Year: 2025
Type: article
Abstract: ABSTRACT Ortho‐alkoxy trifluoroacetophenones undergo efficient cyclization to benzofuranols under UV light irradiation (370 nm). Key to success is a 1,6‐hydrogen atom transfer (1,6‐HAT), which is enabled by the unique properties of the trifluoroacetophenone unit and strategic positioning of the methoxy group. The reaction proceeds best under dilute conditions, in polar aprotic solvents, and with high‐intensity irradiation. Although triplet quenching and intermolecular HAT limit certain aromatic substitution patterns, the reaction still accommodates a diverse set of substrates, providing access to tertiary benzofuranols, including spirocyclic compounds (12 examples, up to 92% yield, up to 90:10 diastereomeric ratios [dr]). Subsequent dehydration provides trifluoromethyl‐substituted benzofurans, offering a convenient route to these heterocycles.
Source: Helvetica Chimica Acta
Authors: Abhilash Pedada, Johannes M. Wahl
Institution: Johannes Gutenberg University Mainz
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,030
OpenAlex ID: W4415934906