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A novel method for the synthesis of 3-monohalooxindoles by acidolysis of isatin-derived 3-phosphate-substituted oxindoles with haloid acids was developed. This synthetic strategy involved the preparation of 3-phosphate-substituted oxindole intermediates and SN1 reactions with haloid acids. This new procedure features mild reaction conditions, simple operation, good yield, readily available and inexpensive starting materials, and gram-scalability.

We proposed a novel photoinitiation system composed of photosensitizer and tyrosine-containing peptide, which could initiate radical photopolymerization of acrylamide in water in air. And, when the irradiation was extinguished, the formula with purged nitrogen kept polymerizing in the dark for a long time. The highlight of this system stems from the fact that after low-intensity irradiation as brief as 2 or 5 min, the generated radicals have long lifetime, allowing polymerization propagation in the dark to result in high molecular weight and high conversion. The dark polymerization might be ascribed to the protonation and the steric hindrance of polyacrylamide macroradicals, endowed by the tyrosine-containing peptide, preventing the biradical termination. And these behaviors of the investigated peptides were related to the location of the tyrosine residue on polypeptide chain. In addition, this novel photoinitiator can’t initiate dark polymerization of other water-soluble monomers, but can initiate dark copolymerization of acrylamide with these monomers, further indicating that the hydrogen bonding between acrylamide and polypeptide might be the key factor for dark polymerization. This novel system has potential applications in the preparation of biohydrogels.

A new P(OEt)3-mediated formal S–H bond-insertion reaction of isatins into thiols for the synthesis of valuable 3-sulfenylation oxindoles has been developed. This approach takes advantage of the unique reactivity of Kukhtin–Ramirez adducts to allow direct reductive S–H functionalization with commercially available and bench-stable starting materials.

An efficient stereoselective assembly strategy for the construction of pyrrolidin-2,3′-oxindole cis-fused phosphadihydrocoumarins was established. The process involves the condensation of O-vinylphosphonylated salicylaldehydes and 3-amino oxindoles followed by intermolecular cycloaddition with high diastereoselectivity and atom economy.

A water-soluble silk peptide (SP) was fractioned to a series of SP fractions with different molecular weight. The antioxidant activity of these fractions was investigated by the ABTS and DPPH assays, and the co-initiating ability of each fraction in type II photoinitiator was evaluated in photopolymerization of acrylamide, using camphorquinone as the sensitizer. Gel permeation chromatograph was used to investigate molecular weight distributions of SP fractions. The results showed that with the increase of the proportion of the component with molecular weight of about 200 in SP fractions, antioxidant activity and co-initiation ability became poor. Four essential amino acids, Ala, Gly, Ser and Tyr of SP and their respective pentapeptides were also assessed for these two functions. Among them, pentatyrosine exhibited the most excellent performance in two functions, which might be ascribed to its excellent electron/hydrogen donation capability. And pentaglycine had good behavior in these two functions, suggesting that the polypeptide chain was responsible for electron/hydrogen donation. By 1H NMR analysis, it was speculated that the photoinitiation active center was located on the methylene group of pentaglycine. The electron/hydrogen donor of SP is the inherent reason for antioxidant function and photoinitiation performance of SP.

An efficient synthetic strategy for anti-3,4-disubstituted phosphadihydrocoumarin compounds has been established by tandem aza-Michael–aldol-like annulations of tetrahydroisoquinolines with O-vinylphosphonylated salicylaldehydes as an aldo-vinyl bifunctional building block. This conversion was characterized by ‘green’ properties such as a step- and atom-economy, catalyst-free conditions, highly anti-selectivity­, and readily available starting materials.

A new rearrangement of isatin-derived N,N′-cyclic azomethine imines to afford intermediate 3-hydroxy-1H-pyrazole -substituted oxindole was found, and then Michael addition of them to a vinyl bisphosphonate ester provided 3,3-disubstituted oxindole-fused pyrazolidone derivatives containing bisphosphonates in the presence of the readily available DMAP. This transformation is particularly attractive due to features such as unexpected rearrangement, mild conditions, atom economy, the ready availability of the starting materials.

