Chlorinated compounds are found in various natural products such as Atpenin A5 (1), Perforenone B (2) or Clionastatin B (3), active pharmaceutical ingredients such as Quinfamide (4) or Chloramphenicol (5), and essential intermediates used in chemical manufacturing (Scheme 1A). Chlorine-based chemistry has been used in the synthesis of around 20% of small molecule drugs and 30% of agrochemical products. Among organochlorides, chloroalkanes serve as important synthetic precursors to access several functional groups, including alcohols, amines and thioethers. The classical methods for synthesizing chloroalkanes involve electrophilic addition of formal [Cl + ] intermediates to an olefin (Scheme 1B, eq. 1), nucleophilic substitution with chlorides [Cl -] (Scheme 1B, eq. 2), and the use of chlorine radicals [Cl•] (Scheme 1B, eq. 3). As they are difficult to control, chlorine radicals have long been considered of lower interest for fine chemical synthesis. Recently, based on important progress in radical chemistry, there has been a renewed focus on this approach. Different transformations have been developed, including radical additions to olefins, hydrogen atom transfer processes onto Csp 3 -H bonds, or oxidative cleavage of C-C  bonds. With an emphasis on sustainable chemistry in the past few decades, several photocatalytic protocols have been developed to convert electrophilic or nucleophilic chlorine sources to chlorine radicals. These methods include reductive activation, oxidative activation, and, more recently, ligand-to-metal charge transfer (LMCT) processes for the homolytic cleavage of metal chlorides. Hypervalent iodine reagents (HIRs) have similar properties as heavy metals in organic transformations. In particular, the homolytic fission of the I-Cl bond can generate chlorine radicals in analogy to LMCT processes (Scheme 1B, eq 4). Indeed, the photolysis of HIRs to give chlorine radicals has been described using iodine trichloride ICl3, Willgerodt reagent (6a) and recently chlorinated cyclic HIRs. Among them, 6a stands out as it is more stable and easier to handle than ICl3 and also more atom-economical than cyclic HIRs. 6a has been extensively applied for the electrophilic chlorination of Csp 2 centers such as olefins or aromatic rings (Scheme 1C, eq. 5), as well as for the oxidation of alcohols and thioethers. These pathways are potentially competitive with radical chlorination, suggesting that 6a would not be a good choice to favor this pathway. We hypothesized, however, that irradiation of 6a would lead to rapid homolytic fission of the I-Cl bond, producing chlorine radicals fast enough to suppress electrophilic chlorination pathways. As a result, highly selective radical chlorination of C-H and C-C bonds to form Csp 3 -Cl bonds could be achievable even in the presence of arenes or alcohols (Scheme 1C, eq. 6). Although the use of 6a for chlorination under photochemical conditions was initially introduced by Banks, it has been applied only to the chlorination of steroids by Breslow, Wicha, and co-workers in the 70's and 80's, and the potential of this approach in other chlorination reactions has not been further explored since then. Given that reagent 6a can be easily accessed via the reaction of chloride anions with iodosobenzene, it can potentially be generated in situ using a catalytic amount of iodobenzene in the presence of an external oxidant. Gilmour and Wirth recently reported catalytic iodine(I/III) chlorinations from CsCl or TMSCl, focusing on the electrophilic chlorination of olefins. A radical approach would allow to target not only olefins but also cyclopropanes C-C and alkanes C-H bonds.