52482-62-9Relevant academic research and scientific papers
Late-Stage C-H Alkylation of Heterocycles and 1,4-Quinones via Oxidative Homolysis of 1,4-Dihydropyridines
Gutiérrez-Bonet, álvaro,Remeur, Camille,Matsui, Jennifer K.,Molander, Gary A.
supporting information, p. 12251 - 12258 (2017/09/12)
Under oxidative conditions, 1,4-dihydropyridines (DHPs) undergo a homolytic cleavage, forming exclusively a Csp3-centered radical that can engage in the C-H alkylation of heterocyclic bases and 1,4-quinones. DHPs are readily prepared from aldehydes, and considering that aldehydes normally require harsh reaction conditions to take part in such transformations, with mixtures of alkylated and acylated products often being obtained, this net decarbonylative alkylation approach becomes particularly useful. The present method takes place under mild reaction conditions and requires only persulfate as a stoichiometric oxidant, making the procedure suitable for the late-stage C-H alkylation of complex molecules. Notably, structurally complex pharmaceutical agents could be functionalized or prepared with this protocol, such as the antimalarial Atovaquone and antitheilerial Parvaquone, thus evidencing its applicability. Mechanistic studies revealed a likely radical chain process via the formation of a dearomatized intermediate, providing a deeper understanding of the factors governing the reactivity of these radical forebears.
Dioxygen-Mediated Decarbonylative C-H Alkylation of Heteroaromatic Bases with Aldehydes
Paul, Subhasis,Guin, Joyram
supporting information, p. 17618 - 17622 (2015/12/05)
An operationally simple and economical method for the direct alkylation of heteroaromatic bases employing readily available aldehydes as alkyl radical precursors and molecular oxygen as a reagent is presented. This simple transformation demonstrates a broad substrate scope with respect to aldehydes and nitrogen heterocycles, enabling the introduction of several medicinally important yet challenging alkyl moieties, such as ethyl, isopropyl, tert-butyl, and cyclohexyl to the different classes of heterocyclic bases in good to excellent yields. A simple method for the direct alkylation of heteroaromatic bases with aldehydes as inexpensive alkyl radical precursors and molecular oxygen as a reagent is presented. This transformation demonstrates a broad substrate scope with respect to aldehydes and nitrogen heterocycles, enabling the introduction of various alkyl moieties to heterocyclic bases (>40 examples) in good to excellent yields.
Photochemical Reactions of Caffeine with Aliphatic Aldehydes
Erndt, Aleksander,Fiedorowicz, Maciej,Kostuch, Andrzej,Para, Andrzej
, p. 1043 - 1046 (2007/10/02)
Photochemical reactions of caffeine with several aliphatic aldehydes are performed.In the reactions with ethanal, propanal and butanal stable 8-acyl-8,9-dihydrocaffeines 2 and 3 together with unreduced 8-acylcaffeines 4 and 8-(α-hydroxy-alkyl)caffeines 6 are produced.Under similar conditions, the reactions of 2-methylpropanal, 2-methylbutanal and 2,2-dimethylbutanal resulted in the formation of the corresponding 8-alkylcaffeines 7. - Key Words: Caffeine / Aldehydes / Photochemistry / Purines
