Reactions of Tungsten Propargyl and Allenyl Complexes with Hydrido Triosmium Cluster: Molecular and Crystal Structure of Cp(CO)2[P(OMe)3]W(μ, η1, η2-CH2CH=CH)OS3(CO)10H and H2(CH2CH = CH)2Os6(CO)20

Reactions of H₂Os₃(CO)₁₀, 3, with the monophosphite-substituted and non-substituted tungsten propargyl and allenyl carbonyl complexes Cp(CO)₂LWCH₂C≡CH (1a, L = CO; 1b, L = P(OMe)₃) and Cp(CO)₂LWCH = C = CH₂ (2a, L = CO; 2b, L = P(OMe)₃) were investigated. In the reaction of 1b with 3, a tetranuclear complex 4b is obtained. The molecules of 4b crystallize as Cp(CO)₂[P(OMe)₃]W(μ, η¹, η²-CH₂CH=CH)(μ-H)Os₃(CO)_l0 in space group PI with a = 9.490 (4), b = 13.072 (7), c = 13.770 (9) Å, α = 91.89 (5), β = 106.71 (5), γ = 104.07(4)°, V = 1577(2) ų, Z = 2. In the reaction of 2a with 3, from the reaction mixture exposed to air followed by workup using silica-gel packed column chromatography, a complex consisting of two triosmium clusters bridged by a hexadiene ligand from the coupling of allenyl ligand was obtained. The molecules of the hexanuclear complex crystallize as [CH₂CH = CH)₂(μH)₂OS₆(CO)₂₀in space group P2₁/c with a = 14.448 (7), b = 13.689 (4), c = 19.224 (4) Å, β = 107.14(3)°, V = 3633 (2) Å Z = 4.     

Gold‐catalyzed Reactions of 3‐Alkynyloxireno[2, 3‐b]chromenones to Form 3(2H)‐Furanones via a Domino Pathway

3(2H)‐Furanones are efficiently generated from 3‐alkynyl oxireno[2,3‐b]chromenones by an Au/DDQ‐catalyzed domino reaction through a pathway composed of cyclization, C? C cleavage, nucleophilic addition, oxidation, and nucleophilic addition. It was found that stoichiometric AuCl₃ or catalytic Au with stoichiometric DDQ can oxidize the benzylic sp³ C? H bond to facilitate nucleophilic addition.     

Syntheses,and Crystal Structures of Indium Complexes with η2‐Piperidinyldithiocarbamate and η2‐Pyridine‐2‐Thionate Containing Ligands: Structures of [In(η2‐S2CNC5H10)3] and [In(η2‐pyS)3]

The η²‐thio‐indium complexes [In(η²‐thio)₃] (thio = S₂CNC₅H₁₀, 2 ; SNC₄H₄, (pyridine‐2‐thionate, pyS, 3 ) and [In(η²‐pyS)₂(η²‐acac)], 4 , (acac: acetylacetonate) are prepared by reacting the tris(η²‐acac)indium complex [In(η²‐acac)₃], 1 with HS₂CNC₅H₁₀, pySH, and pySH with ratios of 1:3, 1:3, and 1:2 in dichloromethane at room temperature, respectively. All of these complexes are identified by spectroscopic methods and complexes 2 and 3 are determined by single‐crystal X‐ray diffraction. Crystal data for 2 : space group, C2/c with a = 13.5489(8) Å, b = 12.1821(7) Å, c = 16.0893(10) Å, β = 101.654(1)°, V = 2600.9(3) ų, and Z = 4. The structure was refined to R = 0.033 and Rw = 0.086; Crystal data for 3 : space group, P2₁ with a = 8.8064 (6) Å, b = 11.7047 (8) Å, c = 9.4046 (7) Å, β = 114.78 (1)°, V = 880.13(11) ų, and Z = 2. The structure was refined to R = 0.030 and Rw = 0.061. The geometry around the metal atom of the two complexes is a trigonal prismatic coordination. The piperidinyldithiocarbamate and pyridine‐2‐thionate ligands, respectively, coordinate to the indium metal center through the two sulfur atoms and one sulfur and one nitrogen atoms, respectively. The short C‐N bond length in the range of 1.322(4)–1.381(6) Å in 2 and C‐S bond length in the range of 1.715(2)–1.753(6) Å in 2 and 3 , respectively, indicate considerable partial double bond character.     

