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A new protocol in which 2-isocyanophenyl 4-methylbenzoate is used as a convertible isocyanide for Ugi/deprotection + activation/cyclization synthesis of 2,5-diketopiperazine derivatives has been developed. This operational simple procedure displays good functional group tolerance and avoids treatment of typically known offensive isocyanides.

Fluorous and highly fluorinated molecules have special physical, chemical, and biological properties. The development of fluorous technologies has generated a significant impact on the chemistry of macrocyclic and spherical compounds. This paper highlights the synthesis of such compounds and their applications in the fields including catalysis, molecular recognition, surface chemistry, molecular probing, molecular imaging, photomaterials, and nanomaterials.

A thermodynamic analysis of the R404A refrigeration system with an internal heat exchanger using R744 as a secondary refrigerant is presented in this paper to optimize the design for operating parameters of the system. The main results are summarized as follows: The COP increases with increasing subcooling and superheating degree of R404A, internal heat exchanger and compression efficiency of the R404A cycle and evaporating temperature of the R744 cycle and decreasing temperature difference of the cascade heat exchanger and condensing temperature of the R404A cycle. The mass flow ratio decreases with increasing evaporating temperature of the R744 cycle and internal heat exchanger efficiency of the R404A cycle and decreasing subcooling and superheating degree of the R744 cycle, temperature difference of the cascade heat exchanger and condensing temperature of the R404A cycle.

This paper presents the comparison of heat transfer and pressure drop of various secondary refrigerants (single-phase and two-phase) in the indirect refrigeration system. The main results were summarized as follows: In case of heat transfer, it is useful to use secondary refrigerants in low evaporating temperature region and the heat transfer coefficient of single-phase is larger than two-phase secondary refrigerants. In case of pressure drop, it is useful to use secondary refrigerants in high evaporating temperature region and the pressure drop of two-phase is smaller than single-phase secondary refrigerant. Also, is the best useful because pressure drop of among the secondary refrigerants is the smallest.

The three-component Mannich-type reactions of different ketones with various aromatic aldehydes and aromatic amines proceeds efficiently in the presence of catalytic amount of perfluoroalkylated-pyridine in a fluorous biphasic system without fluorous solvent, which has prompted various concerns involving cost, solvent leaching, and environmental persistence. The reactions give various β-arylamino ketones in good to excellent yield. The catalyst can be recovered by simple cooling and precipitation and used again.

采用固相法制备了[(Na x K(1– x )) 0.985 Bi 0.015 ](Nb 0.97 Ti 0.03 )O 3 ( x =0.40~0.65)无铅压电陶瓷, 研究了样品的物相结构、显微形貌、压电以及介电性能随x的变化规律。结果表明: 所有样品都具有钙钛矿结构并且居里温度 T C 在 340~365℃范围内; 当 x =0.40和 x =0.65时, 样品为四方相结构; 在0.45≤ x ≤0.63范围内, 形成了典型的PPT(polymorphic phase transition), 样品表现出较高的压电活性。当 x =0.60时, 样品的压电性能最佳( d 33 =253 pC/N, k p =0.43, T C =359℃)。

A high-yielding, ligand-free, palladium-catalyzed isocyanide insertion reaction for the synthesis of phthalazino[1,2- b ]quinazolinones from the readily obtainable quinazolinones has been developed. Easily handled and relatively low-cost palladium(II) acetate was used as the catalyst, without an additional ligand. Preparation of the quinazolinones involved the cascade reaction of isatoic anhydrides, phenylhydrazines and 2-bromobenzaldehyde catalyzed by p -toluenesulfonic acid in one pot. This novel protocol may be applicable for the synthesis of other important ring-fused heterocyclic compounds.

Combining the Ugi reaction with ring opening reaction of furans for the synthesis of novel isoquinolinone and 1,2-dihydroisoquinoline scaffolds has been developed. The isoquinolinone and 1,2-dihydroisoquinoline derivatives with unsaturated carbonyl moiety may open up many opportunities for further functionalizations.

