Ruthenium complexes with the formulae Ru(CO)2(PR3)2(O2CPh)2 [ 6a – h ; R=n‐Bu, p‐MeO‐C6H4, p‐Me‐C6H4, Ph, p‐Cl‐C6H4, m‐Cl‐C6H4, p‐CF3‐C6H4, m,m′‐(CF3)2C6H3] were prepared by treatment of triruthenium dodecacarbonyl [Ru3(CO)12] with the respective phosphine and benzoic acid or by the conversion of Ru(CO)3(PR3)2 ( 8e – h ) with benzoic acid. During the preparation of 8 , ruthenium hydride complexes of type Ru(CO)(PR3)3(H)2 ( 9g , h ) could be isolated as side products. The molecular structures of the newly synthesized complexes in the solid state are discussed. Compounds 6a – h were found to be highly effective catalysts in the addition of carboxylic acids to propargylic alcohols to give valuable β‐oxo esters. The catalyst screening revealed a considerably influence of the phosphine′s electronic nature on the resulting activities. The best performances were obtained with complexes 6g and 6h , featuring electron‐withdrawing phosphine ligands. Additionally, catalyst 6g is very active in the conversion of sterically demanding substrates, leading to a broad substrate scope. The catalytic preparation of simple as well as challenging substrates succeeds with catalyst 6g in yields that often exceed those of established literature systems. Furthermore, the reactions can be carried out with catalyst loadings down to 0.1 mol% and reaction temperatures down to 50 °C.
New tetranuclear cationic metalla‐bowls 5 – 7 with the general formula [Ru4(p‐cymene)4(N∩N)2(OO∩OO)2]4+ (N∩N=2,6‐bis(N‐(4‐pyridyl carbamoyl)pyridine, OO∩OO=2,5‐dihydroxy‐1,4‐benzoquinonato ( 5 ), OO∩OO=5,8‐dioxydo‐1,4‐naphthaquinonato ( 6 ), OO∩OO=hoxonato ( 7 )) were prepared by the reaction of the respective dinuclear ruthenium complexes 2 – 4 with a bispyridine amide donor ligand 1 in methanol in the presence of AgO3SCF3.These new molecular metalla‐bowls were fully characterized by analytical techniques including elemental analysis as well as 1H and 13C NMR and HR‐ESI‐MS spectroscopy. The structure of metalla‐bowl 6 was determined from X‐ray crystal diffraction data. A UV/visible study was also carried out for the entire suite of new complexes. As with recent studies of similar arene–Ru complexes, the inhibition of cell growth by metalla‐bowls was established against SK‐hep‐1 (liver cancer), AGS (gastric cancer), and HCT‐15 (colorectal cancer) human cancer cell lines. Inhibition of cell growth by 6 was found to be considerably stronger against all cancer cell lines than the anticancer drugs, doxorubicin and cisplatin. In particular, in colorectal cancer cells, expression of the cancer suppressor genes APC and p53 was increased following exposure to 6 . 相似文献
Refluxing a mixture of phthalonitrile C6R1R2R3R4(CN)2 1 (R1–R4=H), or its substituted derivatives 2 (R1, R3, R4=H, R2=Me), or 3 (R1, R4=H, R2, R3=Cl) (1 equiv.) and N,N‐diethylhydroxylamine, Et2NOH, (4 equivs.) in methanol for 4 h results ( Route A ) in precipitation of the symmetrical ( 6 and 8 ) and an isomeric mixture of unsymmetrical ( 7 ) phthalocyanines, isolated in good (55–65 %) yields. The reaction of phthalonitriles 1 , 2 , or 4 (R1, R3, R4=H, R2=NO2) (4 equivs.) with Et2NOH (8 equivs.) in the presence of a metal salt MCl2 (M=Zn, Cd, Co, Ni) (1 equiv.) in n‐BuOH or without solvent results in the formation of metallated phthalocyanine species ( 9 – 17 ). Upon refluxing in freshly distilled dry chloroform, phthalonitrile 1 or its substituted analogues 2 , 3 or 5 (R1–R4=F) (1 equiv.) react with N,N‐diethylhydroxylamine (2 equivs.) affording 3‐iminoisoindolin‐1‐ones 18 – 21 ( Route B ) isolated in good yields (55–80 %). All the prepared compounds were characterized with C, H, and N elemental analyses, ESI‐MS, IR, and compounds 18 – 21 also by 1D (1H, 13C{1H}), and 2D (1H,15N‐HMBC and 1H,13C‐HMQC, 1H,13C‐HMBC) NMR spectroscopy. 相似文献
In situ high‐pressure NMR spectroscopy of the hydrogenation of benzene to give cyclohexane, catalysed by the cluster cation [(η6‐C6H6) (η6‐C6Me6)2Ru3(μ3‐O)(μ2‐OH)(μ2‐H)2]+ 2 , supports a mechanism involving a supramolecular host‐guest complex of the substrate molecule in the hydrophobic pocket of the intact cluster molecule. 相似文献
