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1.
Hans‐Christian Bttcher Mauricio Fernandez Marion Graf Kurt Merzweiler Christoph Wagner 《无机化学与普通化学杂志》2002,628(11):2247-2248
Activation of Carbon Disulfide on Triruthenium Clusters: Synthesis and X‐Ray Crystal Structure Analysis of [Ru3(CO)4(μ‐PCy2)2(μ‐Ph2PCH2PPh2)(μ3‐S){μ3‐η2‐CSC(S)S}] [Ru3(CO)4(μ‐H)3(μ‐PCy2)3(μ‐dppm)] ( 2 ) (dppm = Ph2PCH2PPh2) reacts with CS2 at room temperature and yields the open 50 valence electron cluster [Ru3(CO)4(μ‐PCy2)2(μ‐dppm)(μ3‐S){μ3‐η2‐CSC(S)S}] ( 3 ) containing the unusual μ3‐η2‐C2S3 mercaptocarbyne ligand. Compound 3 was characterized by single crystal X‐ray structure analysis. 相似文献
2.
Hans‐Christian Bttcher Marion Graf Kurt Merzweiler Christoph Wagner 《无机化学与普通化学杂志》2001,627(12):2657-2662
Activation of Carbon Disulfide on Triruthenium Clusters: Synthesis and X‐Ray Crystal Structure Analysis of [Ru3(CO)5(μ‐H)2(μ‐PCy2)(μ‐Ph2PCH2PPh2){μ‐η2‐PCy2C(S)}(μ3‐S)] and [Ru3(CO)5(CS)(μ‐H)(μ‐PtBu2)(μ‐PCy2)2(μ3‐S)] [Ru3(CO)6(μ‐H)2(μ‐PCy2)2(μ‐dppm)] ( 1 ) (dppm = Ph2PCH2PPh2) reacts under mild conditions with CS2 and yields by oxidative decarbonylation and insertion of CS into one phosphido bridge the opened 50 VE‐cluster [Ru3(CO)5(μ‐H)2(μ‐PCy2)(μ‐dppm){μ‐η2‐PCy2C(S)}(μ3‐S)] ( 2 ) with only two M–M bonds. The compound 2 crystallizes in the triclinic space group P 1 with a = 19.093(3), b = 12.2883(12), c = 20.098(3) Å; α = 84.65(3), β = 77.21(3), γ = 81.87(3)° and V = 2790.7(11) Å3. The reaction of [Ru3(CO)7(μ‐H)(μ‐PtBu2)(μ‐PCy2)2] ( 3 ) with CS2 in refluxing toluene affords the 50 VE‐cluster [Ru3(CO)5(CS)(μ‐H)(μ‐PtBu2)(μ‐PCy2)2(μ3‐S)] ( 4 ). The compound cristallizes in the monoclinic space group P 21/a with a = 19.093(3), b = 12.2883(12), c = 20.098(3) Å; β = 104.223(16)° and V = 4570.9(10) Å3. Although in the solid state structure one elongated Ru–Ru bond has been found the complex 4 can be considered by means of the 31P‐NMR data as an electron‐rich metal cluster. 相似文献
3.
Bis(dimethylamino)trifluoro sulfonium Salts: [CF3S(NMe2)2]+[Me3SiF2]‐, [CF3S(NMe2)2]+ [HF2]‐ and [CF3S(NMe2)2]+[CF3S]‐ From the reaction of CF3SF3 with an excess of Me2NSiMe3 [CF3(NMe2)2]+[Me3SiF2]‐ (CF3‐BAS‐fluoride) ( 5 ), from CF3SF3/CF3SSCF3 and Me2NSiMe3 [CF3S(NMe2)2]+‐ [CF3S]‐ ( 7 ) are isolated. Thermal decomposition of 5 gives [CF3S(NMe2)2]+ [HF2]‐ ( 6 ). Reaction pathways are discussed, the structures of 5 ‐ 7 are reported. 相似文献
4.
Dieter Seebach 《Helvetica chimica acta》2011,94(1):1-17
Fmoc‐β2hSer(tBu)‐OH was converted to Fmoc‐β2hSec(PMB)‐OH in five steps. To avoid elimination of HSeR, the selenyl group was introduced in the second last step (Fmoc‐β2hSer(Ts)‐OAll→Fmoc‐β2hSec(PMB)‐OAll). In a similar way, the N‐Boc‐protected compound was prepared. With the β2hSe‐derivatives, 21 β2‐amino‐acid building blocks with proteinogenic side chains are now available for peptide synthesis. 相似文献
5.