A simple and convenient tandem reaction of α-ketoesters with primary or secondary aromatic amines for the synthesis of polysubstituted 1,2-dihydroquinolines has been developed. The catalytic system (fluorous hydrazine-1,2-bis(carbothioate)/NCS) of the reaction has the advantages of operational simplicity, high efficiency, as well as easy recyclability.

Transition-metal-free radical access to 1,4-benzothiazine derivatives from o-aminobenzenethiols is disclosed. This procedure is available for various ketones including α,β-unsaturated, cyclic, linear, and fluoroalkyl ketones to generate a number of 1,4-benzothiazines, which exist in numerous bioactive and natural molecules, rendering this protocol attractive to both synthetic and medicinal chemistry.

A newly developed aqueous system with acid and phosphide was introduced in which odorless and stable sodium arylsulfinates can in situ generate arylsulfenyl radicals. These radicals have high reactivity to react with alkynes, alkenes, and H-phosphine oxides for the synthesis of alkyl and alkenyl sulfides and phosphonothioates. The control experiments and quantum calculations are also performed to gain insights into the generation mechanism of arylsulfenyl radicals. Notably, the chemistry is free of thiol odors, organic solvents, and metals.

A 2-fluoro-1,3-dicarbonyl-initiated one-pot Michael addition/[5 + 1] annulation/dehydrofluorinative aromatization reaction sequence is introduced for regioselective synthesis of di-, tri-, tetra-, and pentasubstituted pyridines as well as fused pyridines. This simple and modular synthesis is performed using readily available starting materials and under transition-metal catalyst-free conditions.

The first asymmetric synthesis of spiro-γ-lactam oxindoles bearing three stereocenters is reported. One-pot thiol-Michael/Mannich/lactamization reactions promoted by a recyclable fluorous bifunctional cinchona alkaloid/thiourea organocatalyst afford products in moderate to good yields with up to 95% ee and 6:1 dr.

The first asymmetric synthesis of spiro-γ-lactam oxindoles bearing three stereocenters is reported. One-pot thiol-Michael/Mannich/lactamization reactions promoted by a recyclable fluorous bifunctional cinchona alkaloid/thiourea organocatalyst afford products in moderate to good yields with up to 95% ee and 6:1 dr.

α,α-Difluorodiaroylmethane can be used as a nucleophilic difluoromethylation reagent for generating α-thioaryl-α,α-difluoroacetophenones (Ar1COCF2SAr) and difluoromethylthiolated arenes (ArSCF2H) under transition-metal-free conditions. The reaction selectivity is mainly dependent on temperature. The method has also been extended to the synthesis of α-thioaryl-α-monofluoroacetophenones using α-monofluorodibenzoylmethane. Moreover, the benzoyl cation derived from α,α-difluorodibenzoylmethane can react with nucleophiles to afford the desired products in a one-pot process.

A recyclable fluorous bifunctional Cinchona alkaloid/thiourea-catalyzed and four-component Michael/Mannich/cyclization sequence has been developed for the asymmetric synthesis of spirooxindoles containing 2-piperidinone and tetrahydropyridine rings. This one-pot reaction process affords the products in good to excellent yields and up to 99% ee and 9:1 dr.

A new route for the synthesis of novel spirooxindoles from isocyanides, dialkyl acetylenedicarboxylates, and N-substituted isatylidene derivatives through [3+2] cycloaddition has been developed. This method has several advantages, such as high regioselectivity, high yields, readily available starting materials, and one-pot operations. The synthetic alkyne-containing spirooxindoles could also be used in the selective synthesis of triazole-containing­ spirocyclic compounds using a copper azide–alkyne cycloaddition­ (CuAAC) reaction.

