O-Transfer-facilitated cyclizations of propargylamides with TMSN3: selective synthesis of tetrazoles and dihydroimidazoles.
An unprecedented formal [3+2] annulation of propargylamides with TMSN3 to deliver functionalized tetrazoles is developed. Oxygen-atom transfer (OAT) from the amide group to the C≡C bond was realized via a NIS-triggered-cyclization/ring-opening cascade pathway. The OAT process enables the amide to serve as a two-atom unit in the reactions. Notably, in situ umpolung of azide occurred when terminal propargylamides were employed in this reaction, providing an array of diiodomethylated dihydroimidazoles.
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China. bswan@dicp.ac.cn cxwang@dicp.ac.cn.
Yancheng
Y
Hu
Ruxia
R
Yi
Xinzhang
X
Yu
Xiaoyi
X
Xin
Chunxiang
C
Wang
Boshun
B
Wan