In Situ Generation of (Dichloroiodo)benzene From PhI(OAc) 2 and SOCl 2 : Application to the Synthesis of Chlorinated 1,3‐Dicarbonyl and Aromatic Compounds

(Dichloroiodo)benzene (PhICl 2 ) is a powerful reagent used in chlorination, but its practical utility is often limited by instability and hazardous methods of synthesis. We developed a straightforward and efficient protocol for in situ generation of PhICl 2 utilizing (diacetoxyiodo)benzene [PhI(OAc) 2 ] and thionyl chloride (SOCl 2 ). Mechanistic studies confirmed in situ generation of PhICl 2 from PhI(OAc) 2 and SOCl 2 . Highly selective α ‐mono‐chlorination of 1,3‐dicarbonyl compounds was achieved using the in situ‐generated PhICl 2 under mild conditions; α , α ′‐di‐chlorinated products were successfully obtained by adjusting the reagent stoichiometry. The chlorination of aromatic rings further demonstrated the versatility of this protocol.