In summary, we have developed a highly efficient method for the βchloroacylation of olefins from robust and readily available olefin and aroyl chloride feedstock with exceptional scope. This modular approach leverages a heteroleptic Cu(I)-photocatalyst to control acyl radical generation and C-Cl bond formation, enabling a redox-neutral process for olefin difunctionalization. It demonstrates remarkable compatibility with diverse functional groups and encompasses a broad substrate scope, thereby empowering the synthesis of valuable β-chloroketones across various chemical contexts, advocating this method to practical application in chemistry, pharmaceutical science, and materials science. Notably, our design features the introduction of an E-selective β-chloroacylation of phenylacetylene derivatives in a catalytic manifold highlighting the efficient regio-and stereo control of this ATRA process for aromatic alkynes. The effectiveness of this protocol in late-stage contexts is demonstrated, allowing the rapid generation of molecular complexity from large and densely functionalized olefins derived from biomolecules and pharmaceuticals. The synthetic utility of this method is demonstrated via the construction of various heterocycle and carbocycle scaffolds and the preparation of molecules widely used as building blocks for the synthesis of different natural products. Furthermore, this method paves the way towards the formal synthesis of pharmaceutically relevant haloperidol and seratrodast and naturally occurring piperidine alkaloid (-)-sedamine, which was not foreseeable previously due to the limitation of the title reaction towards unactivated alkenes. Multifaceted mechanistic studies have revealed that excited-state lifetime and ligand environment play a pivotal role in the success of this process, enabling highly efficient and expeditious rebound of Cu(II) following aroyl radical addition to olefins that can even outcompete a favorable intramolecular radical cyclization process.