A concise synthetic route to spiroindoline-fused S-heterocycles was developed through copper-catalyzed [4 + 1] annulation using enaminothiones as donor–acceptor synthons. Both 3-diazoindolin-2-imines and 3-diazooxindoles were amenable to work as effective C1 building blocks. The reaction proceeds via a copper-catalyzed cascade process involving the in situ generation of copper(I) carbene and C–S/C–C