Supported Nickel Nanoparticles as Catalyst in Direct sp C-H Alkylation of 9H-Fluorene Using Alcohols as Alkylating Agent.

Herein, we report an inexpensive first-row transition metal Ni heterogeneous catalytic system for the C -mono alkylation of fluorene using alcohols as alkylating agents via borrowing hydrogen strategy. The catalytic protocol displayed versatility with high yields of the desired products using various types of primary alcohols, including aryl/hetero aryl methanols, and aliphatic alcohols as alkylating agents. The catalyst Ni NPs@N-C was synthesized via high-temperature pyrolysis strategy, using ZIF-8 as the sacrificial template.

Bootstrap tests for simultaneous monotone ordering of effects in a two-way ANOVA.

In a two-way additive analysis of variance (ANOVA) model, we consider the problem of testing for homogeneity of both row and column effects against their simultaneous ordering. The error variances are assumed to be heterogeneous with unbalanced samples in each cell. Two simultaneous test procedures are developed-the first one using the likelihood ratio test (LRT) statistics of two independent hypotheses and another based on the consecutive pairwise differences of estimators of effects.

Multicomponent synthesis acceptorless alcohol dehydrogenation: an easy access to tri-substituted pyridines.

Herein, we report palladium supported on a hydroxyapatite catalyst for synthesizing tri-substituted pyridines using ammonium acetate as the nitrogen source acceptorless alcohol dehydrogenation strategy. The strategy offers a broad substrate scope using inexpensive and readily available alcohols as the starting material. The catalyst was prepared using a simple method and analyzed by several techniques, including FE-SEM, EDS, HR-TEM, BET, XRD, FT-IR, UV-visible spectroscopy, and XPS, demonstrating the anchoring of Pd nanoparticles on hydroxyapatite in the zero oxidation state.

-Alkylation of dithiocarbamates a hydrogen borrowing reaction strategy using alcohols as alkylating agents.

Herein, we report an operationally simple, environmentally benign and scalable approach towards the synthesis of -benzyl/alkyl dithiocarbamates a hydrogen borrowing reaction between alcohols and dithiocarbamate anions catalyzed using a hydroxyapatite-supported copper nano-catalyst. This strategy has a broad substrate scope and offers high yields of products using inexpensive and readily available alcohols as starting materials. The catalyst was prepared by easy and straightforward methods and analyzed by several analytical techniques, , FESEM, HR-TEM, BET, XRD, EDS, and XPS, demonstrating the anchoring of Cu nanoparticles on hydroxyapatite in the zero oxidation state.

Single site silica supported tetramethyl niobium by the SOMC strategy: synthesis, characterization and structure-activity relationship in the ethylene oligomerization reaction.

A silica supported tetramethyl niobium complex [([triple bond, length as m-dash]SiO)NbMe] 2 has been isolated by the surface alkylation of [([triple bond, length as m-dash]SiO-)NbClMe] 1 with dimethyl zinc in pentane. 1 can be easily synthesized by grafting NbClMe onto the surface of partially dehydroxylated silica by the SOMC strategy. Precise structural analysis was carried out using FTIR, advanced solid state NMR, elemental analysis and mass balance techniques (gas quantification after treating 2 with degassed water).

Unearthing a Well-Defined Highly Active Bimetallic W/Ti Precatalyst Anchored on a Single Silica Surface for Metathesis of Propane.

Two compatible organometallic complexes, W(Me) (1) and TiNp (2), were successively anchored on a highly dehydroxylated single silica support (SiO) to synthesize the well-defined bimetallic precatalyst [(≡Si-O-)W(Me)(≡Si-O-)Ti(Np)] (4). Precatalyst 4 was characterized at the molecular level using advanced surface organometallic chemistry (SOMC) characterization techniques. The strong autocorrelation observed between methyl of W and Ti in H-H multiple-quantum NMR spectra demonstrates that W and Ti species are in close proximity to each other.

A New Class of Atomically Precise, Hydride-Rich Silver Nanoclusters Co-Protected by Phosphines.

Thiols and phosphines are the most widely used organic ligands to attain atomically precise metal nanoclusters (NCs). Here, we used simple hydrides (e.g.

Synthesis and characterization of a homogeneous and silica supported homoleptic cationic tungsten(vi) methyl complex: application in olefin metathesis.

