Year: 2025
Type: preprint
Abstract: Multi-step synthetic methods requiring harsh conditions and poor atom economy are central to the generation of aryne precursors. While the Kobayashi method is the gold standard for aryne generation under mild conditions, newer methods have relied on similar strategies of prefunctionalization. Here, we show the generation of arynes directly from commercially available hetero- and aryl halides via photothermal conversion under red-light irradiation and ambient atmosphere. Using photothermal conversion, we overcome the need for substrate prefunctionalization and generate the high energy aryne intermediate using inhomogeneous thermal gradients. We show that the aryne intermediate can be easily trapped by nitrogen nucleophiles to forge C–N bonds, important for pharmaceutical and agrochemical synthesis. A wide range of readily available nitrogen heterocycles and aryl halides undergo amination in less than 20 minutes under red light irradiation of carbon black. The product regioselectivity matches the expected distribution from aryne trapping, further supporting an aryne mechanism. Additionally, we show cycloaddition and trapping with sulfur and oxygen nucleophiles. This simplified method eliminates the need to use metal catalysts, multistep synthesis, and inert conditions for accessing a wide range of amination reactions.
Source: ChemRxiv
Institution: Princeton University
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7125498123