The new ruthenium‐sulfonate catalyst Ru(Cp*)(η3‐C3H5) (p‐CH3C6H4SO3)2, (Cp*=pentamethylcyclopentadienyl), rapidly and regioselectively mono‐allylates dimedone to the branched products using substituted allyl alcohols as substrates, without acid, base or other additives, under relatively mild conditions. We consider the ruthenium sulfonate to be a “green” alternative in that it uses allyl alcohols as substrate, (rather than carbonates, acetates, etc.) and therefore does not waste the leaving group. The catalyst induces rapid double allylation of various 1,3‐diketones in high yield using allylic alcohol. 相似文献
Construction of gemini‐like surfactants using the cationic single‐chain surfactant cetyltrimethylammonium bromide C16H33N(CH3)3Br2 (CTAB) and the anionic dicarboxylic acid sodium salt NaOOC(CH2)n‐2COONa (CnNa2, n = 4, 6, 8, 10, 12) by way of non‐covalent interactions has been investigated by surface tension measurements, hydrogen‐1 nuclear magnetic resonance (1H NMR) spectroscopy and isothermal titration microcalorimetry (ITC). The critical micelle concentrations (cmc) of the CTAB/CnNa2 mixtures are obviously lower than that of CTAB and strongly depend on the mixing ratio. Moreover, the cmc values of the CTAB/CnNa2 mixtures decrease gradually with an increasing methylene chain length of CnNa2, indicating hydrophobic interaction between the hydrocarbon chains of CTAB and CnNa2 facilitates micellization of the mixtures. In particular, the ITC curves and 1H NMR spectra indicate that the binding ratio of CTAB to CnNa2, except C4Na2, is around 2:1, i.e., (CTAB)2CnNa2. Additionally, CTAB/CnNa2 mixtures are soluble in a whole molar ratio and concentration ranges have been studied, even at the electrical neutralization point. Therefore, these results reveal that highly soluble gemini‐like surfactants are conveniently constructed with oppositely‐charged cationic single‐chain surfactants and dicarboxylic acid sodiums. In an attempt at improving the performance of surfactants this work provides guidance for choosing additives that form gemini‐like surfactants via an uncomplicated synthesis. 相似文献
The energetic material, 3‐nitro‐1,5‐bis(4,4′‐dimethyl azide)‐1,2,3‐triazolyl‐3‐azapentane (NDTAP), was firstly synthesized by means of Click Chemistry using 1,5‐diazido‐3‐nitrazapentane as main material. The structure of NDTAP was confirmed by IR, 1H NMR, and 13C NMR spectroscopy; mass spectrometry, and elemental analysis. The crystal structure of NDTAP was determined by X‐ray diffraction. It belongs to monoclinic system, space group C2/c with crystal parameters a=1.7285(8) nm, b=0.6061(3) nm, c=1.6712(8) nm, β=104.846(8)°, V=1.6924(13) nm3, Z=8, μ=0.109 mm−1, F(000)=752, and Dc=1.422 g cm−3. The thermal behavior and non‐isothermal decomposition kinetics of NDTAP were studied with DSC and TG‐DTG methods. The self‐accelerating decomposition temperature and critical temperature of thermal explosion are 195.5 and 208.2 °C, respectively. NDTAP presents good thermal stability and is insensitive. 相似文献
A stereochemically promiscuous 2‐keto‐3‐deoxygluconate aldolase has been used as an efficient biocatalyst to catalyse the aldol reaction of pyruvate with C3‐ and C4‐aldoses to afford syn‐ and anti‐3‐deoxy‐2‐ulosonic acids in poor to good de. A continuous flow bioreactor containing immobilised aldolase has been developed that enables gram quantities of C6‐ and C7‐3‐deoxyhept‐2‐ulosonic acids to be produced in an efficient manner. 相似文献
The reaction of the Cu(II) bis N,O‐chelate‐complexes of L‐2,4‐diaminobutyric acid, L‐ornithine and L‐lysine {Cu[H2N–CH(COO)(CH2)nNH3]2}2+(Cl–)2 (n = 2–4) with terephthaloyl dichloride or isophthaloyl dichloride gives the polymeric complexes {‐OC–C6H4–CO–NH–(CH2)n–CH(nh2)(COO)Cu(OOC)(NH2)CH–CH2)n–NH‐}x 1 – 5 . From these the metal can be removed by precipitation of Cu(II) with H2S. The liberated ω,ω′‐N,N′‐diterephthaloyl (or iso‐phthaloyl)‐diaminoacids 6 – 10 react with [Ru(cymene)Cl2]2, [Ru(C6Me6)Cl2]2, [Cp*RhCl2]2 or [Cp*IrCl2]2 to the ligand bridged bis‐amino acidate complexes [Ln(Cl)M–(OOC)(NH2)CH–(CH2)nNH–CO]2–C6H4 11 – 14 . 相似文献
