Cyanosilylation Reaction Research Articles

2D Hybrid Architectures Constructed from Two Kinds of Polyoxovanadates as Efficient Heterogeneous Catalysts for Cyanosilylation and Knoevenagel Condensation

The design of heterogeneous catalysts for highly efficient catalysis for cyanosilylation reactions and Knoevenagel condensations is greatly significant, due to the important application of their products in industry. Herein, five hybrid compounds constructed from two types of polyoxovanadates, [MV12O38]12- (M = Ni, Mn) and [V10O28]6-, were successfully synthesized as heterogeneous catalysts for both reactions, which are {(dpdo)[Ln2(H2O)9(dpdo)][Ln(H2O)5]2[Ln(H2O)4]2[V10O28][NiV12O38]·nH2O} (1, Ln = La, n = 23; 2, Ln = Ce, n = 27; 3, Ln = Pr, n = 27; dpdo = 4,4'-bipyridine N,N'-dioxide) and {(dpdo)[Ln2(H2O)9(dpdo)][Ln(H2O)5]2[Ln(H2O)4]2[V10O28][MnV12O38]·27H2O} (4, Ln = La; 5, Ln = Pr). These compounds were characterized by IR spectroscopy, elemental analysis, TG analysis and X-ray diffraction (single crystal and powder) etc. Compounds 1-5 have similar 2D hybrid structures, in which isopolyvanadate [V10O28]6- and heteropolyvanadate [MV12O38]12- are linked together by hydrated Ln3+ cations and Ln-dpdo coordination complexes. Polyoxovanadates [V10O28]6- and [MV12O38]12- both originate from the transformation of the [MV13O38]7- raw material. This kind of extended structure containing isopolyvanadate and heteropolyvanadate has never been reported hitherto. Because of the Lewis acidity of the Ln3+ cation and the Lewis basicity of the polyoxovanadates, all five compounds exhibit excellent catalytic performance in cyanosilylation and Knoevengel condensation reactions. Especially, compound 3, with a Pr3+ cation, displayed the best catalytic results. Furthermore, these catalysts exhibit a truly heterogeneous nature and good recyclability.

Porous Cu(II)-organic framework for solvent-free cyanosilylation and anti-gastric cancer activity by inducing cell apoptosis

A novel metal–organic framework (MOF) containing Cu(II) ions with the chemical formula of {[Cu(L)2(H2O)2](DMF)3}n (1) was successfully prepared by solvothermal reaction method using metal Cu2+ ions as nodes and bifunctional ligand 3-(1H-tetrazol-5-yl)pyridine as organic linker. The activated MOF 1 (1a) could be utilized as catalyst for solvent-free heterogeneous catalytic cyanosilylation reaction because of its open Cu(II) metal positions, and its large amount of nitrogen atoms could be applied as Lewis basic positions. Thus, its catalytic mechanism was also investigated in detail. The specific mechanism was discussed, and its inhibition of the viability of MGC-803 gastric cancer cells was assessed. First, cell counting kit-8 assay was performed to determine the anti-cancer effect of compound 1a against the viability of MGC-803 cells. Then, Annexin V-fluorescein isothiocyanate/propidium iodide method was implemented to determine the percentage of apoptotic MGC-803 cells. Finally, the accumulation of reactive oxygen species in MGC-803 cells treated with the compound was determined via dichloro-dihydro-fluorescein diacetate assay.

Manganese-organic framework assembled by 5-((4′-(tetrazol-5″-yl)benzyl)oxy)isophthalic acid: A solvent-free catalyst for the formation of carbon–carbon bond

A new three-dimensional manganese-based metal–organic framework Mn4L2(HL)(H2O)5, (1), based on semi-rigid 5-((4′-(tetrazol-5′’-yl)benzyl)oxy)isophthalic acid ligand (H3L) have been prepared and characterized under solvothermal condition. In the structure of 1, trinuclear Mn3O13N2 units are linked each other by sharing vertex and edge to form left- and right- hand helical O-Mn-O chains along b axis, then adjacent left and right handed helical chains are interconnected by L3− and HL2− ligands to generate a 2D layer and L3− ligands with mode II connect the neighboring layers to form a 3D network. 1 shows high stability under different pH conditions and various organic solvents. After activation, 1 exhibits excellent catalytic properties for two typical CC bond reactions, cyanosilylation and Knoevenagel condensation reaction of aldehydes, under solvent-free conditions at room temperature.