A metal-free direct sulfenylation of phenol and arylamine derivatives with various heterocyclic thiols and thiones using a cross dehydrogenative coupling protocol in water at room temperature has been developed. In addition, this chemical method has several advantages including odorless sulfur sources, good functional group tolerance, green solvent, and mild conditions, making it more environmentally friendly.

A concise, atom-economic, and highly regioselective synthetic strategy for the construction of several dinitrogen-fused heterocycles bearing bisphosphonates by 1,3-dipolar cycloaddition reaction of azomethine imines with tetraethyl vinylidene-1,1-bisphosphonate in the presence of CuI in toluene media has been developed. The targeted compounds were obtained in good yields and with excellent regioselectivity. This method for the synthesis of gem-bisphosphonates (BPs) is particularly attractive due to features such as low cost, mild conditions, atom economy, high stereoselectivity, and potential biological activity of the product.

A concise, atom-economic, and highly regio/stereoselective synthetic strategy was developed for the construction of phosphorus- and nitrogen-fused polycyclic skeleton derivatives. The one-pot, two-step, catalyst-free domino condensation/intramolecular cycloaddition reaction of various substituted 2-(vinylphosphoryloxy)benzaldehydes with pyrazolidin-3-one took place at room temperature. Three new bonds (C–C, 2 × C–N) and two new nitrogen and phosphorus heterocycles were simultaneously constructed. The reaction is particularly attractive due to features such as low cost, mild conditions, atom economy, high stereoselectivity, and potential biological activity of the product.

A one-pot, three-component condensation reaction of 8-quinolinol, 2-thiobarbituric acid and isatins or aldehydes in water to give novel barbituroquinoline derivatives for the first time, is described. The reaction is free of catalysts and toxic solvents, operating under mild conditions and allows for ease of product isolation, making it more environmentally friendly and suitable for large-scale operations.

Pyrrolizidine and coumarins both have biological activities, and their molecular skeletons are commonly found in several biomolecules and drug molecules. We have developed a catalyst-free, intramolecular 1,3-dipolar cycloaddition to synthesize phosphadihydrocoumarin-fused pyrrolizidine/pyrrolidine scaffolds with high stereoselectivity.

A one-pot, catalyst-free route to spiro[dihydroquinoline-naphthofuranone] compounds from isatins through ring-opening and cyclization processes in water is disclosed. Hydrogen-bonding effects of water proved to be the key factor to accelerate the transformation. In addition, the chemistry provides several advantages including that it is free of organic solvents, a simple operation, and a gram-scale synthesis and uses inexpensive reagents and a recyclable reaction medium.

A metal-free direct sulfenylation of phenol and arylamine derivatives with various heterocyclic thiols and thiones using a cross dehydrogenative coupling protocol in water at room temperature has been developed. In addition, this chemical method has several advantages including odorless sulfur sources, good functional group tolerance, green solvent, and mild conditions, making it more environmentally friendly.

4-Aryl-NH-1,2,3-triazoles are valuable compounds in organic chemistry and pharmaceutical chemistry. In this paper, we describe a novel multicomponent reaction of aldehydes, nitroalkanes, and sodium azide for the synthesis of 4-aryl-NH-1,2,3-triazoles. In this transformation, it was found that both the slow addition of nitroalkane and the presence of NaHSO3/Na2SO3 are advantageous to promote the reaction results. Additionally, a series of aldehydes and nitro compounds were investigated.

