769971-91-7Relevant academic research and scientific papers
Few unexpected results from a Suzuki-Miyaura reaction
Salanouve, Elise,Retailleau, Pascal,Janin, Yves L.
, p. 2135 - 2140 (2012)
In the course of the synthesis of original anti-infectious compounds we focused on the palladium-catalyzed Suzuki-Miyaura aryl-aryl coupling reaction between 2-(3-ethoxy-5-iodo-1H-pyrazol-1-yl)pyridine and phenylboronic acid. A study of the reaction products obtained under different conditions (various ligands and solvents), not only provided us with insights to optimize this reaction but also with few side compounds, resulting from CH activation, along with the unexpected bis(3-ethoxy-1-(pyridin-2-yl)-1H-pyrazol-5-yl)palladium. Stochiometric experiments with this remarkably stable biscyclopalladated reagent and phenylhalides pointed out the occurrence of aryl-aryl coupling, possibly via palladium IV intermediates.
3-Methoxypyrazoles from 1,1-dimethoxyethene, few original results
Salanouve, Elise,Guillou, Sandrine,Bizouarne, Marine,Bonhomme, Frédéric J.,Janin, Yves L.
experimental part, p. 3165 - 3171 (2012/06/01)
From the condensation between 1,1-dimethoxyethene and anhydrides, synthetically useful β,β-dimethoxy-α,β-unsaturated ketones were prepared. Upon addition of hydrazine, followed by iodination, 4-iodinated 3-methoxypyrazoles were obtained. The occurrence of a side compound also provided insights in the scope of this synthesis. In a second part, 1-(4-chlorophenyl)-3,3-dimethoxyprop-2-en-1-one was obtained from 1,1-dimethoxyethene and 4-chlorobenzoylchloride. The subsequent addition of hydrazine or phenylhydrazine led to 5-(4-chlorophenyl)-3-methoxy-1H-pyrazole or 1-phenyl-5-(4-chlorophenyl)-3-methoxypyrazole in unprecedented 64 or 54% overall yield. Unexpectedly, addition of 2-pyridylhydrazine led to the 2-([1,2,4]triazolo[4,3-a]pyridin-3-yl)-1-(4-chlorophenyl) ethanone. This led us to design original conditions, which led to the target 1-(2-pyridyl)-5-(4- chlorophenyl)-3-methoxypyrazole in a 39% overall yield. Additional examples are provided, starting from various carboxychlorides.