Methyl (2E,4R)‐4‐hydroxydec‐2‐enoate, methyl (2E,4S)‐4‐hydroxydec‐2‐enoate, and ethyl (±)‐(2E)‐4‐hydroxy[4‐2H]dec‐2‐enoate were chemically synthesized and incubated in the yeast Saccharomyces cerevisiae. Initial C‐chain elongation of these substrates to C12 and, to a lesser extent, C14 fatty acids was observed, followed by γ‐decanolactone formation. Metabolic conversion of methyl (2E,4R)‐4‐hydroxydec‐2‐enoate and methyl (2E,4S)‐4‐hydroxydec‐2‐enoate both led to (4R)‐γ‐decanolactone with >99% ee and 80% ee, respectively. Biotransformation of ethyl (±)‐(2E)‐4‐hydroxy(4‐2H)dec‐2‐enoate yielded (4R)‐γ‐[2H]decanolactone with 61% of the 2H label maintained and in 90% ee indicating a stereoinversion pathway. Electron‐impact mass spectrometry analysis (Fig. 4) of 4‐hydroxydecanoic acid indicated a partial C(4)→C(2) 2H shift. The formation of erythro‐3,4‐dihydroxydecanoic acid and erythro‐3‐hydroxy‐γ‐decanolactone from methyl (2E,4S)‐4‐hydroxydec‐2‐enoate supports a net inversion to (4R)‐γ‐decanolactone via 4‐oxodecanoic acid. As postulated in a previous work, (2E,4S)‐4‐hydroxydec‐2‐enoic acid was shown to be a key intermediate during (4R)‐γ‐decanolactone formation via degradation of (3S,4S)‐dihydroxy fatty acids and precursors by Saccharomyces cerevisiae. 相似文献
6.
Novel and Stereospecific Synthesis of (2S)‐3‐(2,4,5‐Trifluorophenyl)propane‐1,2‐diol from D‐Mannitol
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Derya Aktaş Meryem Fıstıkçı Özlem Gündoğdu Hasan Seçen M. Fethi Şahin Ramazan Altundaş Yunus Kara 《Helvetica chimica acta》2015,98(8):1127-1131
A stereospecific synthesis of (2S)‐3‐(2,4,5‐trifluorophenyl)propane‐1,2‐diol from D ‐mannitol has been developed. The reaction of 2,3‐O‐isopropylidene‐D ‐glyceraldehyde with 2,4,5‐trifluorophenylmagnesium bromide gave [(4R)‐2,2‐dimethyl‐1,3‐dioxolan‐4‐yl](2,4,5‐trifluorophenyl)methanol in 65% yield as a mixture of diastereoisomers (1 : 1). The Ph3P catalyzed reaction of the latter with C2Cl6 followed by reduction with Pd/C‐catalyzed hydrogenation gave (2S)‐3‐(2,4,5‐trifluorophenyl)propane‐1,2‐diol with >99% ee and 65% yield. 相似文献
7.
Iliana E. Medina‐Ramírez Mark J. Fink James P. Donahue 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(12):m475-m477
The title compound, [Zn3(C9H21SiS)6] or [(iPr3SiS)Zn(μ‐SSiiPr3)2Zn(μ‐SSiiPr3)2Zn(SSiiPr3)], is the first structurally characterized homoleptic silanethiolate complex of zinc. A near‐linear arrangement of three ZnII ions is observed, the metals at the ends being three‐coordinate with one terminally bound silanethiolate ligand. The central ZnII ion is four‐coordinate and tetrahedral, with two bridging silanethiolate ligands joining it to each of the two peripheral ZnII ions. The nonbonding intermetallic distances are 3.1344 (11) and 3.2288 (12) Å, while the Zn...Zn...Zn angle is 172.34 (2)°. A trimetallic silanethiolate species of this type has not been previously identified by X‐ray crystallography for any element. 相似文献
8.
Vania Denise Schwade Ernesto Schulz Lang Luana Floriano 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(7):517-520
The title compound, [Pb(C4H3N2S)2]n, was prepared by the reaction of [Pb(OAc)2]·3H2O (OAc is acetate) with pyrimidine‐2‐thione in the presence of triethylamine in methanol. In the crystal structure, the PbII atom has an N4S4 coordination environment with four ligands coordinated by N‐ and S‐donor atoms. This compound shows that the pyrimidine‐2‐thiolate anion can lead to a three‐dimensional network when the coordination number of the metal ion can be higher than 6, as is the case with the PbII ion. This compound presents only covalent bonds, showing that despite the possibility of the hemidirected geometries of PbII, the eight‐coordinated ion does not allow the formation of an isolated molecular structure with pyrimidine‐2‐thiolate as the ligand. 相似文献
9.
