HC CC Research Articles

Luminescent early-late-hetero-tetranuclear group IV - Au(I) bisamidinate complexes.

The versatile metalloligand [{HCCC(NDipp)2}2Au2] (dipp = 2,6-diisopropylphenyl) was converted into early-late heterotetrametallic complexes [{ClCp2MCCC(NDipp)2}2Au2] (M = Ti, Zr). These compounds show photoluminescence with either remarkably different (Ti) or similar (Zr) features as compared to related solely coinage metal containing acetylide amidinate complexes.

Study of the Relationship between Microbiome and Colorectal Cancer Susceptibility Using 16SrRNA Sequencing.

A lot of previous studies have recently reported that the gut microbiota influences the development of colorectal cancer (CRC) in Western countries, but the role of the gut microbiota in Chinese population must be investigated fully. The goal of this study was to determine the role of the gut microbiome in the initiation and development of CRC. We collected fecal samples of 206 Chinese individuals: 59 with polyp (group P), 54 with adenoma (group A), 51 with colorectal cancer (group CC), and 42 healthy controls (group HC).16S ribosomal RNA (rRNA) was used to compare the microbiota community structures among healthy controls, patients with polyp, and those with adenoma or colorectal cancer. Our study proved that intestinal flora, as a specific indicator, showed significant differences in its diversity and composition. Sobs, Chao, and Ace indexes of group CC were significantly lower than those of the healthy control group (CC group: Sobs, Chao, and Ace indexes were 217.3 ± 69, 4265.1 ± 80.7, and 268.6 ± 78.1, respectively; HC group: Sobs, Chao, and Ace indexes were 228.8 ± 44.4, 272.9 ± 58.6, and 271.9 ± 57.2, respectively). When compared with the healthy individuals, the species richness and diversity of intestinal flora in patients with colorectal cancer were significantly reduced: PCA and PCoA both revealed that a significant separation in bacterial community composition between the CC group and HC group (with PCA using the first two principal component scores of PC1 14.73% and PC2 10.34% of the explained variance, respectively; PCoA : PC1 = 14%, PC2 = 9%, PC3 = 6%). Wilcox tests was used to analyze differences between the two groups, it reveals that Firmicutes (P=0.000356), Fusobacteria (P=0.000001), Proteobacteria (P=0.000796), Spirochaetes (P=0.013421), Synergistetes (P=0.005642) were phyla with significantly different distributions between cases and controls. The proportion of microorganism composition is varying at different stages of colon cancer development: Bacteroidetes (52.14%) and Firmicutes (35.88%) were enriched in the healthy individuals; on the phylum level, the abundance of Bacteroidetes (52.14%-53.92%-52.46%–47.06%) and Firmicutes (35.88%-29.73%-24.27%–25.36%) is decreasing with the development of health-polyp-adenomas-CRC, and the abundance of Proteobacteria (9.33%-12.31%-16.51%–22.37%) is increasing. PCA and PCOA analysis showed there was no significant (P < 0.05) difference in species similarity between precancerous and carcinogenic states. However, the composition of the microflora in patients with precancerous lesions (including patients with adenoma and polyp) was proved to have no significant disparity (P < 0.05). Our study provides insights into new angles to dig out potential biomarkers in diagnosis and treatment of colorectal cancer and to provide scientific advice for a healthy lifestyle for the sake of gut microbiota.

