- Molecular iodine/DMSO mediated oxidation of internal alkynes and primary alcohols using a one-pot, two step approach towards 2,4,5-trisubstituted imidazoles: Substrate scope and mechanistic studies
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An efficient, eco-friendly and practical oxidation of internal alkynes and primary alcohols as key steps towards the synthesis of 2,4,5-trisubstituted imidazoles is reported. This green synthetic methodology employed an acid and metal-free molecular iodine/DMSO system, to afford a variety of substituted imidazoles in moderate to good yields, with a range of functionalities tolerated. Mechanistic studies revealed two distinct oxidation pathways, which ultimately form the diketone and aldehyde that serve as key intermediates in the multicomponent domino synthesis.
- Jeena, Vineet,Naidoo, Shivani
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supporting information
(2020/02/15)
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- High yield preparation method of selexipag intermediate compound under middle conditions
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The invention relates to a high yield preparation method of a selexipag intermediate compound under middle conditions. According to the method, styracitol and halogen acid carry out halogenation reactions, and the reaction product and N-aminoacetyl-N-isopropyl n-butanol carry out condensation, ammoxidation, and ring forming reactions to obtain 2-(N-isopropyl-N-4-hydroxylbutyl)amino-5,6-diphenylpyrazine. The compound can be used to prepare selexipag. The raw materials are cheap and easily available, the operation is simple, convenient and safe, the reaction selectivity is good, the yield and purity are high, and the cost is low.
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Paragraph 0059-0060
(2019/03/15)
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- Iodine/DMSO promoted oxidation of benzylic Csp3–H bonds to diketones – A mechanistic investigation
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This article describes a mechanistic investigation into the I2/DMSO mediated benzylic Csp3–H oxidation of an α-methylene ketone. The electron paramagnetic resonance (EPR) spectrum centred at g = 2.0011 supports the involvement of iodine and benzylic radicals, as the α-iodinated compound 2-iodo-1,2-diphenylethanone was isolated as a key reactive intermediate. The oxidation reaction relies, primarily, on DMSO as a source of oxygen in benzil, proven by the reaction of benzyl phenyl ketone with diphenyl sulfoxide (DPSO).
- Jayram, Janeeka,Xulu, Bheki A.,Jeena, Vineet
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- Three-component access to pyrroles promoted by the CAN-silver nitrate system under high-speed vibration milling conditions: A generalization of the Hantzsch pyrrole synthesis
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A sequential multicomponent process involving the high-speed vibration milling of ketones with N-iodosuccinimide and p-toluenesulfonic acid, followed by addition of a mixture of primary amines, β-dicarbonyl compounds, cerium(iv) ammonium nitrate and silver nitrate afforded polysubstituted, functionalized pyrroles. This one-pot, solid-state process can be considered as the coupling of an α-iodoketone preparation with a general version of the classical Hantzsch pyrrole synthesis.
- Estevez, Veronica,Villacampa, Mercedes,Menendez, J. Carlos
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p. 591 - 593
(2013/02/22)
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- Iodination of alcohols over Keggin-type heteropoly compounds: A simple, selective and expedient method for the synthesis of alkyl iodides
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Different catalysts derived from Keggin-type heteropoly compounds were prepared and their catalytic activities have been compared in the iodination of benzyl alcohol with KI under mild reaction conditions. A high catalytic activity was found over tungstophosphoric acid supported on silica and titania. The effect of catalyst loading, iodine source and the nature of substituents on the aromatic ring of benzyl alcohol were investigated. Finally, several competitive reactions were studied between structurally diverse alcohols. This protocol provides a mild and expedient way for the conversion of various alcohols to their corresponding alkyl iodides with high selectivity.
- Rafiee, Ezzat,Mahdavia, Houri,Joshaghani, Mohammad
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experimental part
p. 135 - 140
(2011/06/09)
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- IBX/I2-mediated oxidation of alkenes and alkynes in water: a facile synthesis of α-iodoketones
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The conversion of alkenes into α-iodoketones has been achieved in good yields and with high regioselectivity by means of iodohydrin formation and subsequent oxidation with 2-iodoxybenzoic acid (IBX) under mild conditions. Aromatic alkynes are also convert
- Yadav, Jhillu S.,Subba Reddy, Basi V.,Singh, Ashutosh P.,Basak, Ashok K.
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scheme or table
p. 5880 - 5882
(2009/04/04)
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- Highly efficient and clean method for direct α-iodination of aromatic ketones
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Under neutral reaction conditions, aromatic ketones were transformed into the corresponding α-iodo ketones in high yields by the combination of copper(II) oxide and iodine. The reaction mechanism showed that copper(II) oxide played multiple roles through random self-sorting. Georg Thieme Verlag Stuttgart.
- Yin, Guodong,Gao, Meng,She, Nengfang,Hu, Shengli,Wu, Anxin,Pan, Yuanjiang
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p. 3113 - 3116
(2008/09/16)
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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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- CHEMISTRY OF α-NITROEPOXIDES: SYNTHESIS OF USEFUL INTERMEDIATES VIA NUCLEOPHILIC RING OPENING OF α-NITROEPOXIDES
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Various α-nitroepoxides are converted into corresponding 1,2-diketones via two different ways of ring opening viz. with Pd(O) and with DMSO/BF3*EtO2 (or ClSiMe3).In addition to this, a variety of nucleophiles are reacted with α-nitrocyclopentene oxide 6 and α-nitrocyclohexene oxide 7 to form the corresponding α-substituted ketones which are useful intermediates in organic synthesis.Two of the products so obtained viz. 32 and 33 are also transformed further into optically active thialactones 38 and 39 respectively via baker's yeast reduction followed by lactonisation.
- Vankar, Yashwant D.,Shah, Kavita,Bawa, Anita,Singh, Surendra P.
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p. 8883 - 8906
(2007/10/02)
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- A Facile Conversion of α-Nitroepoxides into 1,2-Diones and α-Iodoketones
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1,2-Diones and α-iodoketones have been prepared from α-nitroepoxides by treatment with DMSO/BF3*Et2O followed by Et3N and BF3*Et2O/NaI respectively.
- Vankar, Yashwant D.,Saksena, Rajendra K.,Bawa, Anita
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p. 1241 - 1244
(2007/10/02)
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