A base-promoted [3 + 2] cycloaddition for the construction of multi-functionalized imidazo[1,2-a]indole derivatives with good yields has been accomplished. This transformation provides an easy and facile protocol for the formation of diverse imidazo[1,2-a]indoles of chemical and biomedical importance using preformed 3-sulfonyl-2-sulfonyldiazenyl-1H-indoles and readily available but-2-ynedioates under mild conditions.
![Graphical abstract: Cs2CO3-promoted [3 + 2] cycloaddition providing an easy protocol toward imidazo[1,2-a]indole derivatives](http://hg.y866.cn/compound/lib/scimg/usr/1/C5RA13319J.jpg)
