The non-heteroatom-substituted alkynyl carbene CP'(CO)(2)Mn=C(Tol)C CPh (1,Cp' (eta(5)-MeC5H4)) is first shown to react at low temperature with lithium diorganophosphide LiPR2 (R = Ph, Cy) to form an anionic species. Subsequent treatment with CF3SO3H affords the eta(4)-vinylketene complex Cp'(CO)(2)Mn[eta(4)- [R2P(Ph)C=CHC(Tol)=C=O}] (2; 2a: R = Ph (70% yield), 2b: R = Cy (55% yield)) as the major compound, along with trace amounts of the eta(2)-allene complex syn-CP'(CO)(2)Mn[eta 2-{Ph2P(Tol)-C=C=C(Ph)H}] (syn-3a) for R = Ph, or along with the eta(2)-allene complex CP'(CO)(2)Mn[eta(2)-{H(Tol)-C=C=C(Ph)PCY2}] (4b, 26% yield, 1:2 mixture of syn/anti isomers) for R = Cy. On the other hand, subsequent treatment with NH4Claq affords only eta(2)-allene complexes, obtained either as a ca. 1:9 mixture of syn-3a and CP'(CO)(2)Mn[eta(2)-{H(Tol)-C=C=C(Ph)PPh2}] (4a) (75% yield) for R = Ph or as a 1:2 mixture of syn- and anti-4b for R = Cy (74% yield). Combined NMR and single-crystal X-ray diffraction studies (for 2a, anti-4b, and syn-4b) revealed that both type 2 and type 4 species result from a nucleophilic attack of the diorganophosphide onto the remote alkynyl carbon atom in I (C.), whereas type 3 species results from a nucleophilic attack of the carbene carbon atom (C.). Complexes 3a and 4a,b are prone to undergo a thermal rearrangement to give the eta'-phosphinoallene complexes CP'(CO)(2)Mn{Ph2P(Tol)C Ph2P(Tol)C=C=C(Ph)H}] (5a) and CP'(CO)(2)Mn[eta(1)-{R2P(Ph)C=C=C(Tol)H}] (6; 6a: R = Ph, 6b: R = Cy), respectively. Reaction of I with p-toluenethiol in the presence of NEt3 (20%) affords a 1. 8: 1 mixture Of CP'(CO)(2)Mn[eta(2)-{TolS(Tol)C=C=C(Ph)H}] (syn-11), resulting from a nucleophilic attack at C-alpha in 1, and CP'(CO)(2)Mn[eta(2)-{H(Tol)C=C=C(Ph)STol}] (12), resulting from a nucleophilic attack at Cy, whereas treatment of I with lithium p-toluenethiolate at -80 degrees C followed by protonation with NH4Claq, gave the same syn-11 and 12 complexes now in a 1:2.3 ratio. Finally, 1 was found to react with cyclohexanone lithium enolate to afford, upon protonation, the eta(2)-allene complex CP'(CO)(2)Mn[eta(2)- {H(Tol)C=C=C(Ph)CH(CH2)(4)C(O)}] (syn-13), resulting from anucleophilic attackat C-gamma in 1. The solidstate structures of syn-11 and syn-13 are also reported.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The present paper deals with the synthesis and full characterization of a series of pyridine-functionalized phosphine complexes of Ru(II), namely, RuCl2(L-nx) (PPh3) (L-nx = R2PCH2(C5H2R'R '' N)), differing in the nature of the substituents on the phosphorus (superscript label n in L-nx defined as n = 1 for R = Ph, n = 2 for R = Cy) and/or on the pyridyl group (superscript label x in L-nx defined as x = a for picolyl, noted pic, and x = b for quinolyl, noted quin) and discloses new aspects of their reactivity with respect to catalysis. The ligands 2-[(diphenylphosphino)methyl]-6-methylpyridine, L-1a, 2-[(diphenylphosphino) methyl]quinoline, L-1b, 2-[(dicyclohexylphosphino)methyl]-6-methylpyridine, L-2a, and 2-[(dicyclohexy- lphosphino)methyl]quinoline, L, were prepared and respectively reacted with RuCl2(PPh3)(3) under optimized experimental conditions. In a preliminary test, the reaction of RuCl2(PPh3)(3) with L-1a using a stoichiometric 1/1 metal/ligand ratio gave three complexes, namely, [RuCl2(PPh3)(2)](2) (1), [(PPh3)(2)ClRu(mu-Cl)(3)Ru(L-1a)(PPh3)] (2(1a)), and RuCl2(L-1a)(2) (3(1a)). These were isolated by fractional crystallization and, at that stage, identified only by single-crystal X-ray diffraction. The formation of 1 and 21a reflects the existence of the elusive 14 e(-) fragment "RuCl2(PPh3)(2)", which tends to relieve its unsaturation by intermolecular association. By contrast, controlled addition of 2-(phosphinomethyl)pyridine type ligands L n, to RuCl2(PPh3)(2) leads selectively to the desired 16 e(-) species RuCl2(L-nx)(PPh3) (4(nx)). For example, with Lu-1b, the green complex RuCl2(L-1b)(PPh3) (4(1b)-trans-Cl) was identified as the kinetic product of ligand addition. It slowly and irreversibly converts into the more stable isomer RuCl2(L-1b)(PPh3) (4(1b)-cis-Cl), representing the thermodynamic product. Both isomers were fully characterized by NMR spectroscopy and X-ray diffraction. Similar transformations, taking place at different rates, were observed within the ligand series examined here. All isomeric forms of type 4(na) complexes react cleanly with a terminal alkyne-like phenylacetylene to give a new complex identified by NMR spectroscopy as the vinylidene species RuCl2(L)(CCHPh)(PPh3) (5(na)). The reaction of 4(nb)-cis-Cl with an excess of ethyl diazoacetate at -60 degrees C gives the novel complex RuCl2(L-na) [cis-EtO(O)C(H)C=QH)QO)OEt} (6(na)) with concomitant elimination of the phosphonium ylide, Ph3P=C(H)C(O)OEt. Whereas 1equiv of diazoalkane thus serves as phosphine scavenger, the uptake of two more carbene units by the remaining 14 e(-) fragment "RuCl2(L-1a)" results in their coupling, providing diethyl maleate, intercepted in 6(na) as a coordinated ligand.Preliminary catalytic tests indicate that the complexes 4(nx) act as catalyst precursors for the ROMP of norbornene in the presence of trimethylsilyldiazomethane as he carbene source. The same compounds 4,,, are also used as catalyst precursors in the transfer hydrogenation of a series of ketone substrates using alcohol as the hydrogen source. For example, the hydrogenation of cyclohexanone is achieved in 99% yield within 45 s with only 0.01 mol (0.1 mol %) of the precatalyst RuCl2(Ph(2)PCH(2)pic)(PPh3)-trans-Cl (4(1a)), representing a turnover frequency of 272 571 h(-1). The X-ray structure analyses of 1, 2(1a), 3(1a), 4(1b) (both trans-Cl and cis-CI isomers), and 6(1a) are reported.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An uncommon synergism in the concerted action of OH- and PR3 toward the simple Ru(II) complex Ru(CO)3Cl2(thf) allows a highly efficient reduction of the metal in ethanol or acetonitrile solution at 0 degrees C, with selective production of the corresponding Roper's-type Ru(0) complexes Ru(CO)2(PR3)3 in high yields within 10 min.