The pharmaceutically important tetrahydroquinoline spiro compounds were efficiently constructed via cascade SNAr/Knoevenagel condensation/[1,5]-hydride transfer/cyclization on water, featuring high atom-economy and step-economy. This water-based redox-neutral C(sp3)–H functionalization rendered a 4-step cascade reaction successful without resorting to any catalysts.
![Graphical abstract: Construction of the tetrahydroquinoline spiro skeleton via cascade [1,5]-hydride transfer-involved C(sp3)–H functionalization “on water”](http://hg.y866.cn/compound/lib/scimg/usr/1/C7GC02353G.jpg)