An efficient chemoselective methodology for the syntheses of unsymmetrical bis(1,2,3-triazole) derivatives has been developed. This protocol utilizes alkynyl-substituted amines as bifunctional linkers to conjoin a copper-free three-component cycloaddition with a copper(I)-catalyzed alkyne–azide cycloaddition in a one-pot procedure. In addition, we used this method for the construction of unsymmetrical bis(1,2,3-triazole)-modified peptidomimetics through a combination of multicomponent reactions taking place in a sequential process, which may be utilized in biological applications.

An efficient copper-free protocol for the synthesis of 5-methyl-1H-1,2,3-triazole-modified peptidomimetics through the combination of Ugi four-component reaction with a three-component cycloaddition, has been developed. The copper-free straightforward process is suitable for drug discovery. The chemoselective preparation of 1,4-disubstituted, triazole-modified peptidomimetics by using alkynyl substituted amines may have potential biological and synthetic application. At last, a "Lapinski type" analysis of the physical properties was performed, which is expected to help drug discovery.

The treatment of commercially available polymethyl methacrylate (PMMA) microspheres with palladium (Pd)Cl2 and formaldehyde, generated supported Pd(0)-PMMA with 0.79 (wt)% catalyst loading. The catalyst has been used for copper- and ligand-free Sonogashira reactions in aqueous media. It is highly reactive for the reactions of iodobenzenes with aryl acetylenes or alkyl acetylenes. The performance of the recovered catalyst had no significant difference in five cycles. The Pd leaching was detected at a very low level (2.1–9.8 ppm) for each cycle. PMMA-supported PdCl2, Pd(OAc)2, PdCO3, and PdCl2(MeCN)2 have also been tested for Sonogashira reactions.

The nonmetal catalytic oxidation system I2/tert-butyl hydroperoxide (TBHP) has been unprecedentedly applied to a three-component domino reaction and simultaneously a simple and efficient protocol has been developed to newly synthesize 2-aryl-N-substitutied quinazoline-4-amines in one pot from isatoic anhydride, aromatic amine, and another amine containing methylene adjacent to nitrogen. This protocol is new and practical because both the electron-donating and -withdrawing groups substituted on amines 2 or 3 can survive and provide the corresponding products in reasonable yields. Iodine is essential to the three-component, one-pot reaction unlike the step-wise procedure.

A new fluoroalkylated 1,4-disubstituted [1,2,3]-triazole was prepared and acted as an efficient ligand in the palladium-catalyzed Suzuki–Miyaura coupling reactions of aryl boronic acids and aryl halides (Ar–Br and Ar–Cl) and Mizoroki–Heck reactions of aryl halides and alkenes. All reactions proceeded smoothly to give the desired products in moderate to excellent yields under the optimal conditions. Moreover, the ligand could be easily recovered by fluorous solid-phase extraction with excellent purity and reused with slightly decrease in its activity.

A convenient method for Morita–Baylis–Hillman reaction of arylaldehydes with methyl acrylate has been developed by using fluorous-tag organocatalyst 1-[4-(perfluorooctyl)phenyl]-3-phenylthiourea and DABCO at room temperature. The fluorous organocatalyst could be recovered from the reaction mixture by fluorous solid-phase extraction (F-SPE) with excellent purity for direct reuse.

As a kind of organocatalyst, 1-[4-(perfluorooctyl)phenyl]-3-phenylthiourea was employed to the chemoselective oxidation of sulfides in the presence of 30% H 2 O 2 . A variety of diaryl, dialkyl, alkyl aryl sulfides could be oxidized to sulfoxide under the mild condition. The catalyst could be easily recovered by fluorous solid-phase extraction for reuse.

Hafnium (IV) bis(perfluorooctanesulfonyl)imide complex is found to be an efficient catalyst for the multicomponent condensation of β-naphthol, aromatic aldehydes and urea or amides in perfluorodecalin to afford the corresponding substituted amidomethyl naphthols in good yields. The remarkable features of this new procedure are high yields, shorter reaction times, reusability of catalyst and simple work-up procedures.