Various spiro[indole-pyrrolizine], spiro[indole-indolizine], and spiro[indole-pyrrolidine] gem-bisphosphonates were prepared by multicomponent reactions between isatins, tetraethyl vinylidenebis(phosphonate), and amino acids in the presence of montmorillonite. The one-pot reactions proceeded by 1,3-dipole cycloadditions of azomethine ylides formed in a decarboxylative manner. The proposed mechanism is in line with experimental data that confirmed that the azomethine ylide is formed in a decarboxylative manner; this provides new insight into the underlying mechanisms of such cycloadditions. The method has many notable features, such as a broad substrate scope, high efficiency, and high regioselectivity.

A convenient and efficient method for the synthesis of N-2-aryl 1,2,3-triazoles from α-arylhydrazonoketones under copper-catalyzed oxidative conditions has been developed. The tandem process comprises a condensation step of the carbonyl group with ammonium acetate and oxidative N–N bond formation in this transformation. The use of oxygen makes this transformation become more environmentally friendly. And various functional groups are well tolerated with the optimized reaction conditions.

A facile solvent- and catalyst-free method for the synthesis of a series of imidazo[1,2-a]pyridines in good to excellent yields by the condensation of 2-aminopyridines with α-bromoketones under microwave irradiation has been developed. The important features of this method are that it is reasonably fast, very clean, high yielding, simple workup and environmentally benign.

VBP reacts smoothly with L-proline and benzaldehyde derivatives at 80 °C in toluene catalyzed by cerium(IV) oxide (CeO2) to give the corresponding heterocyclic bisphosphonates in moderate yields (30–70%). A high regio-selectivity of the 1,3-dipole cycloaddition was observed. The structures of the targeted molecules are characterized by NMR (such as COSY, HSQC, and HMBC), IR and MS.

An efficient stereoselective method towards the construction of isoxazolidine- cis -fused phosphadihydrocoumarins frameworks involving an intermolecular 1,3-dipolar nitrone cycloaddition reaction utilizing O- vinylphosphonylated salicylaldehydes and N -substituted hydroxylamines in situ formation of Nitrone–Vinylphosphonate bifunctional intermediates under catalyst free condition have been described.

Straightforward and one-pot strategy to synthesize the bifunctional phosphorus Betti bases under solvent-free conditions via the condensation of 2-naphthol, aryl aldehydes and the diphenylphosphine oxide has been developed in the presence of p -toluenesulfonic acid for the first time. The entitled compounds are obtained in good yields and fully characterized by NMR, MS, IR and elemental analysis.

An environmentally benign four-component reaction in aqueous medium in the presence of cetyltrimethylammonium chloride (CTACl) has been developed for the synthesis of 6-amino-3-methyl-4-aryl-/1-phenyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile. The method presented is mild, environmentally friendly, inexpensive, and functionality tolerant and gives the products in good to excellent yields.

The three-component Kabachnik–Fields reaction of substituted salicylaldehydes, aromatic amine, and triphenyl phosphite in water was effectively catalyzed by p-toluenesulfonic acid to give various α-amino phosphonates in good yields. The catalyst is easily available and inexpensive, and the process is green and mild. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:110–115, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21071

4-Aryl-NH-1,2,3-triazoles are valuable compounds in organic chemistry and pharmaceutical chemistry. In this paper, we describe a novel multicomponent reaction of aldehydes, nitroalkanes, and sodium azide for the synthesis of 4-aryl-NH-1,2,3-triazoles. In this transformation, it was found that both the slow addition of nitroalkane and the presence of NaHSO3/Na2SO3 are advantageous to promote the reaction results. Additionally, a series of aldehydes and nitro compounds were investigated.

Various spiro[indole-pyrrolizine], spiro[indole-indolizine], and spiro[indole-pyrrolidine] gem-bisphosphonates were prepared by multicomponent reactions between isatins, tetraethyl vinylidenebis(phosphonate), and amino acids in the presence of montmorillonite. The one-pot reactions proceeded by 1,3-dipole cycloadditions of azomethine ylides formed in a decarboxylative manner. The proposed mechanism is in line with experimental data that confirmed that the azomethine ylide is formed in a decarboxylative manner; this provides new insight into the underlying mechanisms of such cycloadditions. The method has many notable features, such as a broad substrate scope, high efficiency, and high regioselectivity.

