- Oxygen Effect in the Iodo Lactonization of Unsaturated Carboxylic Acids Leading to 7- to 12-Membered Ring Lactones
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The reaction of ω-alkenoic acids with bis(sym-collidine)iodine(I) hexafluorophosphate led to (iodomethyl) ε-caprolactones in good yields (49-75percent) and medium ring iodo lactones in low yields (4-5percent).The latter compounds have been obtained after introduction of an oxygen atom in the carbon chain.The position of the oxygen appeared important.This oxygen effect was explained by the stabilization of the intermediate iodonium ion by the oxygen atom.
- Simonot, Bruno,Rousseau, Gerard
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- Preparation of 5-methylfurfural from starch in one step by iodide mediated metal-free hydrogenolysis
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Starch is available in large quantities and at cheap price, especially that from stale rice, root and tuber crops, etc., which makes it desirable for conversion to value-added products. A metal-free approach to convert starch to 5-methylfurfural (5-MF) using hydrochloric acid, sodium iodide and hydrogen in a biphasic solvent system has been developed. 5-MF is an important fine chemical, widely used in food, medicine, pesticides, cosmetics and other industries, and is also considered to be an important bio-gasoline precursor. I- has superior nucleophilic substitution properties and high reactivity towards C-O bond cleavage, which is crucial for this transformation. Under optimal reaction conditions, 38.0% of 5-MF and 45.6% of total organic products can be obtained from starch with 22.5% levulinic acid as the main side product. Besides, 80.8% 5-MF can be directly obtained from 5-hydroxymethylfurfural (HMF) through the same process. To the best of our knowledge, this is the first reported example of a metal-free process to convert starch and HMF directly to 5-MF. The reaction mechanism was well studied. The catalyst system was proved to be stable and was recycled five times without loss of activity.
- Peng, Yang,Li, Xianghua,Gao, Tian,Li, Teng,Yang, Weiran
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- An efficient and selective method for the iodination and bromination of alcohols under mild conditions
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A straightforward and effective procedure for the conversion of a variety of alcohols into the corresponding alkyl iodides and bromides is described using KX/P2O5 (X = I, Br). The reactions were easily carried out in acetonitrile under mild conditions. Using this method, the selective conversion of benzylic alcohols in the presence of aliphatic alcohols was achieved.
- Khazdooz, Leila,Zarei, Amin,Aghaei, Hamidreza,Azizi, Ghobad,Gheisari, Mohammad Mehdi
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p. 168 - 171
(2015/12/30)
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- NOVEL ANTIVIRAL PYRROLOPYRIDINE DERIVATIVES AND METHOD FOR PREPARING THE SAME
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The present invention relates to a pyrrolopyridine derivative represented by the Chemical Formula I, and a racemate or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, and relates to an antiviral composition including the same as an active ingredient. The compound of the Chemical Formula I has excellent antiviral activity and selectivity for wild type and resistant HIV-1, and thereby is useful as a therapeutic agent for acquired immune deficiency syndrome (AIDS).
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Paragraph 0447; 0448
(2014/09/16)
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- NOVEL ANTIVIRAL PYRROLOPYRIDINE DERIVATIVE AND A PRODUCTION METHOD FOR SAME
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The present invention relates to a pyrrolopyridine derivative represented by the Chemical Formula I, and a racemate or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, and relates to an antiviral composition including the same as an active ingredient. The compound of the Chemical Formula I has excellent antiviral activity and selectivity for wild type and resistant HIV-1, and thereby is useful as a therapeutic agent for acquired immune deficiency syndrome (AIDS).
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Paragraph 0428; 0429
(2014/12/09)
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- An alternative method for the highly selective iodination of alcohols using a CsI/BF3·Et2O system
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A variety of allylic and benzylic alcohols have been converted into the corresponding iodides using cesium iodide (CsI) in the presence of boron trifluoride etherate (BF3·Et2O) in acetonitrile under mild conditions.
- Hayat, Safdar,Atta-Ur-Rahman,Khan, Khalid Mohammed,Choudhary, M. Iqbal,Maharvi, Ghulam Murtaza,Zia-Ullah,Bayer, Ernst
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p. 2531 - 2540
(2007/10/03)
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- An expedient and highly selective iodination of alcohols using a KI/BF3·Et2O system
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Alkyl iodides are prepared in high yields by treatment of allylic and benzylic alcohols with an equimolar amount of KI in the presence of BF3·Et2O in dioxane under mild conditions.
- Bandgar,Sadavarte,Uppalla
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p. 951 - 953
(2007/10/03)
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- Halogenation of benzyl- and (heteroaromatic methyl)cobaloximes: Direct competition between ring halogenation and cobalt-carbon bond cleavage
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(4-Acetamidobenzyl)- and (4-(dimethylamino)benzyl)cobaloximes react rapidly with low concentrations of chlorine and bromine in acetic acid or chloroform at room temperature under nitrogen. Both ring-halogenated organometallic products and direct Co-C cleavage products are formed. However, (4-methoxybenzyl)cobaloxime forms 4-methoxy-2-halotoluene as the exclusive product. (3-Methylbenzyl)cobaloxime undergoes a substantial proportion of ring substitution by both Br2 and Cl2 in competition with the cleavage of the Co-C bond. (3-Methoxybenzyl)cobaloxime forms only the ring-substituted organometallic product. A remarkable difference in reactivity between 2- and 3-isomers of the (thienylmethyl)- and (furylmethyl)cobaloximes is observed; for example, Co-C cleavage is the primary process in furfuryl- and (2-thienylmethyl)cobaloximes whereas ring halogenation occurs much faster in the 3-isomer. The results are discussed in terms of a σ-π delocalization phenomenon by which the electronic effect of a substituent in the benzyl group is effectively transmitted to the Co-C bond reactivity. The substituent effect of the metallomethyl group -CH2Co(dmgH)2py is found to be more than that of the methoxy group. The mechanism of the Co-C cleavage is described.
- Gupta,Kumar, Manoj,Roy, Sujit
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