- Intermolecular aminocarbonylation of alkenes using concerted cycloadditions of iminoisocyanates
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The aminocarbonylation of alkenes is a powerful method for accessing the β-amino carbonyl motif that remains underdeveloped. Herein, the development of intermolecular aminocarbonylation reactivity of iminoisocyanates with alkenes is presented. This includes the discovery of a fluorenone-derived reagent, which was effective for many alkene classes and facilitated derivatization. Electron-rich substrates were most reactive, and this indicated that the LUMO of the iminoisocyanate is reacting with the HOMO of the alkene. Computational and experimental results support a concerted asynchronous [3 + 2] cycloaddition involving an iminoisocyanate, which was observed for the first time by FTIR under the reaction conditions. The products of this reaction are complex azomethine imines, which are precursors to valuable β-amino carbonyl compounds such as β-amino amides and esters, pyrazolones, and bicyclic pyrazolidinones. A kinetic resolution of the azomethine imines by enantioselective reduction (s = 13.43) allows access to enantioenriched products. Overall, this work provides a new tool to convert alkenes into β-amino carbonyl compounds.
- Bongers, Amanda,Clavette, Christian,Gan, Wei,Gorelsky, Serge I.,Betit, Lyanne,Lavergne, Kaitlyn,Markiewicz, Thomas,Moon, Patrick J.,Neves, Nicolas Das,Obhi, Nimrat K.,Toderian, Amy B.,Beauchemin, Andrei M.
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p. 1175 - 1194
(2017/11/14)
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- Lipase-catalyzed kinetic resolution of 2-aminocyclopentane- and 2-aminocyclohexanecarboxamides
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Candida antarctica lipase B (CAL-B)-catalyzed N-acylation with 2,2,2-trifluoroethyl butanoate in solvent mixtures of tert-butyl methyl ether and tert-amyl alcohol was used to prepare all the enantiomers of cis- and trans-2-aminocyclopentane- and -cyclohexanecarboxamides. An unexpected change in enantiopreference, accompanied by low enantioselectivity, was observed when Pseudomonas cepacia lipase (cis-cyclohexane substrate) or C. antarctica lipase A (cis-cyclopentane and -cyclohexane substrates) replaced CAL-B.
- Fitz, Monika,Lundell, Katri,Fueloep, Ferenc,Kanerva, Liisa T.
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p. 1129 - 1134
(2007/10/03)
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- Antiamyloid phenylsulfonamides: N-cycloalkylcarboxamides derivatives
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A series of N-cycloalkylcarboxamide derivatives of N-benzyl benzenesulfonamides of Formula I are described. The compounds inhibit β-amyloid peptide (β-AP) production and are useful in the treatment of Alzheimer's Disease and other conditions characterized
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Page/Page column 8
(2010/02/11)
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- A novel preparation of 2-aminocyclopentanecarboxamides
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Different syntheses of cis- and trans-2-aminocyclopentanecarboxamides were studied. A convenient and effective method was devised for the preparation of cis-2-aminocyclopentanecarboxamide derivatives starting from the readily available 6-tert-butoxycarbon
- Csomos, Peter,Bernath, Gabor,Fueloep, Ferenc
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p. 1077 - 1084
(2007/10/03)
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