RETRACTED ARTICLE: New Co(II)-organic framework for cyanosilylation reactions and treatment effect against esophageal cancer by inhibiting cancer cell viability, migration, and invasion

We, the Editors and Publisher of the Journal of Coordination Chemistry, have retracted the following article: Hui Zan, Yongdong Huang, Changgao Wang, Zihao Liu, Nan Du & Xiaoman Wang. New Co(II)-organic framework for cyanosilylation reactions and treatment effect against esophageal cancer by inhibiting cancer cell viability, migration, and invasion, Journal of Coordination Chemistry; 2020, VOL. 73, NO. 9, 1464–1477. DOI: 10.1080/00958972.2020.1788001 Since publication, concerns have been raised about the integrity of the data in the article. When approached for an explanation, the authors have been unable to address the concerns raised and have not been able to provide sufficient supporting information. As verifying the validity of published work is core to the integrity of the scholarly record, we are therefore retracting the article. The corresponding author listed in this publication has been informed. The authors do not agree with the retraction. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’.

RETRACTED: A microporous roust La(III)-organic framework for cyanosilylation reactions and treatment effect on tuberculosis by activating the PI3K-AKT signaling pathway in immune cells

Abstract A novel metal–organic framework (MOF) based on La(III) ions as the metal nodes with the formula of {[LaL(H2O)2]·H2O}n (1) was prepared under the hydrothermal conditions by using 1-(4-carboxybenzyl)-1H-pyrazole-3,5-dicarboxylic acid (H3L) as the three connected ligand. Complex 1 shows excellent water stabilities as well as solvent-free conditions, and reveals microporous nature as established via the CO2 sorption at 195 K. The resulting activated 1a shows good heterogeneous catalytic activity for the cyanosilylation of the aromatic aldehydes, which could be reused for at least four times without losing the framework integrality. Furthermore, anti-bacterial activity of the compound was deep studied within the research. Firstly, the RT-PCR was utilized to determine pi3k and akt relative expression in macrophages after tuberculosis (TB) infection and compound treatment. And the ELISA detection was enrolled for IFN-γ and TNF-α detection. Next, the production of active nitrogen mediator (RNIs) was measured by the RNIs detection kit. Finally, compound protective function in vivo was assessed within the TB infected mice model, the bacterial colony numbers in the lung tissue was determined by diluting ager plate method, the pathological injury of lung was observed by HE staining. In this research, we aim to reveal a new candidate for the TB infection treatment.

Dialkyl imidazolium acetate ionosilica as efficient and recyclable organocatalyst for cyanosilylation reactions of ketones

We report new heterogeneous organocatalyst based on silica hybrid supported N-heterocyclic carbene (NHC-) species. The organocatalyst is formed from an imidazolium iodide based ionosilica material, followed by iodide/acetate anion exchange. The imidazolium acetate generates the organocatalytic carbene via partial deprotonation of the imidazolium ring in situ. As monitored via EDX, solid state NMR and ion chromatography measurements, the iodide/acetate exchange involving the imidazolium ionosilica material took place only in small extent. Despite the fact that the exchanged material contains only a very small amount of acetate, we observed good catalytic activity and recyclability in cyanosilylation reactions of ketones with trimethylsilyl cyanide. The versatility of the catalyst was highlighted via reaction with several substrates, yielding the corresponding cyanohydrins in good yields. In recycling experiments, the material showed decreasing catalytic activity starting from the third reaction cycle, but high catalytic activity can be regenerated via another acetate treatment. Our work is important as it highlights the possibility to combine carbene chemistry and silica, which are antagonistic at a first glance. We show that imidazolium acetate based ionosilicas are therefore heterogeneous ‘proto-carbenes’, and that there is no need to form strongly basic silica supported NHCs to obtain heterogeneous NHC-organocatalysts. This work therefore opens the route towards heterogeneous and re-usable NHC-organocatalysts from supported ionic liquid imidazolium acetates.