Elevated Serum IgE May be Associated with Development of Ketamine Cystitis

Previous studies revealed bladder mast cell and eosinophil cell infiltration in patients with ketamine cystitis. Due to possible hypersensitivity in those with this condition we investigated the association of serum Ig, histology findings and symptoms in patients with ketamine cystitis. We evaluated patients with ketamine cystitis for maximal bladder capacity, serum IgE, IgG and IgM, and pain visual analog scale score. Bladder biopsies were assessed for mast cells and eosinophils. Patients with interstitial cystitis/bladder pain syndrome, acute bacterial cystitis and controls were also studied. We used the Mann-Whitney U test for nonparametric data to compare serum IgE among groups with p <0.017 considered significant. Median serum IgE was significantly higher in the 20 patients withketamine cystitis (205.5 IU/ml, IQR 36.9, 514.0) than in the 10 controls (33.4 IU/ml, IQR 13.5, 71.7, p = 0.015) and the 15 with acute bacterial cystitis (34.6 IU/ml, IQR 24.2, 101.9, p = 0.015). It was marginally higher than in the 13patients withinterstitial cystitis/bladder pain syndrome (65.8 IU/ml, IQR 11.9, 133.0, p = 0.029). Of patients with ketamine cystitis the median visual analog scale pain score was significantly higher in those with serum IgE greater than compared to less than 200 IU/ml. Maximal bladder capacity was significantly less in patients with ketamine cystitis who had higher IgE. Patients with severe or moderate bladder eosinophil infiltration had a greater visual analog scale score, higher serum IgE and smaller maximal bladder capacity than patients with no or mild eosinophil infiltration. Serum IgE and the visual analog scale score correlated significantly (r(2) = 0.318, p = 0.01). Patients with ketamine cystitis had higher serum IgE than patients with interstitial cystitis/bladder pain syndrome or acute bacterial cystitis, or controls. Serum IgE and the severity of eosinophil infiltration were associated with bladder pain severity and small maximal bladder capacity.

ChemInform Abstract: Ruthenium Carboxylate Complexes as Easily Prepared and Efficient Catalysts for the Synthesis of β‐Oxopropyl Esters.

Abstract The easily prepared complex cis-[Ru(κ2-O2CMe)2(PPh3)2] is an effective catalyst for the addition of carboxylic acids to propargyl alcohols to afford β-oxopropyl esters. The reaction is tolerant to a range of functional groups on the propargyl alcohol and is effective in the case of the steroid ethisterone. An investigation into the ruthenium-containing products from the reaction involving benzoic acid revealed that rapid exchange between coordinated acetate and benzoate ligands occurs. The synthesis of crystallographically characterised cis-[Ru(κ2-O2CPh)2(PPh3)2] was developed. This benzoate-substituted complex was shown to react with HC CPh and HC CC(OH)PhH to give [Ru(κ2-O2CPh)(κ1-O2CPh)( C CPhH)(PPh3)2] and [Ru(κ2-O2CPh)(κ1-O2CPh)( C CC{OH}PhH)(PPh3)2] respectively. Reaction of cis-[Ru(κ2-O2CPh)2(PPh3)2] with CO affords [Ru(κ2-O2CPh)(κ1-O2CPh)(CO)(PPh3)2] or [Ru(κ2-O2CPh)2(CO)2(PPh3)2] depending on the conditions employed. Related carbonyl compounds are thought to be the ruthenium-containing products from the catalytic reactions and [Ru(κ2-O2CMe)(κ1-O2CMe)(CO)(PPh3)2] was also shown to be a competent catalyst.

Syntheses and structures of thermally stable diketiminato complexes of gold and copper

While most metallic elements across the Periodic Table form stable chelating β-diketiminato complexes, examples of Au(I) are conspicuous by their absence. We report here the reaction of K[HC(F(3)CC=NR)(2)] with AuCl(PPh(3)) which provides a rare example of a thermally stable gold(I) diketiminato complex, (Ph(3)P)Au[RN=C(CF(3))CH(CF(3))C=NR] [R = 3,5-C(6)H(3)(CF(3))(2)]. The complex is highly fluxional in solution but in the solid state adopts a U-conformation. By contrast, the analogous reaction of K[HC(F(3)CC=NR)(2)] with CuBr(PPh(3))(3) gives the rigid 18-electron chelate complex (Ph(3)P)(2)Cu[κ(2)-HC{(CF(3))C=NR}(2)].

