Cleavage of the C=N bond in carbodiimides via release of high ring strain: a new strategy for the selective synthesis of 2-aminoaryl alkynyl imines.
A novel pattern of the cleavage and reorganization of C=N bond in the multicomponent reaction (MCR) of terminal alkynes or haloalkynes, carbodiimides, and benzynes is achieved for the first time to construct efficiently 2-aminoaryl alkynyl imines. The selective formation and ring-opening of the azetine intermediate with the high ring strain is essential for this reaction. Further transformation of 2-aminoaryl alkynyl imines via the Cu-catalyzed cycloisomerization is explored to provide steroselectively the bi-, tri-, and tetracyclic fused pyrrolines.
Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871 (P.R. China), Fax: (+86) 10-62751708.
Yi
Y
Zhou
Yue
Y
Chi
Fei
F
Zhao
Wen-Xiong
WX
Zhang
Zhenfeng
Z
Xi
CN activation; alkynes; benzynes; carbodiimides; multicomponent reactions