Carbonyl-Stabilized Phosphorus Ylide as an Organocatalyst for Cyanosilylation Reactions Using TMSCN

We report carbonyl-stabilized phosphorus ylides as general and efficient catalysts for the cyanosilylation of ketones. The N,N-diethylacetamide derived phosphorane is identified as an extremely efficient catalyst for the cyanosilylation of dialkyl ketones, alkyl aryl ketones, diaryl ketones, and α,β-unsaturated enones with catalyst loading down to 0.005 mol %, the lowest ever known for ketone cyanosilylation. Aldehydes, aldimines, and ketimines are also viable substrates. By NMR and React IR analysis, as well as electrical conductivity experiments, it is proposed that the phosphorane acts as a Lewis base in order to mediate the reaction via the desilylative nucleophilic activation of TMSCN.

Multinuclear Zn(II)-arylhydrazone complexes as catalysts for cyanosilylation of aldehydes

Three known multinuclear Zn(II)-arylhydrazone complexes, [Zn{(CH3)2SO}(H2O)(L1)] (1), [Zn2(CH3OH)2(μ-L2)2] (2) and [Zn4(μ-OH)2(1κO:2κO-HL3)4(κO-HL3)2(H2O)4] (3) were prepared upon reaction of ZnCl2 or Zn(CH3COO)2·2H2O with 3-(2-(2-hydroxy-4-nitrophenyl) hydrazineylidene) pentane-2,4-dione (H2L1), 3-(2-(2-hydroxyphenyl)hydrazineylidene)pentane-2,4-dione (H2L2) and 2-(2-(2,4-dioxopentan-3-ylidene)hydrazineyl)benzoic acid (H2L3), respectively, in methanol solution. Compounds 1–3 were tested as catalysts for the cyanosilylation reaction of a diversity of both aliphatic and aromatic aldehydes with trimethylsilyl cyanide yielding the corresponding cyanohydrin trimethylsilyl ethers in high yields (72–98%) in methanol and at room temperature.

RETRACTED: Porous Co-MOF for cyanosilylation reaction and protective effect in child bronchial pneumonia by reducing the inflammatory response and IL-12 production in immune cells

Abstract A new porous metal–organic framework (MOF) with the chemical formula of [Co2(FDDI)(H2O)3](DMA)4 (1, H4FDDI = 5,5′-(9H-fluorene-2,7-diyl) showing the ttd-type topological structure has been prepared by solvothermal method. The structural determination results reveal that the coordinated water molecule in the center of Co(II) has been able to be removed by activating 1 at 120 °C, resulting in a porous skeleton arranged by unsaturated Lewis acid Co(II) ions. That activated 1 has demonstrated a nice catalytic activity for the cyanosilylation of acetaldehydes using the CH2Cl2 as the solvent under mild conditions. Furthermore, the ELISA assay was performed to measure the content of IL-12 in macrophages after compound treatment. And the RT-PCR was conducted to reveal the activation of JAK/STAT signaling pathway after compound addition.

A new heterometallic MOF with 1D nano-sized channels for cyanosilylation reaction and prevention effect against arrhythmia by reducing the sympathetic excitability

In this work, by appealing to a heterometallic cluster approach, a new highly porous metal-organic framework (MOF) formulated as {(Me2NH2)[Ni3K2(TZIA)3(H2O)3]·(DMF)4}n (1) has been fabricated by a solvothermal reaction of a bifunctional organic ligand 5-(1 H-tetrazol-5-yl)isophthalic acid (H3TZIA) with the Ni(II) and K(I) salts in water and DMF mixed solvents. The resulting activated 1a has been explored in detail for BET analysis to probe its porosity. The removal of water molecule at the aim of generating 1a makes K+ ion become a heterogeneous catalyst of size-selective with high efficiency for solvent-free cyanosilylation of acetaldehyde under mild conditions. Furthermore, the prevention effect of the compound on the arrhythmia occurrences after anesthesia during operation was evaluated. The arrhythmia incidence and abnormal blood pressure was calculated and measured for the detection of compound prevention ability. Besides, the Norepinephrine (NE) and Adrenaline (A) released by the cardiomyocytes were measured by the ELISA kit.

