Ring-opening Copolymerization of Adipic Anhydride and Propylene Oxide Catalyzed by Yttrium Triflates

The ring-opening copolymerization of adipic anhydride with propylene oxide was carried out with yttrium triflates as a catalyst. Poly（propylene adipate） could be synthesized by controlling the copolymerization conditions. The copolymerization procedure was tracked by ^1H NMR analyses.

Rare earth metal triflates catalyzed electrophilic nitration using N_2O_5

A mild,efficient and eco-friendly process for the electrophilic nitration is described using N_2O_5 as a green nitrating agent in the presence of rare earth metal triflates[RE（OTf）_3]under mild conditions.

Palladium-Catalyzed Desulfinative Cross-Coupling of Polyhalogenated Aryl Triflates with Aryl Sulfinate Salts:Inversion of Traditional Chemoselectivity

Comprehensive Summary This paper presents the first general examples of palladium-catalyzed desulfinative cross-coupling reaction of polyhalogenated aryl triflates with aryl sulfinate salts showing an inversion of the conventional reactivity order of C-Br>C-Cl>C-OTf.The catalyst system,comprising of Pd(OAc)_(2)and tBuPhSelectPhos,exhibited excellent catalytic reactivity and chemoselectivity toward this reaction.This reaction had a wide range of substrate scopes and provided a simple and efficient method for the construction of functionalized biaryl motifs.Notably,the C-H···Pd interaction from the methine hydrogen of the C2-cyclohexyl group of the indolyl phosphine ligand with the Pd center may contribute a key factor in reactivity and chemoselectivity.Assisting with density functional theory(DFT)calculations,the results revealed that the oxidative addition step in this reaction was a controlling-chemoselectivity step.

Nickel-catalyzed reductive coupling reaction of monofluoroalkyl triflates with alkyl carboxylic acids toward the synthesis of α-alkyl-α-fluoro-alkylketones

The synthesis methods ofα-fluoro-arylketones were well-established through electrophilic/nucleophilic fluorination and transition metal catalyzed cross-coupling.However,due to the site selectivity and substrate restriction,only a few cases have been developed to affordα-alkyl-α-fluoro-alkylketones.Herein,we report a general and efficient method of preparing diverseα-alkyl-α-fluoro-alkylketones via nickelcatalyzed reductive coupling reaction of monofluoroalkyl triflates with low-cost industrial raw material alkyl carboxylic acids.These transformations demonstrate high efficiency,mild conditions,and excellent functional group compatibility.This strategy provides a general and efficient method for the synthesis ofα-alkyl-α-fluoro-alkylketones。

Pd-catalyzed cross-coupling of polyfluoroarenes with cyclic vinyl triflates

An effective method for Pd-catalyzed cross-coupling between polyfluoroarenes and cyclic vinyl triflates has been developed.This protocol provides a useful and facile access to polyfluoroarylated cyclic alkenes that are difficult to prepare otherwise.The advantages of this method are its high efficiency and operational simplicity.

4-(Benzylamino)formoyldiphenylammonium Triflate (BDPAT):An Efficient, Recoverable Biphasic Catalyst For Esterification of Carboxylic Acids with Equimolar Amounts of Alcohols

Esterification of carboxylic acid with equimolar amounts alcohol can be efficiently catalyzed by biphasic 4-(benzylamino)formoyldiphenylammonium triflate (BDPAT, 3) in good yield. The catalyst can be easily recovered without loss of activity.

A facile synthesis of 2,3-dihydro-2-aryl-4(1H)-quinazolinones catalyzed by scandium(Ⅲ) triflate

2,3-Dihydro-2-aryl-4（1H）-quinazolinones were prepared in good yields via condensation of o-aminobenzamide with aldehydes promoted by a catalytic amount of Sc（OTf）3 under mild conditions.

Zirconium triflate grafted on SBA-15 as a highly efficient solid acid catalyst for ring opening of epoxides by amines and alcohols

Metal(Al,Ti,Zr)triflate grafted mesoporous SBA‐15(AlTf/S,TiTf/S,ZrTf/S)samples were synthesizedas inexpensive solid acid materials by a simple one‐pot‐two‐step synthesis methodology.These materials were characterized by X‐ray diffraction,N2‐sorption,thermogravimetric analysis,Fourier transform infrared spectroscopy(FT‐IR),in‐situ pyridine FT‐IR spectroscopy,and elementalanalysis.ZrTf/S was found to be a highly efficient and reusable solid acid catalyst for ring opening ofepoxides with amines and alcohols and producedβ‐amino alcohols andβ‐alkoxy alcohols respectivelyunder ambient reaction conditions.The ZrTf/S catalyst showed the highest activity,whichwas attributed to its high acidity compared with that of the Ti and Al containing samples.

