Yannick Borguet - -     Tandem Catalysis of Ring-Closing Metathesis/ Atom Transfer Radical Reactions with Homobimetallic Ruthenium-Arene Complexes

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      Publication Details (including relevant citation   information):

      Yannick Borguet1, Xavier Sauvage1,   Guillermo Zaragoza2, Albert Demonceau1 and   Lionel Delaude1,Beilstein J. Org. Chem.   2010, 6, 1167-1173

      Abstract:

      The tandem catalysis of ring-closing metathesis/atom transfer   radical reactions was investigated with the homobimetallic   ruthenium–indenylidene complex   [(p-cymene)Ru(μ-Cl)3RuCl(3-phenyl-1-indenylidene)(PCy3)]   (1) to generate active species in situ. The two   catalytic processes were first carried out independently in a   case study before the whole sequence was optimized and applied to   the synthesis of several polyhalogenated bicyclic γ-lactams and   lactones from α,ω-diene substrates bearing trihaloacetamide or   trichloroacetate functionalities. The individual steps were   carefully monitored by 1H and 31P NMR   spectroscopies in order to understand the intimate details of the   catalytic cycles. Polyhalogenated substrates and the ethylene   released upon metathesis induced the clean transformation of   catalyst precursor 1 into the Ru(II)–Ru(III)   mixed-valence compound   [(p-cymene)Ru(μ-Cl)3RuCl2(PCy3)],   which was found to be an efficient promoter for atom transfer   radical reactions under the adopted experimental conditions.

      Address (URL): http://www.beilstein-journals.org/bjoc/single/articleFullText.htm?vt=f&publicId= 1860-5397-6-133&sn=12&bpn=singleSeries&dos=0