Synthesis 2010(4): 694-700  
DOI: 10.1055/s-0029-1218583
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

‘Ligand-Free-Like’ CuCl-Catalyzed Atom Transfer Radical Cyclization of N-Substituted N-Allyl Polychloroamides to γ-Lactams

Mariella Pattarozzi*, Fabrizio Roncaglia, Valerio Giangiordano, Paolo Davoli, Fabio Prati, Franco Ghelfi*
Dipartimento di Chimica, Università degli Studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy
Fax: +39(059)373543; e-Mail: franco.ghelfi @unimore.it;
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Publikationsverlauf

Received 19 October 2009
Publikationsdatum:
27. November 2009 (online)

Abstract

Atom transfer radical cyclization (ATRC) of N-alkyl N-allyl dichloroamides to γ-lactams, catalyzed by ‘naked’ CuCl, worked efficiently in DMF, whereas, when the same dichloro­amides were N-sulfonylated, DMF needed to be replaced by acetonitrile. The outcome of the cycloisomerization with N-substituted N-allyl trichloroacetamides was less affected by solvent choice, although for an effective reaction to occur, the solvent had to dissolve the cuprous salt. Catalyst loading ranged between 5 and 20 mol%.