Novel butterfly tungsten-osmium carbido cluster Complexes from the reaction of Os3(CO)10(NCME)2 CPW(CO)3(CH2SMe)

Condensation of be triosmium acetonitrile complex Os₃(CO)₁₀(NCMe)₂ with the sulfido complex CpW(CO)₃(CH₂SMe) in refluxing THF solution produced three sulfur-containing compounds Os₃(C0)₁₀)(µ-H)(µ-SMe) (1), Os₃(CO)₁₁ [S(Me)CH₂W(CO)₃Cp] (2) and CpWOs₃(CO)₁₂(µ-CH₂)(µ-SMe) (3). Clusters 2 and 3 were products involving a 1:1 combination of starting materials and were characterized by X-ray diffraction studies. Crystals of 2 belongs to monoclinic space group P 2₁ /c witha=8.418(2),b = 11.912(2),c = 28.288 Å,=97.64(2)°,Z=4;R _F=0.044,R _W,=0.044. Crystal dara far 3: space group P 2₁/e,a 18.156(4).b=9.255(6),c = 15.347(4) Å. = 103.49(2)°,Z = 4;R _F -=0.047,R _W = 0.045. Upon thermolysis in toluene, the methylene cluster 3 released CO and induced C-H bond activation to afford two tetrametallic carbido clusters with formula CPWOS₃(CO)₉(µ₄-C)(µ-H)₂(µ-SMe) (4) and CPWOs₃(CO)₁₁(µ₄-C)(µ-SMe) (5) as the principle products. The first complex possesses a butterfly framework encapsulating a µ₄-C ligmd and a µ-SMe ligand linking a W-Os edge, whereas the second product adopts a puckered, cyclic arrangement of WOs₃ metal atoms with µ-SMe ligand located on a nonbonding Os-Os vector. Complex4 crystallizes in monoclinic space group P 2₁ /c witha=15.633(4) Å,b = 8.699 (3) Å,c=15.422(4) Å,=93.12(2)=°, Z=4,R=0.036,R _W =0.034 for 2780 observed reflections. Crystal data for5: space groupP nma,a=14.542(3),b=13.710(6),c=11.758(3) Å.Z=4,R _F =0.038,R _W = 0.037 for 1826 observed reflections. A variable temperature¹H NMR study was also presented to demonstrate the solution fluxionality of5.     

Pincer ligand coordination at a triosmium cluster: X-ray structures of 1,2-Os3(CO)10[4,6-bis(diphenylphosphinomethyl)-m-xylene] and 1,2-Os3(CO)10[1-diphenylphosphino-1-{(2,4-dimethyl-5-diphenylphosphinomethyl)phenyl}-propan-2-ol]

The reaction between the triosmium cluster 1,2-Os₃(CO)₁₀(MeCN)₂ and the diphosphine pincer ligand 4,6-bis(diphenylphosphinomethyl)-m-xylene (dppx) has been examined and found to yield the pincer-bridged cluster 1,2-Os₃(CO)₁₀(dppx) (2) as the major product, in addition to the pincer-bridged cluster 1,2-Os₃(CO)₁₀[1-diphenylphosphino-1-{(2,4-dimethyl-5-diphenylphosphinomethyl)phenyl}-propan-2-ol] (3) in trace amounts (<2% yield). Both cluster products have been isolated and their molecular structures determined by crystallographic analyses. The structural highlights of compounds 2 and 3, which represent the first examples of pincer-ligated metal clusters, are discussed. The origin of the functionalized diphosphine ligand in 3 is traced to the ethanol solvent that was used in the recrystallization of the dppx ligand.     

Enantioselective Total Synthesis of 3β‐Hydroxy‐7β‐kemp‐8(9)‐en‐6‐one,a Diterpene Isolated from Higher Termites

The first total synthesis of the title diterpene was accomplished starting from the Wieland–Miescher ketone. A diastereoselective sulfa‐Michael addition enabled the generation of the delicate β,γ‐unsaturated ketone moiety, while the tetracyclic kempane skeleton was readily constructed through domino metathesis.     

Cluster chemistry. 61. Addition of HX (XCl,Br,I) or AuCl(PPh3) to an open Ru5 cluster. X-ray structures of Ru5(μ-H)(μ5-C2PPh2)(μ-PPh2)(μ-Br)(CO)13 and Ru5(μ-H)(μ5-C2PPh2)(μ3-I)(μ-PPh2)(CO)12

