Metal-Free Annulation Cascades of 1,7-Enynes Using Di- tert-butyl Peroxide as the Methyl Source towards the Synthesis of Polyheterocyclic Scaffolds.

A new metal-free oxidative cascade methylation/cyclization of benzene-linked 1,7-enynes to construct methylated polyheterocyclic scaffold skeletons is described. In this transformation, three new C-C bonds and two new rings are formed. Notably, di- tert-butyl peroxide (DTBP) acts not only as a radical initiator but also as an efficient methyl source. [ABSTRACT FROM AUTHOR]