Base-Mediated Cascade Lactonization/1,3-Dipolar Cycloaddition Pathway for the One-Pot Assembly of Coumarin-Functionalized Pyrrolo[2,1-<i>a</i>]isoquinolines
Qiang Tang, Yanan Liu, Binbin Fei, Qianqian Tao, Chen Wang, Xiaochun Jiang, Xinwei He, Yongjia Shang
Abstract
An elegant and highly concise strategy for the construction of coumarin-functionalized pyrrolo[2,1- a ]isoquinolines from available propargylamines and isoquinolinium N -ylides has been disclosed. In this reaction, isoquinolinium N -ylides acted as a C2 synthon to form a coumarin ring as well as a 1,3-dipole to construct a pyrrole ring in a single pot. This cascade process involves 1,4-conjugate addition/lactonization/1,3-dipolar cycloaddition to construct four chemical bonds (one C–O bond and three C–C bonds) and two new heterocyclic skeletons. Additionally, most of these compounds showed good fluorescence properties and exhibited high molar extinction coefficient and large Stokes shifts.