Substituted 2‐(benzylamino)‐2H‐1,4‐benzoxazin‐3(4H)‐ones are unstable under alkaline and acidic conditions, undergoing opening of the benzoxazinone ring. 2‐Bromo‐2H‐1,4‐benzoxazin‐3(4H)‐ones show similar degradation under alkaline conditions, while replacement of Br at C(2) to give 2‐hydroxy‐2H‐1,4‐benzoxazin‐3(4H)‐ones was observed only under mild alkaline conditions. Mechanisms of ring opening and degradation to 2‐aminophenol derivatives are proposed. 相似文献
10.
Synthesis of (S)-2-Ethoxy-3-Phenylpropanoic Acid Derivatives and Their Insulin-Sensitizing Activity 总被引:1,自引:0,他引:1
A series of (S)-2-ethoxy-3-phenylpropanoic acid derivatives were synthesized and their insulin-sensitizing activities were evaluated in 3T3-L1 cells. Compounds 1b, 1d, 1e and 1f exhibited more potent insulin-sensitizing activity than rosiglitazone. 相似文献
11.
Meng Wen Zu‐Ping Xiao Chun‐Ya Wang Xi‐He Huang 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(2):136-139
The title compound, {[Zn4(C8H4O4)3(OH)2(C12H6N2O2)2]·2H2O}n, has been prepared hydrothermally by the reaction of Zn(NO3)2·6H2O with benzene‐1,4‐dicarboxylic acid (H2bdc) and 1,10‐phenanthroline‐5,6‐dione (pdon) in H2O. In the crystal structure, a tetranuclear Zn4(OH)2 fragment is located on a crystallographic inversion centre which relates two subunits, each containing a [ZnN2O4] octahedron and a [ZnO4] tetrahedron bridged by a μ3‐OH group. The pdon ligand chelates to zinc through its two N atoms to form part of the [ZnN2O4] octahedron. The two crystallographically independent bdc2− ligands are fully deprotonated and adopt μ3‐κO:κO′:κO′′ and μ4‐κO:κO′:κO′′:κO′′′ coordination modes, bridging three or four ZnII cations, respectively, from two Zn4(OH)2 units. The Zn4(OH)2 fragment connects six neighbouring tetranuclear units through four μ3‐bdc2− and two μ4‐bdc2− ligands, forming a three‐dimensional framework with uninodal 6‐connected α‐Po topology, in which the tetranuclear Zn4(OH)2 units are considered as 6‐connected nodes and the bdc2− ligands act as linkers. The uncoordinated water molecules are located on opposite sides of the Zn4(OH)2 unit and are connected to it through hydrogen‐bonding interactions involving hydroxide and carboxylate groups. The structure is further stabilized by extensive π–π interactions between the pdon and μ4‐bdc2− ligands. 相似文献
12.
The preparation of three new N‐Fmoc‐protected (Fmoc=[(9H‐fluoren‐9‐yl)methoxy]carbonyl) β2‐homoamino acids with proteinogenic side chains (from Ile, Tyr, and Met) is described, the key step being a diastereoselective amidomethylation of the corresponding Ti‐enolates of 3‐acyl‐4‐isopropyl‐5,5‐diphenyloxazolidin‐2‐ones with CbzNHCH2OMe/TiCl4 (Cbz=(benzyloxy)carbonyl) in yields of 60–70% and with diastereoselectivities of >90%. Removal of the chiral auxiliary with LiOH or NaOH gives the N‐Cbz‐protected β‐amino acids, which were subjected to an N‐Cbz/N‐Fmoc (Fmoc=[(9H‐fluoren‐9‐yl)methoxy]carbonyl) protective‐group exchange. The method is suitable for large‐scale preparation of Fmoc‐β2hXaa‐OH for solid‐phase syntheses of β‐peptides. The Fmoc‐amino acids and all compounds leading to them have been fully characterized by melting points, optical rotations, IR, 1H‐ and 13C‐NMR, and mass spectra, as well as by elemental analyses. 相似文献
13.
Hsiao‐Fen Wang Kuang‐Hway Yih Weng‐Feng Zeng Shou.‐Ling Huang Gene‐Hsiang Lee 《中国化学会会志》2012,59(8):989-994
Reactions of the thiocarbamoyl‐molybdenum complex [Mo(CO)2(η2‐SCNMe2)(PPh3)2Cl] 1 , and ammonium diethyldithiophosphate, NH4S2P(OEt)2, and potassium tris(pyrazoyl‐1‐yl)borate, KTp, in dichloromethane at room temperature yielded the seven coordinated diethyldithiophosphate thiocarbamoyl‐molybdenum complexe [Mo(CO)2{η2‐S2P(OEt)2}(η2‐SCNMe2)(PPh3)] β‐3 , and tris(pyrazoyl‐1‐yl)borate thiocabamoyl‐molybdenum complex [Mo(CO)2(η3‐Tp)(η2‐SCNMe2)(PPh3)] 4 , respectively. The geometry around the metal atom of compounds β‐3 and 4 are capped octahedrons. The α‐ and β‐isomers are defined to the dithio‐ligand and one of the carbonyl ligands in the trans position in former and two carbonyl ligands in the trans position in later. The thiocabamoyl and diethyldithiophosphate or tris(pyrazoyl‐1‐yl)borate ligands coordinate to the molybdenum metal center through the carbon and sulfur and two sulfur atoms, or three nitrogen atoms, respectively. Complexes β‐3 and 4 are characterized by X‐ray diffraction analyses. 相似文献
14.