Tunable morphology and the changeable catalytic property of layered scandium coordination polymer

Sc-CP 1, 1A, 1B and 1C with controllable morphologies were successfully synthesized by the conventional hydrothermal method and microwave (MW) assisted hydrothermal method. 1 was macroscopic, 1A was nano sized, while 1B and 1C were micron sized. Sc-CP 1 showed two-dimensional (2D) layered structure which was constructed from the connections of left- and right-hand helical chains. Catalytic experiments showed the catalytic performances of Sc-CP 1, 1A, 1B and 1C for the cyanosilylation reaction of aromatic aldehydes were dependent on the morphologies of the particles. Flower-ball-like 1C featuring a high concentration of Lewis acidic Sc(III) sites on its exposed external surfaces showed better catalytic activity than others, the best constant rate of which was 6.4 ​× ​10−3 min−1.

Lanthanide-Based Metal-Organic Frameworks Containing "V-Shaped" Tetracarboxylate Ligands: Synthesis, Crystal Structures, "Naked-Eye" Luminescent Detection, and Catalytic Properties.

Three lanthanide-based metal-organic frameworks, [Tb(HMDIA)(H2O)3]·H2O (Tb-MDIA), [Ho(HMDIA)(H2O)3]·(H2O)2 (Ho-MDIA), and [Nd(HMDIA)(H2O)3]·(H2O)2 (Nd-MDIA) from the same V-shaped ligand 5,5'-methylenediisophthalic acid (H4MDIA), were prepared by mixing Ln3+ and H4MDIA under solvothermal conditions. The crystal structures of the three complexes were determined by single-crystal X-ray diffraction. The different coordination modes of the organic ligands resulted in different framework structures among the three complexes. The luminescent properties of Ln-MDIA in the ultraviolet-visible region were also studied. Interestingly, the bright-green emitter Tb-MDIA showed high selectivity and sensitivity to allow the naked-eye visualization of Fe3+ ions and picric acid (PA) explosive, and both sensing mechanisms were revealed. Finally, Ho-MDIA and Nd-MDIA were shown to work as heterogeneous catalysts for the cyanosilylation reaction of aromatic aldehydes, and the catalysts could be recycled at least three times without any decrease in activity.

A Highly Porous Co-MOF for Cyanosilylation Reaction and Inhibition on P. gingivalis Growth and rgp and kgp Expression for Periodontal Treatment

A novel porous three-dimensional Co(II) organic framework of metal, [{Co2(TCPP)(H2O)}·DMF]n (1), (where H4TCPP = 2,3,5,6-tetrakis(4-carboxyphenyl)pyrazine) was synthesized under the solvent thermal condition, consisting of a H4TCPP ligand which is rigid and tetratopic. Intriguingly, the centers of Co(II) coordinated water molecules can be dislodged via activating 1 under 120 °C, resulting in a pores skeleton arranged by Lewis acidic Co(II) ions which are unsaturated. Activated 1 has great activity of catalysis for without solvent cyanosilylation of acetaldehydes under mild conditions. To develop the candidates for the periodontal diseases therapy, the inhibitory effect of the compound on the growth curves of Porphyromonas gingivalis was evaluated. Next, the RT-PCR detection of rgp and kgp was conducted to explore the effect of compound on the key gene expression.

