Work

Ir/Ni Metallaphotoredox Catalysis for the C(sp3)─H Bond α‐Arylation and Alkylation of N‐Alkyl N‐Heterocycles

Year: 2025

Type: article

Abstract: In this work, we report a regioselective C(sp3)─H bond α‐arylation and alkylation of N‐alkyl heterocycles (carbazoles, indoles and indazoles) using a Ir/Ni metallaphotoredox catalysis. This approach enables the direct functionalization of unactivated C(sp3)─H bonds at the α‐position of nitrogen heterocycles, offering an efficient alternative to traditional Sn2 methods and providing complementary regioselectivity to transition metal catalysis, which often results in C(sp2)─H bond arylation. The reaction employs [Ir(dF(CF3)ppy)2(dtbbpy)][PF6] as the photocatalyst and NiCl2(dtbbpy) as the nickel source, facilitating single‐electron transfer (SET) to promote radical generation and organometallic elementary cross‐coupling steps. The methodology allows the use of diverse aryl chlorides and alkenes demonstrating broad substrate scope and high functional group tolerance. Mechanistic investigations, including radical trapping and and Stern–Volmer experiments, support a photocatalytic radical pathway. This metallaphotoredox protocol presents a robust and atom‐economical route to synthesizing valuable N‐alkyl‐N‐aryl heterocycles.

Source: Chemistry - A European Journal

DOI: 10.1002/chem.202500938

Authors: Bin Lv, Fangying Ling, Jean‐François Soulé

Institutions: Centre National de la Recherche Scientifique, Chimie ParisTech - PSL, Université Paris Sciences et Lettres, Institute of Chemistry for Life and Health Sciences, ParisTech

Language: English

Topic: Radical Photochemical Reactions

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,640

Funder: China Scholarship Council