The reaction of dialkyl acetylenedicarboxylates 4 with 1‐aryl‐2‐[(3‐arylquinoxalin‐2(1H)‐ylidene)ethanones 3 in the presence of Ph3P leads to dialkyl (2Z)‐2‐[(E)‐1‐aryl‐2‐(3‐arylquinoxalin‐2‐yl)ethenyl]but‐2‐enedioates 1 in good yields. 相似文献
15.
Yang‐Yi Yang Lap Szeto Gang‐Feng Ouyang Zhong‐Qi Huang Wing‐Tak Wong Seik Weng Ng 《应用有机金属化学》2005,19(3):352-353
There are two types of Cd in the title compound, the six‐coordinated Cd atom in the cation is in a distorted octahedral geometry while the four‐coordinated Cd in the anion shows a distorted tetrahedral geometry. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
16.
Hans‐Christian Bttcher Marion Graf Kurt Merzweiler Christoph Wagner 《无机化学与普通化学杂志》2000,626(2):597-603
Coordinatively Unsaturated Diruthenium Complexes: Synthesis and X‐Ray Crystal Structures of [Ru2(CO)4(μ‐H)(μ‐S)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)], [Ru2(CO)4(μ‐X)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] (X = Cl, S2CH) [Ru2(CO)4(μ‐H)(μ‐PtBu2)(μ‐dppm)] ( 1 ) reacts in benzene with elemental sulfur to the addition product [Ru2(CO)4(μ‐H)(μ‐S)(μ‐PtBu2)(μ‐dppm)] ( 2 ) (dppm = Ph2PCH2PPh2). 2 is also obtained by reaction of 1 with ethylene sulfide. The reaction of 1 with carbon disulfide yields with insertion of the CS2 into the Ru2(μ‐H) bridge the dithioformato complex [Ru2(CO)4(μ‐S2CH)(μ‐PtBu2)(μ‐dppm)] ( 3 ). Furthermore, 1 reacts with [NO][BF4] to the complex salt [Ru2(CO)4(μ‐NO)(μ‐H)(μ‐PtBu2)(μ‐dppm)][BF4] ( 4 ), and reaction of 1 with CCl4 or CHCl3 affords spontaneously [Ru2(CO)4(μ‐Cl)(μ‐PtBu2)(μ‐dppm)] ( 5 ) in nearly quantitative yield. The molecular structures of 2 , 3 and 5 were confirmed by crystal structure analyses. 相似文献
17.
The Cd atom in Cd(Hmmi)2I2 is five‐coordinate with a trigonal bipyramidal geometry in which the apical sites are occupied by I and O atoms. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
18.
The synthesis and spectroscopic properties of a Na+ complex with ligand 3-aminopyrazine-2-carboxylic acid were described. The resulting complex was characterized by elemental analysis, IR, UV-Vis, NMR spectroscopy and single crystal X-ray diffraction method. The title compound crystallizes in the triclinic system with space group . The crystalline structure of this compound consists of supramolecular architectures involving strong intramolecular N—H…O in pyrazine molecules and intermolecular O—H…N, O—H…O, and N—H…N hydrogen bonds between substituted pyrazine and water molecules. 相似文献
19.
20.
A convenient one‐pot method for the preparation of (4Z)‐4‐(arylmethylidene)‐5‐ethoxy‐1,3‐oxazolidine‐2‐thiones 2 and 3 from ethyl (2Z)‐3‐aryl‐2‐isothiocyanatoprop‐2‐enoates 1 , which can be easily prepared from ethyl 2‐azidoacetate and aromatic aldehydes, has been developed. Thus, these α‐isothiocyanato α,β‐unsaturated esters were treated with organolithium compounds, including lithium enolates of acetates, to provide 5‐substituted (4Z)‐4‐(arylmethylidene)‐5‐ethoxy‐1,3‐oxazolidine‐2‐thiones, 2 , and 2‐[(4Z)‐(4‐arylmethylidene)‐5‐ethoxy‐2‐thioxo‐1,3‐oxazolidin‐5‐yl]acetates, 3 . 相似文献