A new fluoroalkylated 1,4-disubstituted [1,2,3]-triazole was prepared and acted as an organocatalyst for aldol condensation of different ketones with various aldehydes. Aldol condensation proceeded efficiently in the presence of catalytic amount of fluoroalkylated [1,2,3]-triazole. The catalyst could be easily recovered by fluorous solid-phase extraction with excellent purity and reused for three runs with slightly decrease in its activity.

A commercially available perfluorooctyl aniline and phenyl isothiocyanate were reacted under mild conditions to give 1-[4-(perfluorooctyl)phenyl]-3-phenylthiourea as an analogue of thiourea-based organocatalyst. This fluorous organocatalyst was successfully employed to direct reductive amination of aldehydes. It could be readily separated from reaction product by fluorous solid phase extraction for direct use.

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(NPf 2 ) 4 in C 10 F 18 at 60 °C. The method offers several advantages including high yields, short reaction time, simple work-up procedure and catalyst reusability.

The synthesis of 1,5-benzodiazepine derivatives was smoothly carried out in a fluorous aqueous emulsion system composed of perfluorooctane (C 8 F 18 ) and potassium perfluorooctanesulfonate (C 8 F 17 SO 3 K, KFOS) at room temperature. The aqueous perfluorinated emulsion can be recovered and used again without a significant loss of efficiency.

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.

Aldol condensation of different ketones with various aromatic aldehydes proceeds efficiently in the presence of catalytic amount of perfluoroalkylated-pyridine in a fluorous biphasic system without fluorous solvent, which has prompted various concerns involving cost, solvent leaching, and environmental persistence. The catalyst can be recovered by simple cooling and precipitation and used again.

Perfluorooctanesulfonic acid (CF3(CF2)7SO3H, PFOS) efficiently catalyzes the nitrolysis of hexamethylenetetramine in fluorous media, affording a good yield of the explosive HMX. The reaction can be carried out without acetic anhydride or acetic acid. The fluorous phase containing the catalyst could be easily separated and can be reused several times without significant loss of catalytic activity.

The new phase-separation and immobilization technique known as fluorous biphase system (FBS) has become an active topic among researchers in both industry and academia. A series of fluorous biphasic reactions catalyzed by Lewis acid-type metal perfluorooctanesulfonates and metal bis(perfluorooctanesulfonyl)amides are reviewed in this paper. The recent development of fluorous phase transfer catalyst (PTC) is also discussed.

Amberlyst A-21, a kind of well-known and cheap polymeric material, was treated with palladium perfluorooctanesulfonate [Pd(OPf) 2 ] giving a reagent with a palladium loading of 1.94 (wt%). The polymer-supported fluorous palladium catalyzes the highly efficient Sonogashira coupling reaction in water. The reactions can be performed under copper- and ligand-free conditions in an air atmosphere. The palladium catalyst is easily separated and can be reused several times without a significant loss of catalytic activity.

Synthesis of trisubstituted imidazoles was successfully accomplished using rare earth(III) perfluorooctanesulfonates (RE(OPf) 3 ), RE = Sc, Y, La–Lu as catalysts in fluorous solvents. Ytterbium perfluorooctanesulfonates (Yb(OPf) 3 ) catalyze the high efficient synthesis of trisubstituted imidazoles in fluorous solvents. By simple separation, fluorous phase containing only catalyst can be reused several times.

Amberlyst A-21, a kind of well-known and cheap polymeric material, was treated with ytterbium perfluorooctanesulfonate [Yb(OPf)3] giving a reagent with a ytterbium loading of 1.34 (wt%). The polymer-supported fluorous ytterbium catalyses the highly efficient nitration, esterification, Fridel-Crafts acylation, and aldol condensation. The catalyst can be recovered by simple filtration and used again without a significant loss of catalytic activity. The protocol avoids the use of fluorous solvents during the reaction or workup, which are expensive and can leach in small amounts.

