Energy-transfer photocatalysis for Minisci C–H (amino)alkylation of heteroarenes using oxime esters as dual-role reagents

Abstract

Utilization of oxime esters as bifunctional reagents in energy-transfer photocatalysis has received considerable attention. However, the reaction type is so far limited to the difunctionalization of alkenes. To confront this limitation and enrich Minisci-type chemistry, herein we have developed a green and practical protocol for Minisci C–H (amino)alkylation of heteroarenes employing diverse oxime esters (from carboxylic acids) as (amino)alkylating reagents. The key to success of this Minisci reaction is that oxime esters play a dual role of (amino)alkylating reagents and oxidants. In addition, the useful approach not only tolerates a wide range of heteroarenes but also features a broad compatibility with different alkyl radicals, including primary-, secondary-, and tertiary-carbon species. Moreover, the practicability of this method is additionally boosted by the functionalization of various amino acids and approved carboxyl-containing drugs. This methodology not only provides a practical strategy for direct decarboxylative C–H (amino)alkylation of heteroarenes, but also broadens the reaction types for the mechanism involving photocatalyzed energy transfer.