628-17-1Relevant academic research and scientific papers
A mild and highly chemoselective iodination of alcohol using polymer supported DMAP
Das, Diparjun,H Anal, Jasha Momo,Rokhum, Lalthazuala
, p. 1695 - 1701 (2017/03/08)
The synthesis of organic compounds using polymer supported catalysts and reagents, where the required product is always in solution, has been of great interest in recent years, both in industries and academia especially in pharmaceutical research. Here, a simple and efficient method for conversion of alcohols into their iodides in high yield using polymer supported 4-(Dimethylamino)pyridine (DMAP) is described. Polymer supported DMAP is used in catalytic amount and is recovered and reused several times. Additionally, this method is highly chemoselective. [Figure not available: see fulltext.]
A mild method for the replacement of a hydroxyl group by halogen. 1. Scope and chemoselectivity
Munyemana, Fran?ois,George, Isabelle,Devos, Alain,Colens, Alain,Badarau, Eduard,Frisque-Hesbain, Anne-Marie,Loudet, Aurore,Differding, Edmond,Damien, Jean-Marie,Rémion, Jeanine,Van Uytbergen, Jacqueline,Ghosez, Léon
, p. 420 - 430 (2015/12/31)
α-Chloro-, bromo- and iodoenamines, which are readily prepared from the corresponding isobutyramides have been found to be excellent reagents for the transformation of a wide variety of alcohols or carboxylic acids into the corresponding halides. Yields are high and conditions are very mild thus allowing for the presence of sensitive functional groups. The reagents can be easily tuned allowing therefore the selective monohalogenation of polyhydroxylated molecules. The scope and chemoselectivity of the reactions have been studied and reaction mechanisms have been proposed.
Simple synthesis of fresh alkyl iodides using alcohols and hydriodic acid
Klein, Suzane M.,Zhang, Cungen,Jiang, Yu Lin
, p. 2638 - 2641 (2008/09/19)
A simple synthesis of fresh alkyl iodides using alcohols and hydriodic acid (HI) is reported. The alkyl iodides were obtained in quick and easy work-up with good to excellent yields (66-94%) and very high purities (97-99%). Freshly prepared iodomethane and 1-iodobutane were applied to synthesize biologically relevant 3,7-dimethyladenine and 9-butyladenine, which were characterized thoroughly using 1D and 2D NMR, individually.
Direct bromination and iodination of non-activated alkanes by hypohalite reagents
Montoro, Raul,Wirth, Thomas
, p. 1473 - 1478 (2007/10/03)
The direct functionalisation of alkanes through bromination and iodination has been successfully achieved. The combination of stoichiometric mixtures of elemental halogen and sodium alkoxides leads to the formation of alkyl hypobromites and hypoiodites as reagents. The halogenation occurs without external photostimulation under thermal reaction conditions. Georg Thieme Verlag Stuttgart.
Direct halogenation of alcohols and their derivatives with tert-Butyl halides in the ionic liquid [pmIm]Br under sonication conditions - A novel, efficient and green methodology
Ranu, Brindaban C.,Jana, Ranjan
, p. 755 - 758 (2007/10/03)
A novel halogenating reagent system for direct halogenation of alcohols has been developed. tert-Butyl bromide, chloride and iodide in combination with the ionic liquid [pmIm]Br have been found to convert alcohols into the corresponding bromides, chlorides and iodides under sonication conditions (or heating) in good yields. Although a variety of primary and secondary alcohols participated in this reaction without any difficulty, tertiary alcohols remained inert. Several alcohol derivatives such as OTMS, OTBDMS, OAc, OTS and OTHP are also transformed into the corresponding halides in one-pot fashion by this procedure. A plausible rationale for this transformation is also presented. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
Direct Iodination of Alkanes
Montoro, Raul,Wirth, Thomas
, p. 4729 - 4731 (2007/10/03)
(Matrix presented) A cheap and efficient iodination of hydrocarbons can be achieved by generating tert-butyl hypoiodite from iodine and sodium tert-butoxide. The alkane is reactant and solvent, and this metal-free process provides a clean solution for their direct iodination.