Reactions of aqueous HX (X?Cl, Br) or of AuCl(PPh₃) with Ru₅(μ₅-C₂PPh₂)(μ-PPh₂)(CO)₁₃ result in addition of the 4e-donor set (H + X) or (Au(PPh₃) + Cl) with concomitant opening of two Ru? Ru bonds to give complexes containing dimetallated triangular of ‘scorpion’ cores. Aqueous HI reacts similarly, but in this case the iodide ligand spans three Ru atoms, the (H + I) set acting as 6e-donor. The structures of the two title compounds were confirmed by X-ray crystallographic studies. Ru₅(μ-H)(μ₅-C₂PPh₂)(μ-PPh₂)-(μ-Br)(CO)₁₃ is triclinic, space group P1 , a = 9.689(2), b = 11.874(2), c = 20.005(4) Å, α = 84.66(2), β = 82.90(6), λ = 67.51(6)°, Z = 2; 6478 data with I > 2σ(I) were refined to R = 0.0368, R_w = 0.0362. Ru₅(μ-H)(μ₅-C₂PPh₂)(μ₃-I)(μ-PPh₂)-(CO)₁₂.CH₂Cl₂ is monoclinic, space group P2₁/n, a = 14.809(4), b = 20.721(4), c = 17.698(5) Å, β = 111.42(2)°, Z = 4; 7815 data with I > 2σ(I) were refined to R = 0.0440, R_w = 0.0416.     

Isomerization and conformational transformations of theN-allyl-N-methylcarbamoyl bridging ligand in the (μ-H)Os3{μ-OCN(Me)CH2CH=CH2}(CO)10 complex

The (μ-H)Os₃{μ-OCN(Me)CH₂CH=CH₂}(CO)₁₀ complex containing an allylic fragment in theN,N-dialkylsubstituted carbamoyl briding ligand was synthesized. The stereo-chemical behavior of this complex in solution was investigated. As follows from the NMR spectral data, the complex undergoes reversible conformational (about the amide C−N bond) and irreversible allylic isomerization. Both conformers were isolated in the solid state by chromatography at a reduced temperature. The allylic isomerization occurs stereospecifically to produce the (μ-H)Os₃{μ-OCN(Me)CH=CHMe}(CO)₁₀ complex with thetrans-oriented olefinic hydrogen atoms. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 158–162, January, 1998.     

Pd(II) complexes bearing di‐ and monochelate fluorinated β‐ketonaphthyliminato ligand and their catalytic properties towards vinyl‐addition polymerization and copolymerization of norbornene and ester‐functionalized norbornene derivative

Fluorinated β‐ketonaphthyliminate ligand CF₃C(O)CHC[HN(naphthyl)]CH₃ ( L1 ) and Pd(II) complexes with dichelate fluorinated β‐ketonaphthyliminato ligand, {CF₃C(O)CHC[N(naphthyl)]CH₃}₂Pd ( C1 ), as well as with monochelate fluorinated β‐ketonaphthyliminato ligand, {CF₃C(O)CHC[N(naphthyl)]CH₃}Pd(CH₃)(PPh₃) ( C2 ), were synthesized and their solid‐state structures were confirmed using X‐ray crystallographic analysis. The Pd(II) complexes were employed as precursors to catalyze norbornene (NB) homo‐ and copolymerization with ester‐functionalized NB derivative using B(C₆F₅)₃ as a co‐catalyst. High activity up to 2.3 × 10⁵ g_polymer mol_Pd^?1 h^?1 for the C1 /B(C₆F₅)₃ system and 3.4 × 10⁶ g_polymer mol_Pd^?1 h^?1 for the C2 /B(C₆F₅)₃ system was exhibited in NB homopolymerization. Moreover, the Pd(II) complexes exhibited a high level of tolerance towards the ester‐functionalized MB monomer. In comparison with the C1 /B(C₆F₅)₃ system, the C2 /B(C₆F₅)₃ system exhibited better catalytic property towards the copolymerization of NB with 5‐norbornene‐2‐carboxylic acid methyl ester (NB‐COOCH₃), and soluble vinyl‐addition‐type copolymers were obtained with relatively high molecular weights (3.6 × 10⁴–7.5 × 10⁴ g mol^?1) as well as narrow molecular weight distributions (1.49–2.15) depending on the variation of monomer feed ratios. The NB‐COOCH₃ insertion ratio in all copolymers could be controlled in the range 2.8–21.0 mol% by tuning a content of 10–50 mol% NB‐COOCH₃ in the monomer feed ratios. Copolymerization kinetics were expressed by the NB and NB‐COOCH₃ monomer reactivity ratios: r_NB‐COOCH3 = 0.18, r_NB = 1.28 were determined for the C1 /B(C₆F₅)₃ system and r_NB‐COOCH3 = 0.19, r_NB = 3.57 for the C2 /B(C₆F₅)₃ system using the Kelen–Tüdõs method. Copyright © 2014 John Wiley & Sons, Ltd.