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

The Cu-catalyzed oxidative [2+2+1] annulation of 1,n-enynes (n = 6, 7) with alpha-carbonyl alkyl bromides through C-Br/C-H functionalization has been developed. Using Ag2CO3/tert-butyl hydroperoxide (TBHP) as co-oxidants, alpha-carbonyl alkyl bromides provide two bonds, the alpha-C(sp(3))-Br bonds and the alpha-C(sp(3))-H bonds, to cyclize with the 1,n-enynes and Cu(MeCN)(4)PF6, thus forming three new C-C bonds and two rings in a single reaction.