Metal bis(perfluorooctanesulfonyl)amides as highly efficient Lewis acid catalysts for fluorous biphase organic reactions

In fluorous biphase system, metal bis(perfluorooctanesulfonyl)amides are better Lewis acid catalysts than the analogous triflates toward either transesterifications, or direct esterifications, or Friedel-Crafts acylations or Baeyer-Villiger oxidations. These catalysts are selectively soluble in lower fluorous phase and can be recovered simply by phase separation. Furthermore, these catalysts can be reused without decrease of activity in most cases.     

Recyclable and selective Lewis acid catalysts for transesterification and direct esterification in a fluorous biphase system: tin(IV) and hafnium(IV) bis(perfluorooctanesulfonyl)amide complexes

Tin(IV) and hafnium(IV) bis(perfluorooctanesulfonyl)amide complexes were shown to give excellent yield and selectivity for highly practical transesterification and direct esterification, respectively, with an equimolar ratio of the reactants in a fluorous biphase system. It was found that these metal complexes were completely recovered and reused in the immobilized fluorous phase without loss of their catalytic activities.     

Hafnium (IV) bis(perfluorooctanesulfonyl)imide complex catalyzed synthesis of polyhydroquinoline derivatives via unsymmetrical Hantzsch reaction in fluorous medium

A facile and efficient synthesis of polyhydroquinoline derivatives was reported via four-component condensation reaction of aldehydes, dimedone, active methylene compounds, and ammonium acetate in the presence of Hf(NPf₂)₄ in C₁₀F₁₈ at 60 °C. The method offers several advantages including high yields, short reaction time, simple work-up procedure and catalyst reusability.     

Hf[N(SO2C8F17)2]4-catalyzed Friedel-Crafts acylation in a fluorous biphase system

In a fluorous biphase system, Hf[N(SO₂C₈F₁₇)₂]₄ complex (1 mol %) catalyzes Friedel-Crafts acylation of aromatic compounds such as anisole, toluene and chlorobenzene, and the corresponding aromatic ketones are obtained in satisfactory to high yields. The catalyst is selectively soluble in lower fluorous phase and can be easily recovered by simple phase separation. Furthermore, the catalyst can be reused without decrease of activity in most cases.     

Rare earth(III) perfluorooctanesulfonates catalyzed Friedel-Crafts alkylation in fluorous biphase system

The catalyst of rare earth(III) perfluorooctanesulfonates (RE(OSO₂C₈F₁₇)₃, RE = Sc, Y, La-Lu) were prepared from either rare earth chlorides(III) or oxides and perfluorooctanesulfonic acid. The perflates thus obtained act as novel catalysts for Friedel-Crafts alkylation in fluorous biphasic system. Perfluorohexane (C₆F₁₄), perfluoromethylcyclohexane (C₇F₁₄), perfluorotoluene (C₇F₈), perfluorooctane (C₈F₁₈), perfluorooctyl bromide (C₈F₁₇Br) and perfluorodecalin (C₁₀F₁₈, cis- and trans-mixture) can be used as fluorous solvents for this reaction. By simple separation of the fluorous phase containing only catalyst, alkylation can be repeated many times.     

Rare earth(III) perfluorooctane sulfonates and perfluorooctanesulfonic acid in fluorous solvents: Novel and recyclable catalytic systems for Friedel-Crafts acylation of unactivated benzenes

Catalytic Friedel-Crafts acylation of benzene and unactivated benzenes, such as chlorobenzene and fluorobenzene, was successfully accomplished using rare earth(III) perfluorooctane sulfonates (RE(OPf)₃), RE = Sc, Y, La ∼ Lu) and perfluorooctanesulfonic acid (PfOH) as catalysts in fluorous solvents. Solutions of Yb(OPf)₃ and PfOH in perfluorodecalin (C₁₀F₁₈, cis and trans-mixture) are the most suitable catalytic system, with catalyst loading as low as 0.4%mol leading to clean, high-yielding benzoylation of a variety of unactivated benzenes. By simple separation of the fluorous phase containing only catalyst, acylation can be repeated several times.     

A convenient method for the preparation of mono- and bis-substituted photochromic bis(benzothienyl)perfluorocyclopentenes via regioselective Friedel-Crafts acylation

The regioselective Friedel-Crafts acylation of 1,2-bis(2-methylbenzo[b]thien-3-yl)hexafluorocyclopentene was developed. Depending on the reaction conditions, mono- or bis(bromoacetyl) derivatives are formed as single products in good yields. Further heterocyclizations involving α-bromoketone moieties gave a series of new photochromic compounds.     

