Copper-catalyzed oxidative [2+2+1] annulation of 1,n-enynes with α-carbonyl alkyl bromides through C–Br/C–H functionalization

Abstract

The Cu-catalyzed oxidative [2+2+1] annulation of 1,n-enynes (n = 6, 7) with α-carbonyl alkyl bromides through C–Br/C–H functionalization has been developed. Using Ag₂CO₃/tert-butyl hydroperoxide (TBHP) as co-oxidants, α-carbonyl alkyl bromides provide two bonds, the α-C(sp³)–Br bonds and the α-C(sp³)–H bonds, to cyclize with the 1,n-enynes and Cu(MeCN)₄PF₆, thus forming three new C–C bonds and two rings in a single reaction.