18.4: Alkylation of Aldehydes and Ketones - Chemistry LibreTexts
Overall an α hydrogen is replaced with an alkyl group. This reaction is one of the more important for enolates because a carbon-carbon bond is formed. These alkylations are affected by the same limitations as S N 2 reactions previously discussed. A good leaving group, Chloride, Bromide, Iodide, Tosylate, should be used.
Asymmetric α-Alkylation of Aldehydes, Ketones, and Carboxylic …
2013年9月24日 · The α-alkylation of aldehydes and ketones is fundamental to synthetic organic chemistry. Although electrophilic addition to derived enolates is a viable means of achieving this transformation in the case of ketones, it is not particularly useful for simple aldehyde substrates.
Direct β-Alkylation of Aldehydes via Photoredox Organocatalysis
2014年4月22日 · Direct β-alkylation of saturated aldehydes has been accomplished by synergistically combining photoredox catalysis and organocatalysis. Photon-induced enamine oxidation provides an activated β-enam...
2017年6月26日 · Here, we show that the synergistic merger of three catalytic processes—photoredox, enamine and hydrogen-atom transfer (HAT) catalysis enables an enantioselective -aldehyde alkylation reaction that employs simple olefins as coupling α partners.
Merging Photoredox Catalysis with Organocatalysis: The Direct ...
2008年10月3日 · Specifically, the enantioselective intermolecular α-alkylation of aldehydes has been accomplished using an interwoven activation pathway that combines both the photoredox catalyst Ru (bpy) 3 Cl 2 (where bpy is 2,2′-bipyridine) and an imidazolidinone organocatalyst.
Direct, enantioselective α-alkylation of aldehydes using simple …
Here, we show that the synergistic merger of three catalytic processes—photoredox, enamine and hydrogen-atom transfer (HAT) catalysis—enables an enantioselective α-aldehyde alkylation reaction that employs simple olefins as coupling partners.
Radical-Mediated α- tert -Alkylation of Aldehydes by …
2024年5月28日 · In this study, we present a novel radical-mediated tert -alkylation approach targeting the α-position of aldehydes, enabling the synthesis of complex aliphatic aldehydes.
Direct, enantioselective α-alkylation of aldehydes using ... - Nature
2017年6月26日 · Here, we show that the synergistic merger of three catalytic processes—photoredox, enamine and hydrogen-atom transfer (HAT) catalysis—enables an enantioselective α-aldehyde alkylation reaction...
In what follows, a brief overview of the current state-of-the-art approaches to asymmetric a-alkylation of carbonyl compounds is presented.
Mechanism of the Stereoselective α-Alkylation of Aldehydes …
2016年6月6日 · In summary, we have used a combination of conventional photophysical investigations, NMR spectroscopy, and kinetic studies to elucidate the key mechanistic aspects of the enantioselective photochemical α-alkylation of aldehydes with electron-poor organic halides.