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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.

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.

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.

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.

Background: Mechanical system with imperfect or misalignment of X-ray phase contrast imaging (XPCI) components causes projection data misplaced, and thus result in the reconstructed slice images of computed tomography (CT) blurred or with edge artifacts. So the features of biological microstructures to be investigated are destroyed unexpectedly, and the spatial resolution of XPCI image is decreased. It makes data correction an essential pre-processing step for CT reconstruction of XPCI. Methods: To remove unexpected blurs and edge artifacts, a mathematics model for in-line XPCI is built by considering primary geometric parameters which include a rotation angle and a shift variant in this paper. Optimal geometric parameters are achieved by finding the solution of a maximization problem. And an iterative approach is employed to solve the maximization problem by using a two-step scheme which includes performing a composite geometric transformation and then following a linear regression process. After applying the geometric transformation with optimal parameters to projection data, standard filtered back-projection algorithm is used to reconstruct CT slice images. Results: Numerical experiments were carried out on both synthetic and real in-line XPCI datasets. Experimental results demonstrate that the proposed method improves CT image quality by removing both blurring and edge artifacts at the same time compared to existing correction methods. Conclusions: The method proposed in this paper provides an effective projection data correction scheme and significantly improves the image quality by removing both blurring and edge artifacts at the same time for in-line XPCI. It is easy to implement and can also be extended to other XPCI techniques.

Background In recent years, X-ray phase-contrast imaging techniques have been extensively studied to visualize weakly absorbing objects. One of the most popular methods for phase-contrast imaging is in-line phase-contrast imaging (ILPCI). Combined with computed tomography (CT), phase-contrast CT can produce 3D volumetric images of samples. To date, the most common reconstruction method for phase-contrast X-ray CT imaging has been filtered back projection (FBP). However, because of the impact of respiration, lung slices cannot be reconstructed in vivo for a mouse using this method. Methods for reducing the radiation dose and the sampling time must also be considered. Methods This paper proposes a novel method of in vivo mouse lung in-line phase-contrast imaging that has two primary improvements compared with recent methods: 1) using a compressed sensing (CS) theory-based CT reconstruction method for the in vivo in-line phase-contrast imaging application and 2) using the breathing phase extraction method to address the lung and rib cage movement caused by a live mouse’s breathing. Results Experiments were performed to test the breathing phase extraction method as applied to the lung and rib cage movement of a live mouse. Results with a live mouse specimen demonstrate that our method can reconstruct images of in vivo mouse lung. Conclusions The results demonstrate that our method could deal with vivo mouse’s breathing and movements, meanwhile, using less sampling data than FBP while maintaining the same high quality.