Oxone-Mediated Oxidative Esterification of Heterocyclic Aldehydes Using Indium(III) Triflate

Recent investigations have shown the oxone-mediated oxidative methyl esterification of benzaldehyde derivatives using methanol. The reactions were accelerated in the presence of indium(III) triflate, a trivalent indium reagent, in many cases. Based on this method of methyl esterification of benzaldehyde derivatives, we further explored an application to heterocyclic aldehydes. The reactions were examined using methanol as well as other alcohols in order to establish a suitable range.

Silica triflate as an efficient reagent for the solvent-free synthesis of coumarins

Silica triflate, as a new silica-based reagent, can be used for the efficient synthesis of 4-substituted coumarins via a Pechmann reaction under solvent-free reaction conditions. All reactions were performed at 80 ℃ in good to high yields.

Aluminum(Ⅲ) triflate-catalyzed selective oxidation of glycerol to formic acid with hydrogen peroxide

Glycerol is a by-product of biodiesel production and is an important readily available platform chemical.Valorization of glycerol into value-added chemicals has gained immense attention.Herein,we carried out the conversion of glycerol to formic acid and glycolic acid using H2O2 as an oxidant and metal(Ⅲ)triflate-based catalytic systems.Aluminum(Ⅲ)triflate was found to be the most efficient catalyst for the selective oxidation of glycerol to formic acid.A correlation between the catalytic activity of the metal cations and their hydrolysis constants(Kh)and water exchange rate constants was observed.At 70 ℃,a formic acid yield of up to 72% could be attained within 12 h.The catalyst could be recycled at least five times with a high conversion rate,and hence can also be used for the selective oxidation of other biomass platform molecules.Reaction kinetics and 1H NMR studies showed that the oxidation of glycerol(to formic acid)involved glycerol hydrolysis pathways with glyceric acid and glycolic acid as the main intermediate products.Both the [Al(OH)x]^n+ Lewis acid species and CF3SO3H Brosted acid,which were generated by the in-situ hydrolysis of Al(OTf)3,were responsible for glycerol conversion.The easy availability,high efficiency,and good recyclability of Al(OTf)3 render it suitable for the selective oxidation of glycerol to high value-added products.

A Novel Initiator Containing Alkyne Group for the Polymerization of 2-Ethyl-2-oxazoline

A novel trifunctional initiator with one alkyne and two trifluoromethanesulfonate moieties was synthesized from a protected alcohol 5-hydroxyl-2-phenyl-1, 3-dioxane. The alkyne func- tionalized intermediate with two protected alcohol groups was synthesized by reacting with propargyl bromide. The alcohol groups were cleaved using a mixture of tetrahydrofuran and hydrochloric acid aqueous solution. In the last step the initiator was synthesized us- ing triflic anhydride in carbon tetrachloride. The initiator was characterized by 1H NMR and used for the polymerization of 2-ethyl-2-oxazoline which gives polymers with narrow distribution. For comparison a similar initiator with two tosylates was prepared and used for the polymerization of the monomer 2-ethyl-2-oxazoline, the resulting product has a wide molecular weight distribution and most of the initiator remains unreacted after 24 h which may be due to the steric hindrance between the two tosylate groups. To further explore the steric hindrance phenomenon, a linear tosylate initiator was synthesized, but still some of the initiator remains unreacted, illustrating that both steric hindrance and electrophilic balance affect the efficiency of the cationic ring-opening polymerization. All of the polymers were characterized in detail by using IH NMR, matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy, and size exclusion chromatography to confirm the purity and distribution of the polymers.

Highly-Efficient Conversion of Primary Amides to Nitriles Using Indium(III) Triflate as the Catalyst

Indium(III) triflate, a trivalent indium reagent, was shown to be a highly-efficient catalyst for the conversion of primary amides to the corresponding nitriles. The successful reactions required 5 mol% of indium(III) triflate, and toluene was proved to be the most suitable solvent. Various amides were subjected to this method, and each produced the corresponding nitriles in excellent yields.

Effect of Added Cu(OTf)₂on the Cu(OTf)₂(Py)₄-Mediated Radiofluorination of Benzoyl and Phthaloylglycinates

Cu(OTf)2(Py)4 mediated radiofluorination of the boronate esters of ethyl benzoyl and phthaloylglycinates (11 and 16) using 10 mol% of the copper complex following the literature procedure did not provide the fluorinated products. However, the addition of Cu(OTf)2resulted in the radio-fluorination of the boronate esters 11 and 16 to obtain ethyl 4-[18F]fluorobenzoyl glycinate, 17, (48%) and ethyl 3-[18F]phthaloylglycinate (41%) respectively.

