- Synthesis of α-Chlorolactams by Cyanoborohydride-Mediated Radical Cyclization of Trichloroacetamides
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A cyanoborohydride-promoted radical cyclization methodology has been developed to access α-chlorolactams in a simple and efficient way using NaBH3CN and trichloroacetamides easily available from allylic and homoallylic secondary amines. This methodology allowed the synthesis of a library of α-chlorolactams (mono- and bicyclic), which were tested for herbicidal activity, trans-3-chloro-4-methyl-1-(3-trifluoromethyl)phenyl-2-pyrrolidinone being the most active.
- Coussanes, Guilhem,Jakobi, Harald,Lindell, Stephen,Bonjoch, Josep
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supporting information
p. 8151 - 8156
(2018/05/30)
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- A green way to γ-lactams through a copper catalyzed ARGET-ATRC in ethanol and in the presence of ascorbic acid
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A 'green' ARGET-ATRC, for the CuCl[PMDETA] catalysed cyclo-isomerization of N-allyl-α-polychloroamides to γ-lactams is described. The process works efficiently (yields 78-96%), uses a bio-solvent, as ethanol, and exploits the reducing feature of ascorbic acid to limit, at a low level (2-4%), the amount of catalyst. To preserve the efficacy of the catalytic cycle, addition of Na2CO3 is essential, which quenches the HCl released during the CuCl[PMDETA] regeneration step. Profitable features of the process are: mild reaction temperatures (25-37 °C), relatively short reaction times (usually 5 h) and low solvent volumes (2 mmol of substrate/mL of ethanol). The method, upon stoichiometric adjustment, was also used for the synthesis of α,β-unsaturated-γ-lactams from N-(2-chloroallyl)-α- polychloroamides, via a tandem process involving an ATRC and a reductive [1,2]-elimination. Copyright
- Casolari, Roberto,Felluga, Fulvia,Frenna, Vincenzo,Ghelfi, Franco,Pagnoni, Ugo M.,Parsons, Andrew F.,Spinelli, Domenico
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experimental part
p. 408 - 416
(2011/03/18)
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- Radical reactions using decacarbonyldimanganese under biphasic conditions
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Radical reactions of alkyl halides, initiated by photolysis in the presence of decacarbonyldimanganese, can be performed in biphasic media. Reactions in the presence of aqueous sodium hydroxide together with a phase-transfer catalyst result in the efficient removal of manganese halide by-products and also lead to the regeneration of decacarbonyldimanganese. A range of efficient radical couplings, cyclisations and intermolecular addition reactions were performed under these conditions. This included the development of a new tandem radical addition-ionic cyclisation sequence that was employed in a short approach to (±)-coronamic acid. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Huther, Nathalie,McGrail, P. Terry,Parsons, Andrew F.
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p. 1740 - 1749
(2007/10/03)
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- New synthesis of heterocycles by use of palladium catalyzed cycli zation of α-haloamide with internal double bond
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α-Haloamide having internal double bond was allowed to react with a catalytic amount of Pd(PPh3)4 in the presence of base to produce a cyclized product in a fairly good yield possibly through the intermediate of -alkylmetal complex. By use of this method, five and six membered lactams, pyrrolizidine and quinolizidine derivatives were synthesized in fairly good yields.
- Mori, Miwako,Kanda, Nana,Oda, Izumi,Ban, Yoshio
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p. 5465 - 5474
(2007/10/02)
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