Ir(III)-Catalyzed Oxidative Coupling of NH Isoquinolones with Benzoquinone.
The oxidative coupling reactions of NH isoquinolones with 1,4-benzoquinone proceeded efficiently to form spiro compounds in the presence of an Ir(III) catalyst through C-H activation. The reactions have a broad range of substrates, with nearly quantitative yields, without the use of external oxidants. For 1,4-naphthoquinone and other substituted 1,4-benzoquinone substrates the reactions also gave high yields with Cu(OAc)2·H2O as an external oxidant. A catalytically competent five-membered iridacycle has been isolated and structurally characterized, thus revealing a key intermediate in the catalytic cycle.
Tao
T
Zhou
Liubo
L
Li
Bin
B
Li
Haibin
H
Song
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , Shanghai 200032, People's Republic of China.
Baiquan
B
Wang