Lanthanide bis(trifluoromethanesulfonyl)amides, synthesis, characterization and catalytic activity

The synthesis of lanthanum, neodymium and ytterbium bis(trifluoromethanesulfonyl)amides, named triflimidates, from acetates, carbonates and oxides is investigated. When the synthesis is performed in water, all the salts contain one molecule of water and the lanthanum and neodymium salts synthesized from the acetates also contain one molecule of acetic acid. After removal of the water and acetic acid in refluxing ethanol, the salts are obtained anhydrous but associated for lanthanum and neodymium, whereas the ytterbium salt is monomeric and volatile. When the synthesis is performed directly in ethanol, the neodymium salt contains two molecules of coordinated ethanol.In non-hazardous solvents, these triflimidates are better catalysts than the analogous triflates toward either Friedel-Crafts acylations, or Fries transpositions or Baeyer-Villiger oxidations. Unexpectedly, the cerium(IV) triflimidate catalyzes the oxidation of aromatic ketones to give the corresponding acids.     

Yb[N(SO2C8F17)2]3-catalyzed allylation of 1,3-dicarbonyl compounds with allylic alcohols in a fluorous biphase system

Allylation of 1,3-dicarbonyl compounds with allylic alcohols was successfully accomplished using rare earth metal (III) bis(perfluorooctanesulfonyl)imide [RE(NPf₂)₃, RE = La∼Lu] as catalysts in fluorous solvents. Ytterbium bis(perfluorooctanesulfonyl)imide [Yb(NPf₂)₃] catalyzes the high efficient reaction of allylation in fluorous solvents. By simple separation, fluorous phase containing only catalyst can be reused several times.     

‘Fluorous nanoflow’ system for the Mukaiyama aldol reaction catalyzed by the lowest concentration of the lanthanide complex with bis(perfluorooctanesulfonyl)amide ponytail

‘Fluorous nanoflow’ system is extremely effective for the lanthanide bis(perfluorooctanesulfonyl)amide-catalyzed Mukaiyama aldol reaction with dramatic increase in the reaction rate by the continuously controlled nano feeder. Thus, the acceleration of the aldol reaction was achieved even in the lowest concentration (<0.0001 M) of the lanthanide fluorous catalyst and, hence, the reaction completed within seconds as a bi-phase contact time in the micro cell.     

Synthesis and characterization of sodium bis(trimethylstannyl) amide and bis(trimethylsilyl) bis(trimethylstannyl) -phospha-tetrazene

Sodium bis(trimethylstannyl)amide NaN(SnMe₃)₂, isolated by the reaction of trimethylstannyldiethylamine with sodium amide, reacts with tris(trimethylsilyl)hydrazino—dichloro-phosphine to form bis(trimethylsilyl)bis(trimethylstannyl)-2-phospha-2-tetrazene, (Me₃Si)₂N-N=P-N(SnMe₃)₂. Both the molecules have been isolated and characterized.     

Mannich-type reactions of aromatic aldehydes, anilines, and methyl ketones in fluorous biphase systems created by rare earth (III) perfluorooctane sulfonates catalysts in fluorous media

Rare earth (III) perfluorooctane sulfonates (RE(OPf)₃) catalyze the three-component Mannich-type reactions of different ketones with various aromatic aldehydes and aromatic amines in fluorous media to give various β-arylamino ketones in good yields. By simple separation of the fluorous phase containing only catalyst, reaction can be repeated several times.     

Heptadecafluorooctanesulfonic acid (C8F17SO3H) catalyzed intramolecular hydroamination of olefinic sulfonamides in fluorous biphase system (FBS)

A practical, efficient, and environmentally benign intramolecular hydroamination of olefinic sulfonamides was carried out in fluorous biphase system (FBS) using commercially available heptadecafluorooctanesulfonic acid (C₈F₁₇SO₃H) as a catalyst and perfluorodecaline (C₁₀F₁₈, cis- and trans- mixture) as a fluorous solvent to produce the corresponding cyclic products in good yields. The Brønsted acid of C₈F₁₇SO₃H is easily recovered and recycled at least five times.     

Synthesis and Structural Characterization of Bis(tetrahydro­pyran)calcium Bis[bis(trimethylsilyl)amide]

Transmetalation of Sn[N(SiMe₃)₂]₂ with calcium granules in tetrahydropyran (thp) yields colorless [(thp)₂Ca{N(SiMe₃)₂}₂] ( 1 ) which is soluble in common organic solvents. The calcium center is in a distorted tetrahedral environment with Ca–N and Ca–O bond lengths of 231.08(11) and 240.23(9) pm, respectively. The molecular structure is dominated by steric factors leading to a NCaN bond angle of 119.43(6)°.     

