The multi-faceted reactivity of alkyl chlorides makes them important building blocks for the assembly of architecturally complex C(sp 3 )rich molecules (Figure ) 1 . Despite their well-recognized utilities, methods to access alkyl chlorides directly from readily available reagents remain rare 2 , beyond classical syntheses from Markovnikov additions to alkenes 3 and substitution reactions of alcohols . One area that has resulted in the evolution of new technologies for the synthesis of complex alkyl chlorides has been transformations based on the difunctionalization of alkenes. In the 1950s, Meerwein and co-workers developed a radical-based approach to alkyl chloride synthesis through the aryl-chlorination of alkenes (Figure ) . In this process, aryl radical additions to an alkene result in a homobenzylic radical that either directly engages a chloride ion via group transfer or is oxidized to a carbocation, which reacts with the halide anion. Although several modifications have been made by Doyle 6a, b , Nobile 7 , Grishchuck and others, Meerwein-type aryl-chlorination still exhibits limited compatibility with non-activated alkenes. This drawback is often attributed to the slow addition of aryl radicals to the low polarity carbon-carbon double bond in non-activated alkenes (10 6 ~ 10 7 M -1 s -1 vs 10 7 ~ 10 8 M -1 s -1 for α,β-unsaturated alkenes) and that the intermediacy of a carbocation inevitably causes chemoselectivity issues via competing elimination 10 . Palladium-catalyzed alkene aryl-chlorination methods have emerged as an effective means of synthesizing complex alkyl chlorides 11 . 1,2-Aryl-palladation to the carbon-carbon double bond of the alkene generates an alkyl-Pd(II) intermediate, the interception of which with a highly electrophilic chlorination reagent leads to the formation of a putative alkyl-Pd(IV)Cl species and prompts C-Cl bond formation through reductive elimination. Although these high-valent Pd-mediated transformations have underpinned the syntheses of many β-arylethyl chlorides, the use aryl tin reagents diminishes the attractiveness of these methods (Figure ) . We reasoned that the invention of a mechanistically distinct modular and catalytic method for the synthesis of alkyl chlorides would be a valuable addition to the arsenal of synthetic tools and of interest to practitioners of molecule-making in academic and industrial environments. Recently, we described the development of a dual catalytic platform for the aryl functionalization of alkenes based on a photocatalytic reduction of diaryliodonium salts, to generate an aryl radical that adds to an alkene, and a separate transition metal catalyzed group transfer cycle that orchestrates a reaction between the incipient homobenzylic radical and an anionic nucleophile. This platform resulted in new methods for the azido-arylation of alkenes and the chloro-arylation of vinyl boronic esters . A compelling aspect of this activation mode is the capacity to select from several different photocatalysts and group transfer catalysts, respectively, in response to the diverse needs of the reaction. For example, we found that two copper-based catalysts were optimal for azido-arylation , but a ruthenium photocatalyst in combination with an iron group transfer catalyst were preferable for the aryl chlorination of vinyl boronic esters . We questioned whether our dual catalysis strategy could be engineered to accommodate a range of electronically diverse alkenes towards a broadly applicable aryl-chlorination reaction, during which the formation of the carbon-chlorine bond proceeds exclusively through a catalyzed group transfer pathway rather than radical coupling or carbocation pathways, which define other processes . Balancing the requirements of both the photocatalytic and group transfer cycles, the low oxidation potential of the chloride and the reactivities of diverse alkyl radicals is challenging, with a productive reaction outcome may not always be possible with a single catalyst system. However, the flexibility of our dual catalysis platform means that both photocatalyst and group transfer catalyst can be readily exchanged and tailored to the different requirements of individual substrates, therefore making the identification of optimal processes more readily attainable.