介绍了Kirk—Othmer Encyclopedia of Chemical Technology（化工技术百科全书）（第五版）电子图书网络版数据库，并对该数据库使用方法和检索途径作出了说明，且结合实例简单地介绍了该数据库的检索方法。

Kirk-Othmer Encyclopedia of Chemical Technology数据库介绍及实例

A new iron(III) halide-promoted aza-Prins cyclization between γ,δ-unsaturated tosylamines and aldehydes provides six-membered azacycles in good to excellent yields. The process is based on the consecutive generation of γ-unsaturated-iminium ion and further nucleophilic attack by the unsaturated carbon−carbon bond. Homoallyl tosylamine leads to trans-2-alkyl-4-halo-1-tosylpiperidine as the major isomer. In addition, the alkyne aza-Prins cyclization between homopropargyl tosylamine and aldehydes gives 2-alkyl-4-halo-1-tosyl-1,2,5,6-tetrahydropyridines as the only cyclic products. The piperidine ring is widely distributed throughout Nature, e.g., in alkaloids,1 and is an important scaffold for drug discovery, being the core of many pharmaceutically significant compounds.2,3 The syntheses of these type of compounds have been extensively studied in the development of new drugs containing six-membered-ring heterocycles.4 Reactions between N-acyliminium ions and nucleophiles, also described as amidoalkylation or Mannich-type condensations, have been frequently used to introduce substituents at the R-carbon of an amine.5 There are several examples that involve an intramolecular attack of a nucleophilic olefin into an iminium cation for the construction of a heterocyclic ring system.6 Traditionally, the use of hemiaminals or their derivatives as precursors of N-acyliminium intermediates has been a common two-step strategy in these reactions.6a Among this type of cyclization is the aza-Prins cyclization,7 which uses alkenes as intramolecular nucleophile. However, cy† X-ray analysis. E-mail address: malopez@ull.es. (1) (a) Fodor, G. B.; Colasanti, B. Alkaloids: Chemical and Biological PerspectiVes; Pelletier, S. W., Ed.; Wiley: New York, 1985; Vol. 23, pp 1-90. (b) Baliah, V.; Jeyarama, R.; Chandrasekaran, L. Chem. ReV. 1983, 83, 379-423. (2) Watson, P. S.; Jiang, B.; Scott, B. Org. Lett. 2000, 2, 3679-3681. (3) Horton, D. A.; Bourne, G. T.; Smythe, M. L. Chem. ReV. 2003, 103, 893-930. (4) Buffat, M. G. P. Tetrahedron 2004, 60, 1701-1729 and references therein. (5) Speckamp, W. N.; Moolenaar, M. J. Tetrahedron 2000, 56, 3187- 3856 and references therein. (6) (a) Hiemstra, H.; Speckamp, W. N. In ComprehensiVe Organic Synthesis; Trost, B. M., Fleming, O., Heathcock, C. H., Eds.; Pergamon: New York, 1991; Vol. 2, pp 1047-1081. (b) Speckamp, W. N.; Hiemstra, H. Tetrahedron 1985, 41, 4367-4416. (7) (a) Dobbs, A. P.; Guesne, S. J. J.; Hursthouse, M. B.; Coles, S. J. Synlett 2003, 11, 1740-1742. (b) Dobbs, A. P.; Guesne, S. J. J.; Martinove, S.; Coles, S. J.; Hursthouse, M. B. J. Org. Chem. 2003, 68, 7880-7883. (c) Hanessian, S.; Tremblay, M.; Petersen, F. W. J. Am. Chem. Soc. 2004, 126, 6064-6071 and references therein. (d) Dobbs, A. P.; Guesne, S. J. Synlett 2005, 13, 2101-2103. ORGANIC

