Iron Catalysis of C(sp3)-H Azidation Using a Heteroarene Radical Cation Strategy

A Young Ji; Annaram Thirupathi; Joon Young Hwang; Yuri Kim; Gyuri Han; Kwang-Hyun Ahn; Kyungtae Kang; Eun Joo Kang

doi:10.1021/acs.orglett.3c00330

Iron Catalysis of C(sp³)-H Azidation Using a Heteroarene Radical Cation Strategy

Org Lett. 2023 Mar 10;25(9):1541-1546. doi: 10.1021/acs.orglett.3c00330. Epub 2023 Mar 1.

Authors

A Young Ji¹, Annaram Thirupathi¹, Joon Young Hwang¹, Yuri Kim¹, Gyuri Han¹, Kwang-Hyun Ahn¹, Kyungtae Kang¹, Eun Joo Kang¹

Affiliation

¹ Department of Applied Chemistry, Kyung Hee University, Yongin 17104, Korea.

PMID: 36856660
DOI: 10.1021/acs.orglett.3c00330

Abstract

The Fe^III(phen)₃ catalysis of the benzylic C(sp³)-H azidation of indoles has been investigated. The Fe(III) complex can selectively oxidize indoles to form arene radical cations, which are transformed into benzylic C(sp³) radical intermediates. This strategy exhibits a difference in reactivity between N-heteroarenes and benzene, which is difficult to achieve via direct hydrogen abstraction approaches. Various biorelevant azide precursors were constructed, highlighting the utility of this mild first-row transition-metal catalyst system.