being also strongly dependent on the... 

Ph=GH2)Gp (PEt3)2][BPh4] and [OsH(G=GGPh=GH2)Gp(PPp3)2][PF6] are also known. They have been obtained by dehydration of the methyl-substituted 3-hydroxyalkynyl ligand in complexes [RuH G=GG(OH)-MePh Cp (PEt3)2][BPh4] and [OsH feCC(OH)MePh Cp(PPr 3)2][PF6], respectively.Deprotonation of the optically active indenyl-ruthenium(ii) allenylidene 138 with KOBu to yield 139 has also been reported (see Equation (9)). 

Indenyl-ruthenium(ii) oxa-cyclocarbene derivatives 160 have been prepared by selective protonation of the alkenyl unit in complexes 159 (Equation Following a similar synthetic approach, the cyclopentadienyl... 

The iron species [Fe(X)2 CN(PP)CH(Me) = CH(Me)N(Pr ) ] (X = Cl, Br), containing highly donating imidazolyidene ligands, have been found to be extremely active and efficient catalysts for the atom transfer radical polymerisation of styrene and methylmethacrylate. A variety of indenyl ruthenium complexes containing either phenylacetylide (C = CPh) or vinyl (CH = CHPh) ligands have been found to catalyse the dimerisation of phenylacetylene to ( )-and (Z)-l,4-diphenyl-l-en-3-yne with the activity of the catalyst dependent upon the nature of the phosphine co-ligand bound to ruthenium. The vinylidene-ruthenium(II) complexes [Ru(Cl)(L)2(C = CHR)] (R = Bu, ferrocenyl L =... 

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