Iron-Catalyzed Reactions in Organic Synthesis

Iron Catalysis in Organic Synthesis

The thermal and physicochemical properties of protic ionic liquids (PILs) are reported. It is highly evident that there has been an extensive range of alkylammonium, imidazolium, and heterocyclic cations paired with many organic and inorganic anions that have been employed to prepare PILs. There has been strong interest in modifying the properties of PILs through the addition of water or other molecular solvents. For many applications, the presence of some water in the PILs is not detrimental, and instead leads to enhanced solvent properties such as lower viscosity, higher conductivities, and lower melting points. It remains an issue of definition though of how to refer to these resulting protic solutions. There is also an ongoing difficulty surrounding how to describe the proton activity in the PILs, analogous to pH in aqueous systems. For a broad range of applications, it has been reported that the acidity/basicity of the PIL or PIL-solvent system is crucial for their beneficial properties. It is expected that the fundamental properties of PILs will continue to be explored, along with continued interest in many existing and new applications, such as in electrochemistry, organic and inorganic synthesis, and biological applications. In particular, there has been a significant interest in a broad- range of PILs for use as electrolytes and incorporation in polymer electrolytes for fuel cells, and other energy storage devices.

Protic Ionic Liquids: Evolving Structure–Property Relationships and Expanding Applications

https://bioone.org/journals/harvard-papers-in-botany/volume-13/issue-2/1043-4534-13.2.299/Flora-of-China/10.3100/1043-4534-13.2.299.pdf

Flora of China

A simple and efficient one-pot synthesis of 1,4-dihydropyridine derivatives was achieved via condensation of methyl acetoacetate or ethyl propiolate with various alkyl and aryl aldehydes and ammonium acetate at 80 °C under solvent free conditions with good to excellent yields.

An Efficient Procedure for the Synthesis of Hantzsch 1,4-Dihydropyridines Under Mild Conditions

An efficient and rapid synthesis of 2,3-disubstituted-4(3H)quinazolinones by condensation of 2-aminobenzamide (substituted anthraniamides) with orthoesters in the presence of K-10 clay under solven...

Montmorillonite K-10 catalysed solvent-free synthesis of 2,3-disubstituted-4(3H)quinazolinones under microwave irradiation:

Background: The effect of antioxidant therapy on sperm DNA fragmentation index (DFI) and achieving natural pregnancy were under debate. Very few studies have showed the rate of pregnancy rate after the antioxidant therapy due to ethical and technical limitations. Objective: The aim of this cohort study was to determine the improvement rate of sperm DFI and natural pregnancy rate after the antioxidant therapy in infertile men. Materials and Methods: 1645 infertile men were subjected for this study from May 2015 to December 2017. The Spermogram and sperm DFI were assessed using World Health Organization (WHO) 2010-based protocols and sperm chromatin structure assay (SCSA), respectively, in sperm samples before and after antioxidant therapy. Results: The total sperm DFI improvement rate was 38.9% in the total population. Sperm DFI improvement had close correlation with total motility (r= 0.731, p= 0.001) and progressive motility improvement (r= 0.885, p= 0.001); 16.8% of individuals who completed antioxidant therapy for nine months achieved natural pregnancy. Conclusion: The results of the current study suggested that SCSA along with spermogram might be a suitable option for the evaluation of fertility potential. In addition, antioxidant therapy may be useful for men with high levels of sperm DFI. However, the rate of pregnancy was still low and other treatment protocols such as assisted reproductive technology may be necessary.

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Effect of antioxidant therapy on the sperm DNA integrity improvement; a longitudinal cohort study.

Industrial Crops and Products

The synthesis of some tetrahydropyrazolopyridine derivatives has been described by a one-pot 2A + 2B + C + D four component reaction of a 1,3-dicarbonyl compound, an aldehyde, hydrazine and ammonium acetate in ethanol as a green media under catalyst-free condition.

Peyman Salehi

Papers

An Efficient Procedure for the Synthesis of Hantzsch 1,4-Dihydropyridines Under Mild Conditions

Montmorillonite K-10 catalysed solvent-free synthesis of 2,3-disubstituted-4(3H)quinazolinones under microwave irradiation:

Effect of antioxidant therapy on the sperm DNA integrity improvement; a longitudinal cohort study.

Industrial Crops and Products

An efficient synthesis of tetrahydropyrazolopyridine derivatives by a one-pot tandem multi-component reaction in a green media