Ruthenium carboxylate complexes as easily prepared and efficient catalysts for the synthesis of β-oxopropyl esters

The easily prepared complex cis-[Ru(κ 2-O 2CMe) 2(PPh 3) 2] is an effective catalyst for the addition of carboxylic acids to propargyl alcohols to afford β-oxopropyl esters. The reaction is tolerant to a range of functional groups on the propargyl alcohol and is effective in the case of the steroid ethisterone. An investigation into the ruthenium-containing products from the reaction involving benzoic acid revealed that rapid exchange between coordinated acetate and benzoate ligands occurs. The synthesis of crystallographically characterised cis-[Ru(κ 2-O 2CPh) 2(PPh 3) 2] was developed. This benzoate-substituted complex was shown to react with HC CPh and HC CC(OH)PhH to give [Ru(κ 2-O 2CPh)(κ 1-O 2CPh)( C CPhH)(PPh 3) 2] and [Ru(κ 2-O 2CPh)(κ 1-O 2CPh)( C CC{OH}PhH)(PPh 3) 2] respectively. Reaction of cis-[Ru(κ 2-O 2CPh) 2(PPh 3) 2] with CO affords [Ru(κ 2-O 2CPh)(κ 1-O 2CPh)(CO)(PPh 3) 2] or [Ru(κ 2-O 2CPh) 2(CO) 2(PPh 3) 2] depending on the conditions employed. Related carbonyl compounds are thought to be the ruthenium-containing products from the catalytic reactions and [Ru(κ 2-O 2CMe)(κ 1-O 2CMe)(CO)(PPh 3) 2] was also shown to be a competent catalyst.

Dimerisation and reactivity of HC [tbnd]CC [tbnd]CFc at ruthenium centres

In contrast to the simple diynyl complexes formed in reactions between HC CC CFc and MCl(dppe)Cp∗; (M = Fe, Ru), an analogous reaction with RuCl(PPh 3) 2Cp∗; in the presence of KPF 6 and dbu resulted in dimerisation of the diyne at the Ru centre to afford a mixture of [Ru{η 1,η 2-C(C CFc) C(L)CH CC CHFc}(PPh 3)Cp∗]PF 6 (L = dbu 1, PPh 3 2). Similar reactions with RuCl(PR 3) 2L gave [Ru{η 1,η 2-C(C CFc) C(dbu)CH CC CHFc}(PR 3)L]PF 6 (L = Cp, R = Ph 3, m-tol 4; L = η 5-C 9H 7, R = Ph 5). The reaction between 3 and I 2, followed by crystallization of the paramagnetic product from MeOH, afforded the dicationic [Ru{C(C CFc)C(dbu)CH C(OMe)C(OMe) CHFc}(PPh 3)Cp](I 3) 2 6. The molecular structures of 2·2CH 2Cl 2 and 6.S (S = 2CH 2Cl 2, C 6H 6) were determined by single-crystal XRD studies.

Reactions of Co 2(CO) 8 and of Co 2(CO) 6L (L = 3-pentyn-1-ol, 1,4-butyn-diol or 2-methyl-3-butyn-2-ol) with 2(diphenylphosphino)ethyl-trietoxysilane and tris(hydroxymethyl)phosphine for applications to new sol–gel materials

The complex Co 2(CO) 6[μ-η 2-(H 3CC CCH 2CH 2OH)] ( 1) with the ligand 3-pentyn-1-ol ( pol) has been synthesized following established procedures. Its structure has been determined by X-ray analysis. The complex Co 2(CO) 6( mbo) ( mbo = 2-methyl-3-butyn-2-ol, HC CC(CH 3) 2OH), ( 3), along with the already known Co 2(CO) 6( bud) ( bud = 1,4-butyn-diol, HOCH 2C CCH 2OH) ( 2), and Co 2(CO) 8 were reacted with 2(diphenylphosphino)ethyl-triethoxysilane [Ph 2PCH 2CH 2Si(OCH 2CH 3) 3] ( dpts) and tris(hydroxymethyl)phosphine [P(CH 2OH) 3] ( thp). With dpts, mono- and di-substituted complexes were obtained: these were characterized by analytical and spectroscopic techniques. The structures of Co 2(CO) 6( dpts) 2 ( 5) and of Co 2(CO) 4( pol)( dpts) 2 ( 8) have been determined by X-ray analysis. Complex ( 1) was reacted with 3-(triethoxysilyl)propyl isocyanate [(H 3CCH 2O) 3Si(CH 2) 3NCO] ( tsi): the new complex Co 2(CO) 6[H 3CC CCH 2CH 2OC( O)NH(CH 2) 3Si(OCH 2CH 3) 3] ( 9) was obtained and spectroscopically characterized. The complex has also been reacted with tetraethyl orthosilicate ( teos); a new inorganic–organometallic material was obtained. Complex ( 5) has been grafted on the mesoporous material SBA-15. The hybrid inorganic–organometallic materials obtained have been characterized by inductively coupled plasma-mass spectrometry (ICP-MS), infrared spectroscopy (FT-IR) under vacuum conditions, X-ray diffraction (XRD) and scanning electron microscopy coupled to EDS probe (SEM–EDS).

