Aerobic, Metal-Free, and Catalytic Dehydrogenative Coupling of Heterocycles: En Route to Hedgehog Signaling Pathway Inhibitors
摘要:
The nitrosonium ion-catalyzed dehydrogenative coupling of heteroarenes under mild reaction conditions is reported. The developed method utilizes ambient molecular oxygen as a terminal oxidant, and only water is produced as byproduct. Dehydrogenative coupling of heteroarenes translated into the rapid discovery of novel hedgehog signaling pathway inhibitors, emphasizing the importance of the developed methodology.
Mechanistic Insights on Orthogonal Selectivity in Heterocycle Synthesis
作者:Arun Maji、Yernaidu Reddi、Raghavan B. Sunoj、Debabrata Maiti
DOI:10.1021/acscatal.8b02537
日期:2018.11.2
Recently, we have developed a method for catalytic regioselectivesynthesis of 2-substituted and 3-substituted benzofurans starting from phenols. The choice of reacting partner, olefin versus α,β-unsaturated acid, is critical to dictate the isomeric product formation. Instances are known where these olefinic partners did not complement each other and yield a similar outcome. In the current work, we
yields under the standard conditions. An efficient palladium-catalyzed addition of arylboronic acids to aliphatic nitriles has been developed, providing a wide range of alkylarylketones in moderate to excellent yields. It is noteworthy that sequential addition and intramolecular annulation reaction of 2-(2-hydroxyphenyl)acetonitriles with arylboronic acids are also conducted smoothly to afford 2-arylbenzofurans
Regiocontroled Palladium-Catalysed Direct Arylation at Carbon C2 of Benzofurans using Benzenesulfonyl Chlorides as the Coupling Partners
作者:Lenka Loukotova、Kedong Yuan、Henri Doucet
DOI:10.1002/cctc.201301077
日期:2014.3.10
products together with C2,C3 diarylation products. We found that the use of benzenesulfonylchlorides instead of aryl halides as the coupling partner allows for controlling the regioselectivity of the palladium‐catalysed arylation of benzofurans in favour of carbon C2. This method tolerates a variety of substituents on the benzenesulfonyl derivative.
Microwave-assisted efficient synthesis of 2-arylbenzo[b]furans and 2-ferrocenylbenzo[b]furans from readily prepared propargylic alcohols and o-iodophenols
one-pot with iodobenzene, 2-methyl-3-butyn-2-ol and 2-iodo-4-methylphenol as reactants. A simple and efficient method for synthesis of 2-arylbenzo[b]furnas and 2-ferrocenylbenzo[b]furans has been developed from the Sonogashira coupling/cyclization reaction of propargylic alcohols and o-iodophenols in the presence of silica gel and catalytic amounts of PdCl2(PPh3)2 (2 mol%) and CuI (2 mol%) under microwave
Palladium-Catalyzed Addition of Potassium Aryltrifluoroborates to Aliphatic Nitriles: Synthesis of Alkyl Aryl Ketones, Diketone Compounds, and 2-Arylbenzo[<i>b</i>]furans
developed, leading to a wide range of alkylarylketones with moderate to excellent yields. Moreover, several dinitriles (e.g., malononitrile, glutaronitrile, and adiponitrile) were applicable to this process for the construction of 1,3-, 1,5-, or 1,6-dicarbonyl compounds. The scope of the developed approach is successfully explored toward the one-step synthesis of 2-arylbenzo[b]furans via sequential
已经开发了钯催化的芳基三氟硼酸钾加成到脂肪族腈中的方法,从而产生了范围广泛的烷基芳基酮,并具有中等至极好的收率。此外,几种二腈(例如丙二腈,戊二腈和己二腈)适用于该方法,用于构建1,3-,1,5-或1,6-二羰基化合物。通过顺序加成和分子内环化反应,一步一步合成2-芳基苯并[ b ]呋喃已成功探索了所开发方法的范围。该方法学接受了广泛的底物,并适用于文库合成。