Sulfur Incorporation Using Disulfanes as the Sulfur Atom Source Enabled Metal-Free Heteroannulation of 1,7-Enynes

Article abstract of DOI:10.1002/adsc.201900621

A new oxidative [2+2+1] heteroannulation of 1,7-enynes with disulfanes promoted by Et₃N, producing 3,3a-dihydro-thieno[3,4-c]quinolin-4(5H)-ones, is described. This reaction is achieved by using equivalent amounts of 1,7-enynes, sulfur atoms (disulfanes), tert-butyl peroxybenzoate (TBPB) as an oxidant and Et₃N as the base, and represents an unprecedented strategy to applications of disulfanes as sulfur atom sources in synthesis. (Figure presented.).