The overexpression of polycomb group proteins Bmi1 and EZH2 is associated with the progression and aggressive biological behavior of hepatocellular carcinoma

Polycomb-group proteins Bmi1 and EZH2 are involved in the malignant transformation and biological aggressiveness of several human carcinomas. We herein examined the significance of the Bmi1 and EZH2 expression in hepatocellular carcinoma (HCC) and its preneoplastic lesions, dysplastic nodules. The expression of Bmi1 and EZH2 were examined immunohistochemically in HCC (n=27) and dysplastic nodules (n=14), and combined hepatocellular and cholangiocarcinoma (HC-CC) (n=14). The effect of Bmi1 and EZH2 knockdown was examined in cultured HCC cells (HuH7 and HepG2) using siRNA. It was determined that Bmi1 was constantly expressed in cholangiocytes, but not in hepatocytes, and EZH2 was detected in neither cholangiocytes nor hepatocytes. Bmi1 and EZH2 were overexpressed in HCC and more extensively in HC–CC (P<0.01). Interestingly, Bmi1 and EZH2 were not overexpressed in the dysplastic nodules. The expression of Bmi1 and EZH2 was heterogeneous and associated with vascular infiltration, the histological grades, and the cell proliferation activity in HCC and HC–CC. In cultured carcinoma cells overexpressing Bmi1 and EZH2, knockdown of Bmi1 and EZH2 resulted in decreased cell proliferation activities. Therefore, the overexpression of polycomb-group proteins Bmi1 and EZH2 is associated with the malignant progression of HCC, thereby reflecting the aggressive biological behavior in HCC and HC–CC.

Luminescent Au 3Ag 6 heterononanuclear complex of 1-ethynylcyclopentanol

Reaction of polymeric species (AgC CC 5H 8OH) n (HC CC 5H 8OH = 1-ethynylcyclopentanol) with binuclear precursor [Au 2(μ-dppm) 2](PF 6) 2 (dppm = bis(diphenylphospnino)methane) caused isolation of Au 3Ag 6 heterononanuclear complex [Au 3Ag 6(μ-dppm) 3(μ 3– η 1-C CC 5H 8OH) 6](PF 6) 3. The Au 3Ag 6 (μ 3-C CC 5H 8OH) 6 skeleton exhibits a hexagonal prismatic structure formed by μ 3–η 1-C CC 5H 8OH bound to the Au 3Ag 6 cluster core. The compound is luminescent in both solid state and dichloromethane at both 298 and 77 K with the room temperature lifetimes in microsecond ranges, suggesting an emissive triplet parentage.

Intrahepatic cholangiocarcinoma arising in cirrhotic liver frequently expressed p63-positive basal/stem-cell phenotype

In general, intrahepatic cholangiocarcinoma (ICC) is not related to liver cirrhosis. However, a few cases have been reported in which ICC was accompanied by severe liver fibrosis. Some researchers have proposed that hepatocellular and cholangiocellular (HC–CC) carcinoma, an intermediate mixed phenotype possibly arising in cirrhotic liver, might originate from hepatic precursor cells. In the liver, hepatocytes and cholangiocytes form the epithelial element, but stromal and mesenchymal elements may be produced by hepatic stem cells. Based on these aspects, not only HC–CC, but also other combinations of cellular phenotypes, would cover all the cancers with stem cell features. In this study, which aimed at determining the characteristics of the ICC phenotype, we used immunohistochemistry to examine the expression of basal/stem-cell markers, i.e., p63 in ICC with and without liver cirrhosis, as well as the expressions of cytokeratin (CK) 34 beta E12, specific for the basal-cell marker, and c-kit, specific for the stem-cell marker. Aberrant p63 was frequently expressed in ICC arising in cirrhotic liver. This result suggests that ICC cancer cells originate from hepatic precursor cells with a hidden multi-differentiation potential.

