Domino reactions radical based

The occurrence of the indole subunit is well established within the class of natural products and pharmaceutically active compounds. Recently, the Reissig group developed an impressive procedure for the assembly of highly functionalized in-dolizidine derivatives, highlighting again the versatility of domino reactions [8]. The approach is based on a samarium(II) iodide-mediated radical cydization terminated by a subsequent alkylation which can be carried out in an intermolecular - as well as in an intramolecular - fashion. Reaction of ketone 3-11 with samarium(ll) iodide induced a 6-exo-trig cydization, furnishing a samarium enolate intermediate... 

Jahn et al. reported an elegant new domino process based on the combination of anionic and radical reactions relying on a key oxidation of anion 249 followed by a radical cyclization leading to 250 (Scheme 74) [207]. Radical 250 can be trapped by TEMPO to yield functionaUzed pyrrolidine 251 in high yield and acceptable stereoselectivity the 2-3 cis relationship was controlled in the initial anionic addition, but the relative configurations at C3 and C4 were largely non-controlled. All-carbon cyclopentanes [208], in particular prostanes [209] could also be prepared through this method. More recently, Jahn and Rudakov reported its extension to nitroalkenes [210]. 

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