Direct Excitation Strategy for Deacylative Couplings of Ketones.

Autor: Li J; School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 2001 Longxiang Road, Longgang District, Shenzhen, Guangdong, 518172, China., Zhang D; School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 2001 Longxiang Road, Longgang District, Shenzhen, Guangdong, 518172, China., Tan L; Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montréal, Québec, H3 A 0B8, Canada., Li CJ; Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montréal, Québec, H3 A 0B8, Canada.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2024 Oct 14; Vol. 63 (42), pp. e202410363. Date of Electronic Publication: 2024 Sep 12.
DOI: 10.1002/anie.202410363
Abstrakt: The homolysis of chemical bonds represents one of the most fundamental reactivities of excited molecules. Historically, it has been exploited to generate radicals under ultraviolet (UV) light irradiation. However, unlike most contemporary radical-generating mechanisms, the direct excitation to homolyze chemical bonds and produce aliphatic carbon-centered radicals under visible light remains rare, especially in metallaphotoredox cross couplings. Herein, we present our design of the dihydropyrimidoquinolinone (DHPQ) reagents derived from ketones, which can undergo formal deacylation and homolytic C-C bond cleavage to release alkyl radicals without external photocatalysts. Spectroscopic and computational analysis reveal unique optical and structural features of DHPQs, rationalizing their faster kinetics in alkyl radical generation than a structurally similar but visible-light transparent radical precursor. Such a capability allows DHPQ to facilitate a wide range of Ni-metallaphotoredox cross couplings with aryl, alkynyl and acyl halides. Other catalytic and non-catalyzed alkylative transformations of DHPQs are also feasible with various radical acceptors. We believe this work would be of broad interest, aiding the synthetic planning with simplified operation and expanding the synthetic reach of photocatalyst-free approaches in cutting-edge research.
(© 2024 Wiley-VCH GmbH.)
Databáze: MEDLINE
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