Reaction of the RuTp(PR 3)Cl fragment with alkynols: Formation of carbene, vinylidene, allenylidene, and carbyne complexes

The reaction of RuTp(COD)Cl ( 1) with PR 3 (PR 3 = PPh 2 i Pr, P i Pr 3, PPh 3) and propargylic alcohols HC CCPh 2OH, HC CCFc 2OH (Fc = ferrocenyl), and HC CC(Ph)MeOH has been studied.In the case of PR 3 = PPh 2 i Pr, P i Pr 3 and HC CCPh 2OH, the 3-hydroxyvinylidene complexes RuTp(PPh 2 i Pr)( C CHC(Ph) 2OH)Cl ( 2a) and RuTp(P i Pr 3)( C CHC(Ph 2)OH)Cl ( 2b) were isolated.With PR 3 = PPh 2 i Pr and HC CCFc 2OH as well as with PR 3 = PPh 3 and HC CCPh 2OH dehydration takes place affording the allenylidene complexes RuTp(PPh 2 i Pr)( C C CFc 2)Cl ( 3b) and RuTp(PPh 3)( C C CPh 2)Cl ( 3c).Similarly, with PPh 2 i Pr and HC CC(Ph)MeOH rapid elimination of water results in the formation of the vinylvinylidene complex RuTp(PPh 2 i Pr)( C CHC(Ph) CH 2)Cl ( 4).In contrast to the reactions of the RuTp(PR 3)Cl fragment with propargylic alcohols, with HC C(CH 2) n OH ( n = 2, 3, 4, 5) six-, and seven-membered cyclic oxycarbene complexes RuTp(PR 3)( C 4H 6O)Cl ( 5), RuTp(PR 3)( C 5H 8O)Cl ( 6), and RuTp(PR 3)( C 6H 10O)Cl ( 7) are obtained. On the other hand, with 1-ethynylcyclohexanol the vinylvinylidene complex RuTp(PPh 2 i Pr)( C CHC 6H 9)Cl ( 8) is formed. The reaction of the allenylidene complexes 3a– c with acid has been investigated. Addition of CF 3COOH to a solution of 3a– c resulted in the reversible formation of the novel RuTp vinylcarbyne complexes [RuTp(PPh 2 i Pr)( C–CH CPh 2)Cl] + ( 9a), [RuTp(PPh 2 i Pr)( C–CH CFc 2)Cl] + ( 9b), and [RuTp(PPh 3)( C–CH CPh 2)Cl] + ( 9c). The structures of 3a, 3b, and 5b have been determined by X-ray crystallography.

Synthesis and reactivity of hydride and dihydrogen complexes of ruthenium with tris(pyrazolyl)borate and phosphite ligands