A method for the synthesis of a homogeneous cationic tungsten(vi)pentamethyl complex [(WMe)(CF)BMe] from neutral tungstenhexamethyl (WMe) and a silica supported cationic tungstentetramethyl complex [([triple bond, length as m-dash]Si-O-)WMe (CF)BMe] from a neutral silica supported tungstenpentamethyl complex [([triple bond, length as m-dash]Si-O-)WMe] is described. In both cases a direct demethylation using the B(CF) reagent was used. The aforesaid complexes were characterized by liquid or solid state NMR spectroscopy.

Synergy between Two Metal Catalysts: A Highly Active Silica-Supported Bimetallic W/Zr Catalyst for Metathesis of n-Decane.

A well-defined, silica-supported bimetallic precatalyst [≡Si-O-W(Me)5≡Si-O-Zr(Np)3] (4) has been synthesized for the first time by successively grafting two organometallic complexes [W(Me)6 (1) followed by ZrNp4 (2)] on a single silica support. Surprisingly, multiple-quantum NMR characterization demonstrates that W and Zr species are in close proximity to each other. Hydrogenation of this bimetallic catalyst at room temperature showed the easy formation of zirconium hydride, probably facilitated by tungsten hydride which was formed at this temperature.

Effect of support on metathesis of n-decane: drastic improvement in alkane metathesis with WMe5 linked to silica-alumina.

[WMe6 ] (1) supported on the surface of SiO2 -Al2 O3(500) (2) has been extensively characterized by solid-state NMR spectroscopy, elemental analysis, and gas quantification, which clearly reveal the formation of a mixture of monopodal and bipodal species with the migration of methyl from W to Al. The supported species SiO2 -Al2 O3(500) (2) transformed at 120 °C into two types of carbynic centers, one of which is cationic and the other neutral. These species are very efficient for the metathesis of n-decane.

ZnO-supported Pd nanoparticle-catalyzed ligand- and additive-free cyanation of unactivated aryl halides using K4[Fe(CN)6].

The use of a new ZnO-supported palladium(0) nanoparticle catalyst for the cyanation of aryl halides using a relatively benign cyanide source, K4[Fe(CN)6], is described. This catalyst has been applied for the efficient cyanation of a variety of functionalized aryl bromides and activated aryl chlorides. This process circumvents the need for an additive and a ligand for the reaction and offers the advantages of high product yields, low catalyst loading (0.

WMe6 tamed by silica: ≡Si-O-WMe5 as an efficient, well-defined species for alkane metathesis, leading to the observation of a supported W-methyl/methylidyne species.

The synthesis and full characterization of a well-defined silica-supported ≡Si-O-W(Me)5 species is reported. Under an inert atmosphere, it is a stable material at moderate temperature, whereas the homoleptic parent complex decomposes above -20 °C, demonstrating the stabilizing effect of immobilization of the molecular complex. Above 70 °C the grafted complex converts into the two methylidyne surface complexes [(≡SiO-)W(≡CH)Me2] and [(≡SiO-)2W(≡CH)Me].

Highly selective reduction of nitroarenes by iron(0) nanoparticles in water.

Highly selective reduction of nitroarenes has been achieved using iron metal nanoparticles in water at room temperature. A wide spectrum of reducible functionalities remained inert under the reaction conditions. During the reaction a change in shape of Fe nanoparticles was observed.

Copper nanoparticle-catalyzed carbon-carbon and carbon-heteroatom bond formation with a greener perspective.

The carbon-carbon and carbon-heteroatom bond formations constitute the backbone of organic synthesis and have been widely used in the synthesis of natural products and useful compounds. Because of growing environmental concern, more attention has been focussed on the development of greener methods. Copper is environment-friendly and comparatively inexpensive.

Using more environmentally friendly solvents and benign catalysts in performing conventional organic reactions.

The protection of the environment from toxic materials is an area of increasing concern. This review describes selected chemical processes that use more environmentally friendly solvents and less toxic catalysts. For example, water, ionic liquids and supercritical fluids have demonstrated promising activity as alternative benign reaction media for various reactions.

Palladium(0) nanoparticle catalyzed cross-coupling of allyl acetates and aryl and vinyl siloxanes.

The cross-coupling of allyl acetates and aryl and vinyl siloxanes proceeds readily by the catalysis of in situ generated palladium(0) nanoparticles. The reactions are stereoselective, and (E)-coupling products are obtained both from cis and trans allyl acetates. The coupling with vinyl siloxanes provides a novel protocol for the synthesis of 1,4-pentadienes.