Regioselective Chlorination of Aryl C−H bonds with Hypervalent Iodine(III) Reagent 1‐Chloro‐1,2‐benziodoxol‐3‐one

Abstract

We describe a copper(I) catalyzed ortho‐chlorination of aromatic compounds via direct C−H activation by using hypervalent iodine reagent 1‐chloro‐1,2‐benziodoxol‐3‐one. This reaction showed high regioselectivity for the monochlorination of the C−H bonds of 2‐phenyl pyridines and was compatible for a wide range of nitrogen‐containing aromatics. Furthermore, the synthesized iodine(III) reagent was highly stable, recyclable, and can be employed in large‐scale syntheses of halo‐heteroarenes.

Copper-Catalyzed/Hypervalent Iodine-Mediated Functionalization of Unactivated Compounds

“…However-although halogenated compounds widely studied and synthesized with copper catalysts [170][171][172]-the use of iodine in combination with copper catalysts is rather limited. In the field of C-Cl bond formation, Perumgani described a direct copper(I)-medi chlorination protocol of nitrogen-containing aromatic compounds using the chloro-io analogue of the Togni II reagent (Scheme 123) [174]. In this process the copper(I) cat promoted the homo-cleavage of the Cl-I bond in 88.…”

Recyclable Hypervalent Iodine Reagents in Modern Organic Synthesis

“…In 2017, Parvathaneni and Perumgani performed the highly regioselective copper-catalyzed chlorination of aromatic compounds 169 and 171 using 1-chloro-1,2-benziodoxol-3-one (96) and K 2 S 2 O 8 as additives in dichloromethane at 100 °C (Scheme 32). 85 The recycling of reagent 96 involves the recovery of its reduced form by simple solidliquid-phase separation followed by re-oxidation. 67 Scheme 32 Chlorination of various aromatic substrates 169 and 171 using 96…”

Cyclic Haloiodanes: Syntheses, Applications and Fundamental Studies

“…Parvathaneni and Perumgani used a copper catalyst to extend the scope of ortho ‐chlorination ( Scheme 50). [70] In this reaction, the nitrogen acts as directing group for the copper catalyst. The chlorinated aromatic ring is thus generally not the heteroaromatic ring, but the adjacent phenyl group ( Scheme 50 ,a–50,d ).…”