Chloro phosphite complexes RuClTpL(PPh 3) ( 1a, 1b) [L = P(OEt) 3, PPh(OEt) 2] and RuClTp[P(OEt) 3] 2 ( 1c) [Tp = hydridotris(pyrazolyl)borate] were prepared by allowing RuClTp(PPh 3) 2 to react with an excess of phosphite. Treatment of the chloro complexes 1 with NaBH 4 in ethanol yielded the hydride RuHTpL(PPh 3) ( 2a, 2b) and RuHTp[P(OEt) 3] 2 ( 2c) derivatives. Protonation reaction of 2 with Brønsted acids was studied and led to thermally unstable (above 10 °C) dihydrogen [Ru(η 2- H 2)TpL(PPh 3)] + ( 3a, 3b) and [Ru(η 2-H 2)Tp{P(OEt) 3} 2] + ( 3c) complexes. The presence of the η 2-H 2 ligand is indicated by short T 1 min values and J HD measurements of the partially deuterated derivatives. Aquo [RuTp(H 2O)L(PPh 3)]BPh 4 ( 4), carbonyl [RuTp(CO)L(PPh 3)]BPh 4 ( 5), and nitrile [RuTp(CH 3CN)L(PPh 3)]BPh 4 ( 6) derivatives [L = P(OEt) 3] were prepared by substituting H 2 in the η 2-H 2 derivatives 3. Vinylidene [RuTp{ C C(H)R}L(PPh 3)]BPh 4 ( 7, 8) (R = Ph, t Bu) and allenylidene [RuTp( C C CR1R2)L(PPh 3)]BPh 4 ( 9– 11) complexes (R1 = R2 = Ph, R1 = Ph R2 = Me) were also prepared by allowing dihydrogen complexes 3 to react with the appropriate HC CR and HC CC(OH)R1R2 alkynes. Deprotonation of vinylidene complexes 7, 8 with NEt 3 was studied and led to acetylide Ru(C CR)TpL(PPh 3) ( 12, 13) derivatives. The trichlorostannyl Ru(SnCl 3)TpL(PPh 3) ( 14) compound was also prepared by allowing the chloro complex RuClTpL(PPh 3) to react with SnCl 2 · 2H 2O in CH 2Cl 2.

The hydroxyl radical reaction rate constant and products of 3,5‐dimethyl‐1‐hexyn‐3‐ol

AbstractA bimolecular rate constant,kDHO, of (29 ± 9) × 10−12 cm3 molecule−1 s−1 was measured using the relative rate technique for the reaction of the hydroxyl radical (OH) with 3,5‐dimethyl‐1‐hexyn‐3‐ol (DHO, HCCC(OH)(CH3)CH2CH(CH3)2) at (297 ± 3) K and 1 atm total pressure. To more clearly define DHO's indoor environment degradation mechanism, the products of the DHO + OH reaction were also investigated. The positively identified DHO/OH reaction products were acetone ((CH3)2CO), 3‐butyne‐2‐one (3B2O, HCCC(O)(CH3)), 2‐methyl‐propanal (2MP, H(O)CCH(CH3)2), 4‐methyl‐2‐pentanone (MIBK, CH3C(O)CH2CH(CH3)2), ethanedial (GLY, HC(O)C(O)H), 2‐oxopropanal (MGLY, CH3C(O)C(O)H), and 2,3‐butanedione (23BD, CH3C(O)C(O)CH3). The yields of 3B2O and MIBK from the DHO/OH reaction were (8.4 ± 0.3) and (26 ± 2)%, respectively. The use of derivatizing agents O‐(2,3,4,5,6‐pentalfluorobenzyl)hydroxylamine (PFBHA) and N,O‐bis(trimethylsilyl)trifluoroacetamide (BSTFA) clearly indicated that several other reaction products were formed. The elucidation of these other reaction products was facilitated by mass spectrometry of the derivatized reaction products coupled with plausible DHO/OH reaction mechanisms based on previously published volatile organic compound/OH gas‐phase reaction mechanisms. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 534–544, 2004

Synthesis, structures and some reactions of Ru(C [tbnd]CC [tbnd]CFc)(PP)Cp (PP = dppm, dppe) and related compounds

The compounds Ru(C CC CFc)(PP)Cp [PP = dppe ( 1), dppm ( 2)], have been obtained from reactions between RuCl(PP)Cp and FcC CC CSiMe 3 in the presence of KF ( 1) or HC CC CFc and K[PF 6] ( 2), both with added dbu. The dppe complex reacts with Co 2(CO) 6(L 2) [L 2 = (CO) 2, dppm] to give 3, 4 in which the Co 2(CO) 4(L 2) group is attached to the outer C C triple bond. The PPh 3 analogue of 3 ( 5) has also been characterised. In contrast, tetracyanoethene reacts to give two isomeric complexes 6 and 7, in which the cyano-olefin has added to either C C triple bond. The reaction of RuCl(dppe)Cp with HC CC CFc, carried out in a thf/NEt 3 mixture in the presence of Na[BPh 4], gave [Ru{C CC(NEt 3) CHFc}(dppe)Cp]BPh 4 ( 8), probably formed by addition of the amine to an (unobserved) intermediate butatrienylidene [Ru( C C C CHFc)(dppe)Cp] +. The reaction of I 2 with 8 proceeds via an unusual migration of the alkynyl group to the Cp ring to give [RuI(dppe){η-C 5H 4C CC(NEt 3) CHFc}]I 3 ( 9). Single-crystal X-ray structural determinations of 1, 2 and 4– 9 are reported.