A urea-containing metal-organic framework as a multifunctional heterogeneous hydrogen bond-donating catalyst

A urea-containing metal-organic framework (MOF) was synthesized from a V-shaped dicarboxylate ligand and Cu(II) ions. As the undesirable self-aggregation of the urea moiety has been prohibited in the framework, this MOF can act as a heterogeneous hydrogen bond-donating (HBD) catalyst, which accelerates the cyanosilylation reaction of aldehydes, the Henry reaction of aldehydes, and the methanolysis reaction of epoxides. It also displays a significantly enhanced catalytic activity when compared with its homogeneous urea counterpart and analogous MOF structures.

A New Co(II)-Based Metal–Organic Framework for Size-Selective Cyanosilylation Reaction and Anti-cancer Activity Against Lung Cancer Cell via Inducing Apoptosis

A novel metal–organic framework {[Co4(HL)4](DMF)3}n (1, DMF = N,N-dimethylformamide) based on Co(II) ion as the metal source has been successfully prepared under the solvothermal condition using a mixed-donor pyridyl–tricarboxylate ligand 5-(5-carboxypyridin-3-yl)isophthalic acid (denoted as H3L). X-ray analysis of single crystal shows that they have a 3D PtS-type networks with non-interpenetrating (4,4)-connections, and the Schlafli point symbol is {42·84}. The resulting activated 1a has been explored in details for Brunauer–Emmett–Teller (BET) analysis to probe its porosity. It is commendable that the activated 1a can be applied as multiphase catalyst for cyanidation of acetaldehyde without solvent under the mild conditions. Furthermore, we aimed to evaluate the inhibitory function of compound on the anti-viability ability on of cancer cell, which was proved by the Cell Counting Kit-8 (CCK-8) test. To further detect the anti-cancer mechanism of the compound, the reverse transcription-polymerase chain reaction (RT-PCR) detection of the blc-2, bax relative expression in NCI-H460 was also measured.

Retracted] A New Heterometallic MOF in Cyanosilylation Reaction, Treatment and Care Management Value in Stroke by Reducing Oxidative Stress Damage

Abstract By employment the heterometallic strategy, a new highly porous metal-organic framework {(Me2NH2)[Mn3K2(TZIA)3(H2O)3]·(DMF)4}n (1) was prepared via corresponding K(I)and Mn(II) salts and hetero-donor organic ligand 5-(1H-tetrazol-5-yl)isophthalic acid (H3TZIA) via solvothermal conditions in water and DMF mixed solvent. X-ray study of a single crystal shows that ionic K+ was immobilized on the surface of pores via trinuclear Mn2+–tetrazole coordination motif. The resulting activated 1a has been explored in detail by BET analysis to probe its porosity. The removal of water molecules in order to generate 1a makes it possible for K+ ions to be applied as an efficient and size-selective multiphase catalyst for cyanosilylation of acetaldehyde under the mild conditions without solvent. Furthermore, ELISA assay was performed to measure IL-18 and IL-1β level in hCMEC/D3 human brain microvascular endothelial cells after compound treatment. Besides, ROS detection and RT-PCR was performed to detect ROS production as well as the related gene expression. Next, the protective effect of the compound was evaluated in animal model in vivo.

Zirconium coordination polymers based on tartaric and malic acids as catalysts for cyanosilylation reactions

The synthesis of chiral materials is a great challenge. This work describes the synthesis of Zr-based coordination polymers composed of chiral ligands derived from natural products. L-tartaric acid, dibenzoyl-L-tartaric acid and L-malic acid were selected as ligands from the chiral pool. Their reaction with zirconium oxychloride gave rise to several materials that were characterized by different techniques, such as XRD, Raman spectroscopy, 13C MAS NMR, TGA and N2 adsorption/desorption isotherms. Significant structural and textural properties have been observed depending on the ligand, the synthesis procedure and the metal to ligand ratio. These polymers were used for the first time as catalysts in the cyanosilylation of benzaldehyde with trimethylsilyl cyanide and their activity was compared with that of UiO-66. Different reaction parameters and reusability were studied for this asymmetric reaction. Some of the reported materials were very active in this reaction and provided a remarkable enantioselectivity depending on the reaction conditions.