Reactions of (CO)5Re(Br), (η5‐C5H5)Ru(Cl)(PPh3)2, and [Pt(μ‐Cl)(C6F5)(S(CH2CH2‐)2)]2 with the alkyne‐containing phosphine Ph2P(CH2)6C≡CCH3 give the bis(phosphine) complexes fac‐(CO)3Re(Br)(Ph2P(CH2)6C≡CCH3)2 ( 5 ), (η5‐C5H5)Ru(Cl)(Ph2P(CH2)6C≡CCH3)2 ( 6 ), and trans‐(Cl)(C6F5)Pt(Ph2P(CH2)6C≡CCH3)2 ( 7 ). Alkyne metatheses with the catalyst (t‐BuO)3W(≡C‐t‐Bu) (10–15 mol %, chlorobenzene, 80 °C) give the seventeen‐membered metallamacrocycles fac‐(CO)3Re(Br)(Ph2P(CH2)6CC(CH2)6P Ph2) ( 8 ), (η5‐C5H5)Ru(Cl)(Ph2P(CH2)6CC(CH2)6P Ph2) ( 9 ), and trans‐(Cl)(C6F5)Pt(PPh2(CH2)6CC(CH2)6P Ph2) ( 10 ). 31P NMR analyses show 90–75% conversions to 8 – 10 (59–47% isolated after chromatography). The identity of 8 was confirmed by a crystal structure, and 10 was hydrogenated over Pd/C to fac‐(CO)3Re(Br)(Ph2P(CH2)6CC(CH2)6P Ph2) ( 12 , 87%), which was crystallographically characterized earlier. A catalyst derived from Mo(CO)6/4‐chlorophenol effects a slower conversion of 7 to 10 at 140 °C. In the case of 5 , a mer, trans isomer of 8 is isolated ( 11 , 44%), as established by NMR and IR data. In 10 – 12 , the diphosphines span trans positions. These results, together with previous examples involving group VIII metallocenes, establish the wide viability of the title reaction. 相似文献
A simple and highly efficient method for the preparation of tetrasubstituted furans starting from readily accessible propargylic alcohols and commercially available 1,3‐dicarbonyl compounds has been developed. The process, which proceeds in a one‐pot manner, involves the initial propargylation of the 1,3‐dicarbonyl compound promoted by trifluoroacetic acid, and subsequent cycloisomerization of the resulting γ‐ketoalkyne catalyzed by the 16‐electron allyl‐ruthenium(II ) complex [Ru(η3‐2‐C3H4Me)(CO)(dppf)][SbF6]. 相似文献
The 16‐electron amide complex, Ru[(R,R)‐TsNCHPhCHPhNH](η6‐p‐cymene) (Ts=p‐toluenesulfonyl, Ph=C6H5) readily reacts with formic acid to give the corresponding formate complex, which subsequently undergoes decarboxylation leading to the hydride complex with release of CO2. The reaction of this hydride complex with CO2 under mild reaction conditions, a pressure of 10 atm and even at −78 °C, proceeds rapidly to give the corresponding formate complex almost quantitatively. Thus, the reversible decarboxylation and carboxylation takes place with or without the aid of a metal‐NH bifunctional effect of the Ru complexes. 相似文献
The purple photosynthetic bacterium Rhodospirillum centenum has a putative type III polyketide synthase gene (rpsA). Although rpsA was known to be transcribed during the formation of dormant cells, the reaction catalyzed by RpsA was unknown. Thus we examined the RpsA reaction in vitro, using various fatty acyl‐CoAs with even numbers of carbons as starter substrates. RpsA produced tetraketide pyranones as major compounds from one C10–14 fatty acyl‐CoA unit, one malonyl‐CoA unit and two methylmalonyl‐CoA units. We identified these products as 4‐hydroxy‐3‐methyl‐6‐(1‐methyl‐2‐oxoalkyl)pyran‐2‐ones by NMR analysis. RpsA is the first bacterial type III PKS that prefers to incorporate two molecules of methylmalonyl‐CoA as the extender substrate. In addition, in vitro reactions with 13C‐labeled malonyl‐CoA revealed that RpsA produced tetraketide 6‐alkyl‐4‐hydroxy‐1,5‐dimethyl‐2‐oxocyclohexa‐3,5‐diene‐1‐carboxylic acids from C14–20 fatty acyl‐CoAs. This class of compounds is likely synthesized through aldol condensation induced by methine proton abstraction. No type III polyketide synthase that catalyzes this reaction has been reported so far. These two unusual features of RpsA extend the catalytic functions of the type III polyketide synthase family. 相似文献