Oxone-Mediated Preparation of Ester Derivatives Using Indium(III) Triflate and Various Alcohols

Esters are known as one of the most fundamental chemical moieties and also essentially useful components, especially for medicinal agents. Herein, using benzaldehyde and its derivatives as starting materials, Oxone-mediated preparation of ester derivatives in the presence of a catalytic amount of indium(III) triflate is described. Alcohols with various chain lengths, which functioned as solvents and substrates, were examined. Overall, the oxidative esterification starting with benzaldehyde derivatives possessing electron withdrawing groups proceeded smoothly and gave sufficient yields, in comparison to the reactions with the derivatives having electron donating groups.

Nitroxide-Mediated Photo-Controlled/Living Radical Polymerization of Methacrylic Acid

The photo-controlled/living radical polymerization of methacrylic acid (MAA) was performed at room temperature by irradiation with a high-pressure mercury lamp using azo initiators and 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl as the mediator in the presence of (4-tert-butylphenyl)diphenylsulfonium triflate (tBuS) as the accelerator. Whereas the bulk polymerization yielded polymers with a bimodal molecular weight distribution in both the absence and presence of tBuS, the solution polymerization in methanol produced unimodal polymers with the molecular weight distribution of 2.0 - 2.3 in the presence of tBuS. The molecular weight distribution of the resulting poly (MAA) decreased with an in- crease in tBuS. The dilution of the monomer concentration also reduced the molecular weight distribution. The use of the initiator with a low 10-h half-life temperature also effectively controlled the molecular weight. The livingness of the polymerization was confirmed by obtaining linear increases in the first-order conversion versus time, the molecular weight versus the conversion, and the molecular weight versus the reciprocal of the initiator concentration.

新型五氟苯铵三氟有机催化剂高效合成14-芳基(烷基)-14H-二苯并[a,j]呫吨类化合物和1,8-二氧代氧杂蒽衍生物(英文)

A simple and facile synthesis of 14-aryl and alkyl-14H-dibenzo[a,j]xanthenes and 1,8-dioxooctahydroxanthene derivatives has been successfully developed by treatment of β-naphthol or dimedone with aldehydes under mild conditions in the presence of a pentafluorophenyl ammonium triflate(PFPAT) organocatalyst.These catalytic condensation reactions represent green chemical processes and the PFPAT organocatalyst is air-stable,cost-effective,easy to handle,and easily removed from the reaction mixtures.

Yb(OTf)_3-catalyzed synthesis of pyrroles under solvent-free conditions

A Yb（OTf）3-catalyzed approach for the synthesis of pyrroles under solvent-free conditions was achieved, which could afford the desired products with yields ranged from moderate to excellent.

Yb(OTf)_3 Catalyzed Nucleophilic Conjugate Addition of Pyrrole to α,β-Unsaturated Ketones and Nitro-compounds

Under the catalysis of Yb(OTf)3, nucleophilic conjugate addition of pyrrole to electron deficient olefins in CH2Cl2 at ambient temperature gives corresponding 2-alkylated pyrrole derivatives in good yields with high selectivity.

Oil recovery tests with ionic liquids: A review and evaluation of 1-decyl-3-methylimidazolium triflate

The main advantages of the use of ionic liquids in enhanced oil recovery are their tunability and stability in harsh environmental conditions. In this work, a comprehensive review of ionic liquids proposed to improve current chemical oil recovery methods has been presented, focusing on core flooding experiments. With an almost infinite number of possible ionic liquids, the amount of experiments carried out up to now has been very limited. However, results are promising, with additional recovery after secondary flooding of up to 32% of the original oil in place. Most formulations with ionic liquids have been proposed for sandstone reservoirs, the number of studies with carbonate cores being very scarce. The possibilities of a new room temperature surface active ionic liquid, 1-decyl-3-methylimidazolium triflate,for this application were analyzed. It was shown that it is able to drastically reduce the water/oil interfacial tension. An optimized formulation was proposed for carbonate reservoirs. After secondary flooding with brine, an additional recovery of 10.5% of original oil in place was achieved at room conditions. A combination of the proposed method followed by a polymer flooding step with polyacrylamide led to a lesser but still significant recovery, reducing the costs associated to the ionic liquid.