854461-65-7Relevant academic research and scientific papers
Intermolecular Photoredox Coupling: Alternative to Norrish Type II Reaction and Yang Cyclization in Ketones with γ-C?H Bonds
Hoffmann, Heiko,Tausch, Michael W.
supporting information, p. 3665 - 3669 (2021/06/16)
A new reaction pathway for the photoconversion of butyrophenone in acetonitrile was investigated. In addition to the classic intramolecular photoreactivity of ketones with γ-C?H bonds (Norrish type II fragmentation and Yang cyclization), intermolecular generated species were isolated and characterized: 1,2-Dibenzoylethane, 2-phenacylacetonitrile (oxidized species) and pinacols (reduced species). They account for approx. 20 % of the converted starting material, similar to the Yang product. The acetophenone enol intermediate, formed in situ via the Norrish type II reaction, has been identified as an H-atom donor for the main intermolecular reaction steps, and has been distinguished from other conceivable mechanistic possibilities. Experimental results with analogue compounds suggest that the intermolecular product formation pathway may be of general relevance.
Oxazolium Salts as Organocatalysts for the Umpolung of Aldehydes
Garapati, Venkata Krishna Rao,Gravel, Michel
supporting information, p. 6372 - 6375 (2018/10/15)
Oxazolium salts were successfully employed for the first time as organocatalysts for benzoin, Stetter, and redox esterification reactions. An N-mesityl oxazolium salt catalyzed homobenzoin reaction of aromatic, heteroaromatic, and aliphatic aldehydes delivered α-hydroxy ketones in high yields. This new type of catalyst proved remarkably effective for the Stetter reaction of challenging substrates such as β-alkyl-α,β-unsaturated ketones and electron-rich aromatic aldehydes in comparison to common thiazolium and triazolium salts.