Bicyclic imidazolyl derivatives as phosphodiesterase inhibitors, pharmaceutical compositions and method of use
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, (2008/06/13)
The present invention provides for compounds having the following Formulae I-III, and The compounds of the present invention are useful in the treatment of a variety of disease such as glaucoma, sexual dysfunction, asthma and cardiovascular disorders such as stable-, unstable- and variant-angina, hypertension, pulmonary hypertension, congestive heart failure, atherosclerosis, and thrombosis.
Primary and secondary 5-(alkyloxy)thianthrenium perchlorates. Characterization with 1H NMR spectroscopy, reactions with iodide and bromide ion, and thermal decomposition in solution
Zhao, Wenyi,Shine, Henry J.
, p. 695 - 702 (2007/10/03)
A series of 5-(alkyloxy)thianthrenium perchlorates has been made in which the alkyl group is primary (1a-1p) and secondary (2a-2g). Preparations were carded out by reaction of the corresponding alkanol with thianthrene cation radical perchlorate in CH2Cl2 solution followed by precipitation of the perchlorate salt with dry ether. 1H NMR spectroscopy reveals that the presence of a stereogenic center in the alkyl group causes inequivalence in the ordinarily paired protons (e.g., H-4, H-6) of the thianthrenium ring. Reaction of iodide and bromide ion with primary alkyl-group compounds (e.g., methyl, ethyl, propyl, butyl) gave the alkyl halide in very good yield and by a second-order kinetic displacement. The second product was thianthrene 5- oxide (ThO). Rate constants for some of these reactions are reported. Reaction of secondary alkyl group compounds (e.g., 2-propyl, 2-pentyl, 2- hexyl, and 3-hexyl) with iodide ion gave good yields of alkyl iodide but also increasing evidence for a side reaction at the sulfonium sulfur, leading to I2, thianthrene, and secondary alkanol. Decomposition of some compounds at 100°C in solution (acetonitrile or 1,2-dichloroethane) was studied and gave alkene(s) and ThO.
Radical reactions in the radiolysis of cyclopentane
Wojnarovits,LaVerne
, p. 3168 - 3172 (2007/10/02)
The end products produced in the γ-radiolysis of cyclopentane have been measured at very low total doses (25-50 krad). Iodine scavenging techniques in solutions of 0.1-30 mM were used to elucidate radical yields and reaction mechanisms. The yields of the main radical species were found to be as follows: cyclopentyl, 4.9; 1-pentyl, 0.2; 3-cyclopentenyl, 0.07; H atom, 1.3 radical/100 eV. The change in yields from neat cyclopentane to 0.1 mM iodine solution suggests that about 79% of the cyclopentyl radicals escape the spur and react in the bulk medium with a disproportionation to combination ratio of 0.97. Radical precursors account for about 50% of the total end product yield, which is much smaller than found in the radiolysis of cyclohexane or cyclooctane. The radiolysis mechanism for cyclopentane is discussed and compared to those for cyclohexane and cyclooctane.
Chiral Organometallic Reagents, XI. Stereoselective Exchange of Diastereotopic Iodine Atoms by Magnesium in 3-Alkoxy-1,1-diiodoalkanes
Hoffmann, Reinhard W.,Kusche, Andreas
, p. 1311 - 1316 (2007/10/02)
α-Iodoalkylmagnesium species were generated by reaction of 3-oxygenated 1,1-diiodoalkanes with isopropylmagnesium halides at -78 deg C.The resulting magnesium carbenoids were found to be configurationally stable at temperatures up to -20 deg C and were trapped by benzaldehyde or allyl iodide at low temperatures.Stereoselectivity on exchange of the diastereotopic iodine atoms in 3 was found to be low. - Key Words: 1-Iodoalkylmagnesium reagents / Stability, configurational