Activation of alkynes by {[Cp ∗Ru(CO)(PMe iPr 2)] +}: X-ray crystal structures of [formula omitted] and [formula omitted

The complex [ Cp ∗ Ru { OCMe 2 } ( CO ) ( PMe i Pr 2 ) ] [ BAr 4 ′ ] ( 2 , Ar 4 ′ = 3 , 5 - C 6 H 3 ( CF 3 ) 2 ) reacts with HC CPh at −40 °C in CD 2Cl 2 furnishing the π-alkyne adduct [ Cp ∗ Ru ( η 2 - HC CPh ) ( CO ) ( PMe i Pr 2 ) ] [ BAr 4 ′ ] ( 3), which rearranges to the vinylidene complex [ Cp ∗ Ru C CHPh ( CO ) ( PMe i Pr 2 ) ] [ BAr 4 ′ ] ( 4a) when the temperature is raised to 25 °C. [ Cp ∗ Ru C CHR ( CO ) ( PMe i Pr 2 ) ] [ BAr 4 ′ ] (R = Ph 4a, t Bu 4b, H 4c) were obtained by reaction of [Cp ∗RuCl(CO)(PMe i Pr 2)] ( 1) with NaBAr 4 ′ and alkyne in fluorobenzene. Addition of water to the vinylidene complexes leads to the dicarbonyl [ Cp ∗ Ru ( CO ) 2 ( PMe i Pr 2 ) ] [ BAr 4 ′ ] ( 5), whereas deprotonation yields neutral σ-alkynyl complexes [Cp ∗Ru(C CR)(CO)(PMe i Pr 2)] (R = t Bu 6b, H 6c). The allenylidene complex [ Cp ∗ Ru C C CPh 2 ( CO ) ( PMe i Pr 2 ) ] [ BAr 4 ′ ] ( 7) was prepared by reaction of 1 with HC CC(OH)Ph 2 and NaBAr 4 ′ in fluorobenzene.

Preparation and characterization of tricobalt methylidyne clusters: X‐ray crystal structures of [Co3(CO)9(µ3‐CR)] (R = CH2CH3, CH2C(O)NH2, CH2C(O)CH3) and [Co3(CO)7(µ‐P,P‐PPh2CH2PPh2) (µ3‐CCH2C6H4NH2)

AbstractA small quantity of the tricobalt methylidyne cluster [Co3(CO)9(µ3‐CCH2CH3)] (2) was obtained, along with the major product, [{[Co2(CO)6(µ‐HCC)]CH2NH}2CO] (1), from the reaction of HCCCH2NH2 with Co2(CO)8 in tetrahydrofuran at 45 °C for 5 h. The crystal structure of 2 showed that the amino group was unexpectedly detached from the propargylamine. The reactions of two related amines, HCCC6H4NH2 and HCCC(O)NH2, with Co2(CO)8 gave two tricobalt methylidyne clusters, [Co3(CO)9(µ3‐CCH2C6H4NH2)] (5) and [Co3(CO)9(µ3‐CCH2C(O)NH2)] (7), respectively. Further reaction of 5 with bis(diphenylphosphino)methane (DPPM) resulted in the formation of the DPPM‐bridged tricobalt methylidyne cluster [Co3(CO)7(µ‐P,P‐PPh2CH2PPh2)(µ3‐CCH2C6H4NH2)] (6). Similar procedures were followed for the reaction of HCCC(O)CH3 with Co2(CO)8; two compounds, [Co3(CO)9(µ3‐CCH2C(O)CH3)] (8) and [Co2(CO)6(µ2‐η2‐HCCC(O)CH3)] (9), were obtained. All these compounds were characterized by spectroscopic means; the crystal structures of 2, 5, 6, and 7 were also determined. Copyright © 2003 John Wiley &amp; Sons, Ltd.