Bifunctional Gyroidal MOFs: Highly Efficient Lewis Base and Lewis Acid Catalysts.

A family of gyroidal metal-organic frameworks (STUs) composited with transition metal ions and bi-imidazolate ligands (BIm) were prepared and applied as both Lewis base and acid catalysts. Benefiting from the intrinsic basicity of the ligands and the Lewis acidic sites of the open metal centres, the STUs materials show excellent catalytic activities as Lewis base for the Knoevenagel condensation reaction between various aldehydes and malononitrile, and as Lewis acid for cyanosilylation reactions. Among these STUs, STU-4 (Ni(BIm)) shows the best catalytic efficiency (conversions >99 %) in both Knoevenagel condensation and cyanosilylation reactions under mild conditions, providing thus an advanced material for both Lewis base and Lewis acid catalysis.

RETRACTED ARTICLE: Three-Dimensional Ni(II)-MOF Containing an Asymmetric Pyridyl-Carboxylate Ligand: Catalytic Cyanosilylation of Aldehydes and Inhibits Human Promyelocytic Leukemia Cancer Cells

A new Ni(II)-based metal–organic framework with the chemical formula of (Me2NH2)[Ni3(L)2(μ3-OH)(H2O)]·2DMF (1) have been designed and synthesized by the reaction of 3-phenylpyridine polycarboxylic (H3L) ligands and Ni(NO3)2·6H2O in a mixed solvent of DMF and water under the solvothermal conditions. The resulting solvent-free 1a was found to be catalytically active for the cyanosilylation reaction of aromatic aldehydes with nitro substituent in varying positions in the presence of trimethylsilyl cyanide to afford cyanohydrin trimethylsilyl ethers in a shape and size selective manner. The as-prepared 1 did not exhibit catalytic activities for the same reaction. Based on the experimental results, a possible catalytic mechanism has also been proposed. We next examined the cell viability with CCK-8 assay and the cell proliferation with plate colony formation assay. Both experiments suggested the inhibitory effect of compound 1a on human promyelocytic leukemia cancer HL-60 cells. For the mechanism exploration, the ROS content in HL-60 cancer cells was measured with detection kit, results also indicated the compound 1a increased the level of ROS in HL-60 cells, which may the reason of the compound’s anti-cancer activity.

The Hydrosilylation and Cyanosilylation of Ketones Catalyzed using Metal Borohydrides.

The hydrosilylation reaction of carbonyl compounds has emerged as a powerful method in organic synthesis. The catalytic hydrosilylation of ketones is a valuable transformation because it generates protected cyanosilylation reaction of carbonyl compounds is an efficient procedure for the synthesis of silylated cyanohydrins, which are readily converted into useful functionalized compounds, such as cyanohydrins, α-hydroxy acids, β-amino alcohols and other biologically active compounds. A facile, economic and efficient method has been developed for the hydrosilylation and cyanosilylation of ketones using metal borohydrides. A series of silylated ethers and silylated cyanohydrins can be isolated via direct distillation. The catalytic properties of a range of metal borohydrides in the hydrosilylation reaction of acetophenone with diphenylsilane were investigated. The relative catalytic activity of the borohydride catalyst studied was as follows: (CH3)4NBH4> (PhCH2)(CH3)3NBH4> (CH2CH3)4NBH4> (CH3CH2CH2CH3)4NBH4> NaBH4> KBH4> LiBH4. The cyanosilylation of acetophenone using trimethylsilyl cyanide (TMSCN) in the presence of NaBH4 occurred under similar reaction conditions. An excellent reaction rate and high conversion were obtained. The metal borohydride-catalyzed hydrosilylation alcohols in one step. The and cyanosilylation of ketones could be carried out smoothly under mild reaction conditions. Among the metal borohydrides studied, an excellent reaction rate and high conversion were obtained using NaBH4, NaBH (CH2CH3)3 or (alkyl)4 NBH4 as the reaction catalyst.