Straightforward and one-pot strategy to synthesize the bifunctional phosphorus Betti bases under solvent-free conditions via the condensation of 2-naphthol, aryl aldehydes and the diphenylphosphine oxide has been developed in the presence of p -toluenesulfonic acid for the first time. The entitled compounds are obtained in good yields and fully characterized by NMR, MS, IR and elemental analysis.

A convenient and efficient method for the synthesis of N-2-aryl 1,2,3-triazoles from α-arylhydrazonoketones under copper-catalyzed oxidative conditions has been developed. The tandem process comprises a condensation step of the carbonyl group with ammonium acetate and oxidative N–N bond formation in this transformation. The use of oxygen makes this transformation become more environmentally friendly. And various functional groups are well tolerated with the optimized reaction conditions.

PurposeTo analyse the diagnostic signs present in slices of human breast tumour specimens using synchrotron radiation phase-contrast imaging computed tomography (PCI-CT) for the first time and assess the feasibility of this technique for clinical applications.Materials and methodsThe ethics committee of our university and relevant clinical hospital approved this prospective study, and written informed consent was obtained from all patients. PCI-CT of human breast tumour specimens with synchrotron radiation was performed at the Shanghai Synchrotron Radiation Facility (SSRF). A total of 14 specimens of early-stage carcinomas and 8 specimens of adenomas were enrolled. Based on raw data reconstruction, the diagnostic signs present in the slices were analysed and correlated with histopathology. We proposed a criterion for clinical diagnosis according to the evaluated signs and the Breast Imaging Reporting and Data System (BI-RADS) for reference. The criterion was then assessed by clinicians in a double-blind method. Finally, descriptive statistics were evaluated, depending on the assessment results.ResultsThe 14 carcinoma specimens and 8 adenoma specimens were diagnosed as malignant and benign tumours, respectively. The total coincidence rate was 100%.ConclusionOur study results demonstrate that the X-ray diagnostic signs observed in the specimen slices and the criterion used for clinical diagnosis were accurate and reliable. The criterion based on signs analysis can be used to differentiate early-stage benign or malignant tumours. As a promising imaging method, PCI-CT can serve as a possible and feasible supplement to BI-RADS in the future.

Azomethine ylides generated in situ from L-proline (II) and aryl aldehydes (III) add regioselectively to VBP (I) to give the corresponding heterocyclic bisphosphonates (IV) as a mixture of diastereomers.

A highly efficient, catalyst-free, and regioselective synthesis of structurally diverse spirooxindole-fused phosphorous heterocycle derivatives was constructed in good yields by means of a three-component domino reaction of isatins, dichlorophenylphosphine or phenyl phosphorodichloridite, and o-aminophenol in tetrahydrofuran reflux. The advantages of this method include high efficiency, mild reaction conditions, and environmentally benign reagents. These spirooxindole-fused phosphorous heterocycles are promising candidates for drug discovery.

A simple, novel, and convenient synthesis of analogs of aminomethylene gem‐diphosphonic acids in one‐pot from primary and secondary amines in moderate yields was reported without catalyst.

A simple, expeditious and convenient synthesis of aminomethylene gem-diphosphonic acid derivatives in one-pot reaction using ketones, hydroxylamine hydrochloride, phosphorus trichloride and water as starting materials in the presence of pyridine via Beckmann rearrangement is described in the modest yields.

An environmentally benign four-component reaction in aqueous medium in the presence of cetyltrimethylammonium chloride (CTACl) has been developed for the synthesis of 6-amino-3-methyl-4-aryl-/1-phenyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile. The method presented is mild, environmentally friendly, inexpensive, and functionality tolerant and gives the products in good to excellent yields.

The title compounds (IV) are obtained in a three-component reaction of substituted salicylaldehydes, aromatic amines, and triphenyl phosphite under mild and green reaction conditions.