Breaking and inhibiting foam performance of silicone oil modified with alkyl and perfluoroalkyl groups in oil‐based system has been studied. Factors related with foam controlling performance, such as surface tension and solubility property, were analyzed.

Knoevenagel condensation proceeds efficiently in the presence of catalytic amount of perfluoroalkylated pyridine under homogeneous conditions in n-octane at 80 °C. The catalyst can be recovered by simple cooling and precipitation and used again. The protocol avoids the use of fluorous solvents during the reaction or workup, which is expensive and can leach in small amounts.

Perfluorooctanesulfonic acid (CF(3)(CF(2))(7)SO(3)H, PfOS) catalyses the highly efficient nitrolysis of hexamethylenetetramine in fluorous media, affording high yield of explosive RDX. The reaction can be carried out at room temperature in the absence of acetic anhydride and produces smaller amounts of waste acid and nitrate than in traditional process. The fluorous phase containing catalyst could be easily and efficiently recovered for reuse by simple phase separation.

Polymethyl methacrylate (PMMA) micro-spheres, a kind of commercially available polymeric material was treated with PdCl2 and formaldehyde giving a reagent with a palladium loading of 0.79 (wt.%). The Pd-PMMA catalyzed the highly efficient Heck and Suzuki reactions. The reactions can be performed under ligand-free conditions in an air atmosphere. The palladium catalyst is easily separated and can be reusable with negligible leaching of palladium.

A series of polysiloxanes modified with fluoroalkyls and polyethers were synthesized. Antifoaming performance of such modified polysiloxanes in the mixture of diesel and mobile fuel was studied. The effects of factors such as polyethers type, molar ratio between polyether and fluoroalkyl, hydrogen-contents and viscosity of polysiloxanes, length of fluoroalkyls, etc., on the performance of modified products were discussed. It shows that polysiloxane modified with allyl polyoxypropylene ether and hexafluorobutyl acrylate has better breaking and inhibiting foam performance, when compared with that replacing allyl polyoxypropylene ether with allyl polyoxyethylene polyoxypropylene block ether and allyl polyoxyethylene ether. And when the molar ratio between allyl polyoxypropylene ether and hexafluorobutyl acrylate is 3 : 7, modified polysloxane has the best foam controlling performance. Low viscosity polysiloxane or low hydrogen content polysiloxane modified with allyl polyoxypropylene ether and hexafluorobutyl acrylate has better foam controlling performance. Polysiloxane modified with longer carbon chain fluoroalkyl and allyl polyoxypropylene ether has better antifoaming performance than that modified with shorter carbon chain fluoroalkyl and polyether and lower surface tension. The change of surface tension of foaming liquid between initially added with modified polysiloxane and after testing antifoaming performance was studied, and it shows that after testing performance of antifoam, the surface tension of foaming liquid becomes bigger which is one possible reason for antifoam exhausting. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

α,α-Difluorodiaroylmethane can be used as a nucleophilic difluoromethylation reagent for generating α-thioaryl-α,α-difluoroacetophenones (Ar(1)COCF2SAr) and difluoromethylthiolated arenes (ArSCF2H) under transition-metal-free conditions. The reaction selectivity is mainly dependent on temperature. The method has also been extended to the synthesis of α-thioaryl-α-monofluoroacetophenones using α-monofluorodibenzoylmethane. Moreover, the benzoyl cation derived from α,α-difluorodibenzoylmethane can react with nucleophiles to afford the desired products in a one-pot process.

Ytterbium perfluorooctanesulfonate [Yb(OPf) 3 ] catalyses the highly efficient Henry reaction in the presence of a catalytic amount of a novel perfluoroalkylated-pyridine as a ligand in a fluorous biphase system (FBS) composed of toluene and perfluorodecalin. An unprecedented chemoselective addition of aldehydes among various carbonyl compounds and the robustness of the catalytic system for recycling using by simple phase-separation were obtained.