- Aqueous bile salt accelerated cascade synthesis of 1,2,3-triazoles from arylboronic acids
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A facile, efficient and mild copper catalyzed strategy for cascade synthesis of various 1,4-disubstituted 1,2,3-triazoles from arylboronic acids, sodium azide and alkynes was developed by using aqueous bile salt NaDC solution as an accelerating medium. Lo
- Garg, Anirban,Ali, Abdul Aziz,Damarla, Krishnaiah,Kumar, Arvind,Sarma, Diganta
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supporting information
p. 4031 - 4035
(2018/10/09)
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- Photochemical C–H Activation: Generation of Indole and Carbazole Libraries, and First Total Synthesis of Clausenawalline D
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The photolysis of N-aryltriazoles and N-arylbenzotriazoles leads to indoles and carbazoles, respectively. Because libraries of triazoles can be accessed rapidly, for example by the copper-catalyzed [3+2] cycloaddition reaction between alkynes and azides, this reaction allows the preparation of indoles in a single operation, by the simultaneous photolysis of the precursor library. As an example of such a synthesis of carbazoles, we prepared for the first time clausenawalline D, an antimalarial alkaloid that was recently isolated.
- Alimi, Isak,Remy, Richard,Bochet, Christian G.
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p. 3197 - 3210
(2017/06/21)
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- An efficient and recyclable thiourea-supported copper(i) chloride catalyst for azide-alkyne cycloaddition reactions
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A reaction between two equivalents of bulky thiourea, i.e., 1,3-bis(2,6-dimethylphenyl)thiourea (L) [L = (ArNH)2C = S; Ar = 2,6-Me2C6H3], and CuCl2 or CuCl in THF solvent afforded a bulky thiourea-sta
- Barman, Milan Kr.,Sinha, Ashish Kumar,Nembenna, Sharanappa
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p. 2534 - 2541
(2016/05/19)
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- Lewis base catalyzed aerobic oxidative intermolecular azide-zwitterion cycloaddition
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The discovery of a novel aerobic oxidative intermolecular azide-zwitterion reaction catalyzed by an organocatalyst is presented. It is demonstrated that the merger of the Lewis base 1,8-diazabicyclo[5.4.0]undec-7-ene and electrondeficient olefins generates reactive zwitterion intermediates, which readily participate in cycloaddition reactions with an array of azides, thus providing facile entry to fully or highly substituted 1,2,3-triazole frameworks. The reaction features an excellent substrate scope, and the products are obtained with high yields and excellent regioselectivities. It is demonstrated that some of these products can be transformed into pharmaceutically important agents. In addition to the experimental results, a detailed mechanistic survey is also provided, including MS studies rationalizing the origin of regioselective control.
- Li, Wenjun,Wang, Jian
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supporting information
p. 14186 - 14190
(2015/02/05)
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- Synthesis and chemiluminescent activity of pyridazino[4,5-b]indole-1,4(2H,3H)-diones
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Substituted and non-substituted anilines were transformed to the corresponding triazole derivatives, which were converted to dimethyl indole-2,3-dicarboxylates by photocyclization. The reaction of diester with hydrazine hydrate gave 1,2,3,4-tetrahydro-5H-
- Kurumi, Masateru,Sasaki, Kenji,Takata, Hiroko,Nakayama, Taiji
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p. 2809 - 2819
(2007/10/03)
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- 111. Three-component reactions with sterically crowded 2,2,4,4-tetramethyl-3-thioxocyclobutanone, phenyl azide, and electron-deficient C,C-Dipolarophiles
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In order to trap 'thiocarbonyl-aminides' A, formed as intermediates in the reaction of thiocarbonyl compounds with phenyl azide, a mixture of 2,2,4,4-tetramethyl-3-thioxocyclobutanone (1), phenyl azide, and fumarodinitrile (8) was heated to 80° until evolution of N2 ceased. Two interception products of the 'thiocarbonylaminide' A (Ar = Ph) were formed: the known 1,4,2-dithiazolidine 3 (cf. Scheme 1) and the new 1,2-thiazolidine 12 (Scheme 2). The structure of the latter was established by X-ray crystallography (Fig. 1). The analogous 'three-component reaction' with dimethyl fumarate (9) yielded, instead of 8, in addition to the known interception products 3 and 6 (Scheme 1), two unexpected products 15 and 16 (Scheme 3), of which the structures were elucidated by X-ray crystallography (Fig. 2). Their formation is rationalized by a primary [2 + 3] cycloaddition of diazo compound 18 with 1 to give 19, followed by a cascade of further reactions (Scheme 4).
- Mlostoń, Grzegorz,Romański, Jaroslaw,Linden, Anthony,Heimgartner, Heinz
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p. 1305 - 1314
(2007/10/03)
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- SITE SELECTIVITY IN THE REACTIONS OF 1,3-DIPOLES WITH NORBORNADIENE DERIVATIVES
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The cycloadditions of arylazides, benzonitrile oxides and diphenylnitrile imine to norbornadiene derivatives 1a-c showed varying degree of site- and stereo-selectivity.With dipolarophile 1a arylazides and benzonitrile oxides attack, preferentially, the electron-poor tetrasubstituted double bond, while in the case of 1b and 1c is the substituted double bond which enters the cycloaddition.By contrast, 2-diazopropane and C-phenyl-N-methylnitrone react with the sole tetrasubstituted double bond of 1a-c in stereo- and site-specific cycloadditions.The quantitative evaluation of the two possible reaction paths was performed by glc analysis.The compounds detected were those arising from Diels-Alder cycloreversions of the thermally labile intermediate adducts 2 and 3 (Scheme 1).The results were rationalized on the basis of a qualitative perturbation treatment which considers frontier orbital interactions only.
- Cristina, D.,Amici, M. De,Micheli, C. De,Gandolfi, R.
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p. 1349 - 1357
(2007/10/02)
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