Catalytic application of dinuclear palladium(II) bis(thiosemicarbazone) complex in the Mizoroki-Heck reaction

A convenient synthesis of new square planar dinuclear palladium(II) terephthaldehyde bis(thiosemicarbazone) complex has been described. The compositions of the complex have been established by elemental analysis, spectral methods and single crystal X-ray crystallographic technique. The new complex acts as an active recyclable homogeneous catalyst for the Mizoroki-Heck reaction of electron deficient (activating) and electron rich (deactivating) aryl halides with various olefins under optimized conditions.     

Malonate-type bis(oxazoline) ligands with sp hybridized bridge carbon: synthesis and application in Friedel-Crafts alkylation and allylic alkylation

A series of simple and new C₂-symmetric diphenylmethylidene malonate-type bis(oxazoline) ligands were synthesized and applied to the Friedel-Crafts reaction and allylic alkylation. The Cu(II) complex of ligand 4b bearing the benzyl group afforded good to excellent enantioselectivity for the F-C adducts (up to >99% ee) between indole and alkylidene malonate, and the palladium complex of ligand 4c bearing the phenyl group afforded excellent enantioselectivity (up to 94% ee) for the allylic alkylation product.     

Synthesis of (2-chlorophenyl)(phenyl)methanones and 2-(2-chlorophenyl)-1-phenylethanones by Friedel-Crafts acylation of 2-chlorobenzoic acids and 2-(2-chlorophenyl)acetic acids using microwave heating

Several 2-(2-chlorophenyl)-1-phenylethanones and (2-chlorophenyl)(phenyl)methanones were prepared by the Friedel-Crafts acylation reaction of 2-(2-chlorophenyl) acetic acids and 2-chlorocarboxylic acids, respectively, in the presence of cyanuric chloride, pyridine, and AlCl₃ or FeCl₃ using microwave heating. The yields of the ketones were significantly higher than those obtained using conventional heating. In addition, similar reactions carried out with the less inexpensive and less toxic FeCl₃ gave titled ketones in comparable yields. Interestingly, the FeCl₃ catalyzed reactions gave pure ketones (no chromatographic purification required), whereas the AlCl₃ catalyzed reaction gave impure product that required chromatographic purification.     

One-pot solvent-free synthesis of triaryl- and triheteroarylmethanes by Bi(OTf)3-catalyzed Friedel-Crafts reaction of arenes/heteroarenes with trialkyl orthoformates

A convenient, practical and highly efficient one-pot method has been developed for the synthesis of triaryl- and triheteroarylmethane derivatives by Bi(OTf)₃-catalyzed Friedel-Crafts alkylation of trialkyl orthoformates in combination with a wide variety of arenes/heteroarenes at room temperature under solvent-free conditions and in an air atmosphere. The methodology offers an operational simplicity, high atom economy and environmentally benign procedure. Furthermore, selected compound 3k showed promising anti-inflammatory activity with inhibition nitric oxide and did not exhibit significant cytotoxic effects on macrophage cells.     

含1-(2-甲氧乙基)茚基和二(三甲硅基)胺基的稀土有机配合物的合成和表征

无水三氯化稀土（ＬｎＣｌ３），二（三甲硅基）胺基钾（ＬｉＮ（ＳｉＭｅ３）２〗及１－（２－甲乙基）茚室温上在四氢呋喃溶剂中反应，得到了４个含１－（２－甲氧乙基）茚基和二（三甲硅基）胺基的稀土金属有机物｛（Ｃ９Ｈ６ＣＨ２Ｃ２ＯＭｅ）Ｌｎ〖Ｎ（ＳｉＭｅ３）２〗２（Ｌｎ＝Ｎｄ，Ｓｍ，Ｄｙ，Ｙｂ）｝，这些配合物均经元素分析、ＩＲ和ＭＳ表征。     

Synthesis of palladium complexes with bis(diphenylphosphinomethyl)amino ligands: A catalyst for the Heck reaction of aryl halide with methyl acrylate

A series of ligands, (Ph₂PCH₂)₂NR (R = -CH₃) (1), -C(CH₃)₃, (2) -m-C₆H₄SO₃Na (3), and their Pd(II) complexes have been synthesized under nitrogen atmosphere using Schlenk method. All compounds were characterized using elemental analysis and spectroscopic techniques (AAS, NMR (¹H, ³¹P)). Based on the analysis the complexes have been proposed as in square planar geometry. The Pd(II) complexes were applied to the Heck reaction of aryl halide (Br, Cl) with methyl acrylate. The results have exhibited that complexes [PdCl₂((Ph₂PCH₂)₂NCH₃)] (4) and [PdCl₂((Ph₂PCH₂)₂NC(CH₃)₃)] (5) have shown higher turnover numbers (TON) than complex [PdCl₂(Ph₂PCH₂)₂N-m-C₆H₄SO₃Na] (6).