Cu(II) Coordination Polymers for the Selective Oxidation of Biomass-Derived Veratryl Alcohol in Green Solvents: A Sustainable Catalytic Approach.

Four air-stable one-dimensional copper(II) coordination polymers (-) with azide linkers were synthesized using tridentate NNS and NNN ligands. Single-crystal X-ray diffraction (XRD) analysis confirmed the molecular structures of , , and . In the presence of TEMPO, all four coordination polymers demonstrated effective catalytic activity for the selective aerobic oxidation of veratryl alcohol, a biomass model compound, under base-free conditions.

Copper-catalyzed C(sp)-H alkylation of fluorene with primary and secondary alcohols using a borrowing hydrogen method.

Despite the limited success of copper-catalyzed alkylations, (NNS)CuCl proved to be an effective catalyst for the sp C-H alkylation of fluorene with alcohols. Various primary alcohols and challenging secondary alcohols were successfully used. The practical applicability of the method was effectively tested with several post-functionalization reactions.

Iron- and base-catalyzed (α)-alkylation and one-pot sequential alkylation-hydroxylation of oxindoles with secondary alcohols.

The utilization of economical and environmentally benign transition metals in crucial catalytic processes is pivotal for sustainable advancement in synthetic organic chemistry. Iron, as the most abundant transition metal in the Earth's crust, has gained significant attention for this purpose. A combination of FeCl (5 mol%) in the presence of phenanthroline (10 mol%) and NaOBu (1.

Chemical fixation of atmospheric CO in tricopper(II)-carbonato complexes with tetradentate N-donor ligands: reactive intermediates, probable mechanisms, and catalytic and magneto-structural studies.

In the present era, the fixation of atmospheric CO is of significant importance and plays a crucial role in maintaining the balance of carbon and energy flow within ecosystems. Generally, CO fixation is carried out by autotrophic organisms; however, the scientific community has paid substantial attention to execute this process in laboratory. In this report, we synthesized two carbonato-bridged trinuclear copper(II) complexes, [Cu(L1)(μ-CO)](ClO) (1) and [Cu(L2)(μ-CO)](ClO) (2) atmospheric fixation of CO starting with Cu(ClO)·6HO and easily accessible pyridine/pyrazine-based N donor Schiff base ligands L1 and L2, respectively.

Antibiotic induced adipose tissue browning in C57BL/6 mice: An association with the metabolic profile and the gut microbiota.

Aims: The use of antibiotics affects health. The gut microbial dysbiosis by antibiotics is thought to be an essential pathway to influence health. It is important to have optimized energy utilization, in which adipose tissues (AT) play crucial roles in maintaining health.

Cobalt-Catalyzed Chemodivergent Synthesis of Cyclic Amines and Lactams from Ketoacids and Anilines Using Hydrosilylation.

Here, commercially available Co(CO) was utilized as an efficient catalyst for chemodivergent synthesis of pyrrolidines and pyrrolidones from levulinic acid and aromatic amines under slightly different hydrosilylation conditions. 1.5 and 3 equiv of phenylsilane selectively yielded pyrrolidone and pyrrolidine, respectively.

Hydrosilylation of Terminal Alkynes Catalyzed by an Air-Stable Manganese-NHC Complex.

In recent years, catalysis with base metal manganese has received a significant amount of interest. Catalysis with manganese complexes having -heterocyclic carbenes (NHCs) is relatively underdeveloped in comparison to the extensively investigated manganese catalysts possessing pincer ligands (particularly phosphine-based ligands). Herein, we describe the synthesis of two imidazolium salts decorated with picolyl arms ( and ) as NHC precursors.

Copper(i)-catalyzed click chemistry in deep eutectic solvent for the syntheses of β-d-glucopyranosyltriazoles.

In the last two decades, click chemistry has progressed as a powerful tool in joining two different molecular units to generate fascinating structures with a widespread application in various branch of sciences. copper(i)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction, also known as click chemistry, has been extensively utilized as a versatile strategy for the rapid and selective formation of 1,4-disubstituted 1,2,3-triazoles. The successful use of CuAAC reaction for the preparation of biologically active triazole-attached carbohydrate-containing molecular architectures is an emerging area of glycoscience.

Cobalt catalyzed chemoselective reduction of nitroarenes: hydrosilylation under thermal and photochemical reaction conditions.

Commercially available Co(CO) was used as an effective catalyst for the hydrosilylation of nitroarenes under both thermal and photochemical conditions. A wide variety of nitroarenes with various functionalities were selectively reduced to aromatic amines. Syntheses of drug molecules expand the potential utility of this protocol.

Azide-Alkyne Cycloaddition Catalyzed by Copper(I) Coordination Polymers in PPM Levels Using Deep Eutectic Solvents as Reusable Reaction Media: A Waste-Minimized Sustainable Approach.

