Cascade Reactions Initiated by Addition of C-Centered Radicals to Alkynes

1 Cascade Reactions Initiated by Addition of C-Centered Radicals to Alkynes 

Azobisisobutyronitrile (AIBN) is a widely used radical initiator that usually does not get involved as a reagent in radical reactions itself. Montevecchi et al. reported 

5-exo cyclization to the alkyne moiety, followed by 6-endo cyclization of vinyl radical 51. If, instead of iodoalkynes of type 47, iodonitriles are used as precursors of C radicals, pyrazines are obtained in an analog cyclization cascade (not shown). 

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