Regioselective addition of secondary phosphine oxides to 3-(trialkylsilyl)- and 3-(trialkylgermyl)-2-propynals

3-(Trialkylsilyl)- and 3-(trialkylgermyl)-2-propynals as well as 2-propynal react with secondary phosphine oxides by carbonyl group under mild conditions (−10 to 22 °C) to give corresponding tertiary phosphine oxides with acetylenic and hydroxyl moieties in quantitative yield. The reactivity of the aldehydes in this reaction drops in the following order: HCCC(O)H>Me 3SiCCC(O)H>Et 3GeCCC(O)H.

Closing the gap between MC3 and MC5 metallacumulenes: the chemistry of the first structurally characterized transition-metal complex with M=C=C=C=CR2 as the molecular unit.

The reactions of the dihydrido compound [IrH2Cl(PiPr3)2] (3) with HC identical to CC(O)CHPh2 and HC identical to CC(OAc)=CPh2 lead to the formation of alkynyl-(hydrido)iridium(III) and vinylideneiridium(I) complexes 4-7 which, however, are not suitable precursors for the target molecule trans-[IrCl(=C=C=C=CPh2)-(PiPr3)2] (8). Compound 8 has been prepared in 77% yield from 3 and the vinyl triflate HC identical to CC(OTf)=CPh2 in the presence of NEt3. Treatment of 8 with CF3CO2H affords the vinylvinylidene complex trans-[IrCl(=C=CHC(O2C-CF3)=CPh2)(PiPr3)2] (10) by addition of the electrophile to the C beta-C gamma bond of the MC4 chain. In contrast, the reaction of 8 with HCl yields the five-coordinate butadienyliridium(III) compound [IrCl2-(eta 1-(Z)-CH=CHC(Cl)=CPh2)(PiPr3)2] (11). Salt metathesis of 8 with KI, KOH, and NaN3 leads to the formation of the substitution products trans-[IrX-(=C=C=C=CPh2)(PiPr3)2] (12-14) of which the hydroxo derivative 13 reacts with phenol to give trans-[Ir(OPh)(=C=C=C=CPh2)(PiPr3)2] (15). From 13 and methanol, the octahedral dihydridoiridium(III) complex [IrH2(CH=C=C=CPh2)(CO)(PiPr3)2] (16) is formed by fragmentation of the alcohol. In the presence of CO, both the methyl compound trans-[Ir(CH3)(=C=C=C=CPh2)-(PiPr3)2] (17) (generated from 8 and CH3Li) and the azido complex 14 (X=N3) undergo migratory insertion reactions to yield the four-coordinate iridium(I) carbonyls trans-[Ir(C(C identical to CCH3)=CPh2)(CO)(PiPr3)2] (18) and trans-[Ir(C identical to CC(N3)=CPh2)(CO)(PiPr3)2] (19), respectively. Compound 19 rearranges slowly to the thermodynamically more stable isomer trans-[Ir(C(N3)=C=C=CPh2)(CO)(PiPr3)2] (20). The molecular structures of 8 and 18 have been determined crystallographically.

Ruthenium cluster carbonyls containing ligands derived from ferrocenylalkynes

Reactions of FcCCH ( a), HCCCCFc ( b) and FcCCCCFc ( c) with Ru 3(CO) 10(NCMe) 2 (all) and Ru 3(μ-dppm)(CO) 10 ( b and c only) are described. Among the products, the complexes Ru 3(μ 3-RC 2R′)(μ-CO)(CO) 9 (R=H, R′=Fc 1, CCFc 2; R=R′=Fc 5), Ru 3(μ-H)(μ 3-C 2CCFc)(μ-dppm)(CO) 7 3, Ru 3(μ 3-FcC 2CCFc)(μ-dppm)(μ-CO)(CO) 7 6 and Ru 3{μ 3-C 4Fc 2(CCFc) 2}(μ-dppm)(μ-CO)(CO) 5 7 were characterised, including single-crystal structure determinations for 1, 3, 5 and 7; that of 7 did not differ significantly from an earlier study of a mixed CH 2Cl 2–C 6H 6 solvate.