Two air-stable copper(I)-halide coordination polymers and with NNS and NNO ligand frameworks were synthesized and successfully utilized as efficient catalysts in an important organic reaction, namely, copper-catalyzed azide-alkyne cycloaddition, which is generally conducted in a mixture of water and organic solvents. The azide-alkyne "click" reaction was successfully conducted in pure water at r.t.

Nickel-Catalyzed α-Alkylation of Arylacetonitriles with Challenging Secondary Alcohols.

Nickel(II) complex was utilized as a sustainable catalyst for α-alkylation of arylacetonitriles with challenging secondary alcohols. Arylacetonitriles with a wide range of functional groups were tolerated, and various cyclic and acyclic secondary alcohols were utilized to yield a large number of α-alkylated products. The plausible mechanism involves the base-promoted activation of precatalyst to an active catalyst (dehydrochlorinated product) which activates the O-H and C-H bonds of the secondary alcohol in a dehydrogenative pathway.

Manganese-Catalyzed Chemoselective Hydrosilylation of Nitroarenes: Sustainable Route to Aromatic Amines.

Herein we report efficient catalytic hydrosilylations of nitroarenes to form the corresponding aromatic amines using a well-defined manganese(II)-NNO pincer complex with a low catalyst loading (1 mol %) under solvent-free conditions. This base-metal-catalyzed hydrosilylation is an easy and sustainable alternative to classical hydrogenation. A large variety of nitroarenes bearing various functionalities were selectively transformed into the corresponding aromatic amines in good yields.

Efficient α-Alkylation of Arylacetonitriles with Secondary Alcohols Catalyzed by a Phosphine-Free Air-Stable Iridium(III) Complex.

A well-defined and readily available air-stable dimeric iridium(III) complex catalyzed α-alkylation of arylacetonitriles using secondary alcohols with the liberation of water as the only byproduct is reported. The α-alkylations were efficiently performed at 120 °C under solvent-free conditions with very low (0.1-0.

Hydrosilylation of Esters Catalyzed by Bisphosphine Manganese(I) Complex: Selective Transformation of Esters to Alcohols.

Selective and efficient hydrosilylations of esters to alcohols by a well-defined manganese(I) complex with a commercially available bisphosphine ligand are described. These reactions are easy alternatives for stoichiometric hydride reduction or hydrogenation, and employing cheap, abundant, and nonprecious metal is attractive. The hydrosilylations were performed at 100 °C under solvent-free conditions with low catalyst loading.

Synthesis and oxidation of phosphine cations.

Cationic phosphines of the form [(L)PPh] are prepared by reaction of PhPCl with carbenes (L) including a chiral bis(oxazoline)-based carbene, a cyclic(alkyl)(amino) carbene (cAAC), and a 1,2,3-triazolium-derived carbene, affording the products, [(IBox-iPr)PPh][OSOCF] 1, [(cAAC)PPh][OSOCF] 2 and [((TripCHN(NMe)CPh)PPh)(AgCl)][Cl]3. Using PhPCl, the related dication [CH(NCHNDipp)PPh]4 was also prepared. Crystallographically-determined metric parameters and computational data indicate that these species are best described as cationic phosphines rather than phosphenium cations.

Catalytic Synthesis of N-Heterocycles via Direct C(sp)-H Amination Using an Air-Stable Iron(III) Species with a Redox-Active Ligand.

Coordination of FeCl to the redox-active pyridine-aminophenol ligand NNO in the presence of base and under aerobic conditions generates FeCl(NNO) (1), featuring high-spin Fe and an NNO radical ligand. The complex has an overall S = 2 spin state, as deduced from experimental and computational data. The ligand-centered radical couples antiferromagnetically with the Fe center.

Redox-Active-Ligand-Mediated Formation of an Acyclic Trinuclear Ruthenium Complex with Bridging Nitrido Ligands.

Coordination of a redox-active pyridine aminophenol ligand to Ru(II) followed by aerobic oxidation generates two diamagnetic Ru(III) species [1 a (cis) and 1 b (trans)] with ligand-centered radicals. The reaction of 1 a/1 b with excess NaN3 under inert atmosphere resulted in the formation of a rare bis(nitrido)-bridged trinuclear ruthenium complex with two nonlinear asymmetrical Ru-N-Ru fragments. The spontaneous reduction of the ligand centered radical in the parent 1 a/1 b supports the oxidation of a nitride (N(3-) ) to half an equivalent of N2 .

1,2,3-Triazolylidene ruthenium(II)-cyclometalated complexes and olefin selective hydrogenation catalysis.

Silver(i) 1,2,3-triazol-5-ylidenes [(RCH(2)C(2)N(2)(NMe)Ph)(2)Ag][AgCl(2)] (R = Ph 3a, C(6)H(2)iPr(3) 3b, C(6)H(2)Me(3) 3c) and [(PhCH(2)C(2)N(2)(NMe)R)(2)Ag][AgCl(2)] (R = C(6)H(4)Me 3d, C(6)H(4)CF(3) 3e) were synthesized and subsequently treated with RuHCl(PPh(3))(3) and RuHCl(H(2))(PCy(3))(2). The reaction 3a of with RuHCl(PPh(3))(3) gave RuHCl(PPh(3))(2)(PhCH(2)C(2)N(2)(NMe)Ph) (4a1) as the minor product and the cyclometalated complex RuCl(PPh(3))(2)(PhCH(2)C(2)N(2)(NMe)C(6)H(4)) (4a2) as the major product. However, similar reaction with 3b selectively formed the cyclometalated complex RuCl(PPh(3))(2)((C(6)H(2)iPr(3))CH(2)C(2)N(2)(NMe)C(6)H(4)) (4b2).

Half sandwich ruthenium(II) hydrides: hydrogenation of terminal, internal, cyclic and functionalized olefins.

Bis(1,2,3-triazolylidene) silver(I) complex 1a was reacted with [RuCl2(p-cymene)]2 to give the ruthenium complex [PhCH2N2(NMe)C2(C6H4CF3)]RuCl2(p-cymene) (2a) as major product in addition to the minor C(sp(2))-H activated product [PhCH2N2(NMe)C2(C6H3CF3)]RuCl(p-cymene) (2a'). Similar ruthenium complexes 2b, 2c, 2d and 2e with general formula RuCl2(p-cymene)(NHC) (NHC = MesCH2N2(NMe)C2Ph 2b, PhCH2N2(NMe)C2Ph 2c, TripCH2N2(NMe)C2Ph 2d, IMes 2e) were also synthesized. Subsequent reaction of Me3SiOSO2CF3 with 2a and 2b resulted in cationic ruthenium species [(PhCH2N2(NMe)C2(C6H4CF3))RuCl(p-cymene)][OSO2CF3] (3a) and [(MesCH2N2(NMe)C2Ph)RuCl(p-cymene)][OSO2CF3] (3b), respectively.

1,2,3-Triazolylidene ruthenium(II)(η⁶-arene) complexes: synthesis, metallation and reactivity.

Three bis(1,2,3-triazolylidene) silver(I) complexes were synthesized, and the ruthenium complexes ([RCH2N2(NMe)C2Ph)]RuCl2(p-cymene) (R = C6H2Me3 4a₁, C6H2iPr3 4b₁) were isolated as major products with the minor C(sp(2))-H activated products ([RCH2N2(NMe)C2C6H4)]RuCl(p-cymene) (R = C6H2Me3 4a₂, C6H2iPr3 4b₂). In the related case where R = Ph, the species ([PhCH2N2(NMe)C2Ph)]RuCl2(p-cymene) 4c₁ was obtained with two C(sp(2))-H activated products [PhCH2N2(NMe)C2C6H4)]RuCl(p-cymene) 4c₂ and [(C6H4)CH2N2(NMe)C2Ph)]RuCl(p-cymene) 4c₃ derived from metallation of the N and C-bound arene rings. Heating a solution of 4a₁ at 45 °C over three weeks resulted in a ruthenium(II)(1,2,3-triazolylidene) complex [(C6H2Me3)CH2N2(NMe)C2Ph)]RuCl2 5a, where the pendant mesityl group on the triazolylidene moiety displaced the p-cymene ligand.

Indium-bridged [1]ferrocenophanes.

Indium-bridged [1]ferrocenophanes ([1]FCPs) and [1.1]ferrocenophanes ([1.1]FCPs) were synthesized from dilithioferrocene species and indium dichlorides.

[1.1]Ferrocenophanes and bis(ferrocenyl) species with aluminum and gallium as bridging elements: synthesis, characterization, and electrochemical studies.

Salt-metathesis reactions between dilithioferrocene (Li(2)fc·2/3tmeda) and intramolecularly coordinated aluminum and gallium species RECl(2) [R = 5-Me(3)Si-2-(Me(2)NCH(2))C(6)H(3); E = Al (2a), Ga (2b); and R = (2-C(5)H(4)N)Me(2)SiCH(2); E = Al (3a), Ga (3b)] gave respective [1.1]ferrocenophanes ([1.1]FCPs).

Cyclic and linear polyferrocenes with silicon and tin as alternating bridges.

The synthesis and characterization of ferrocene-based oligomers that contained two different elements (Si and Sn) as alternating bridges is described for the first time. The salt-metathesis reaction of R(2) Si[(C(5) H(4) )Fe(C(5) H(4) Li)](2) (R=Me, Et) with R'(2) SnCl(2) (R'=Me, nBu, tBu) afforded a mixture of oligomers (6(Me) SnMe(2), 6(Et) SnMe(2), 6(Me) SnnBu(2), 6(Et) SnnBu(2), 6(Me) SntBu(2), and 6(Et) SntBu(2)). These oligomers were characterized by (1) H, (13) C, (29) Si, and (119) Sn NMR spectroscopy and by mass spectrometry.