a tandem Friedel–Crafts‐type arylation and O‐cyclization to yield novel naphthofuranyl‐spirooxindoles in excellent yields. This method is applied to enable the efficient and highly regioselective synthesis of a small‐molecule inhibitor of the sodium channel Nav1.7 (±)‐XEN402, which is currently in a phase IIb clinical trial for the treatment of pain.
Regioselective Friedel-Crafts Reaction of Electron-Rich Benzenoid Arenes and Spiroepoxyoxindole at the Spiro-Centre: Efficient Synthesis of Benzofuroindolines and 2<i>H</i>- Spiro[benzofuran]-3,3′-oxindoles
作者:Saumen Hajra、Subrata Maity、Sayan Roy
DOI:10.1002/adsc.201600312
日期:2016.7.14
Metal triflate‐catalysed intermolecular Friedel–Crafts reactions involving electron‐rich benzenoid arenes and spiroepoxyoxindoles at the spiro‐centre have been developed for the exclusive regioselective synthesis of 3‐aryl‐(3‐hydroxymethyl)oxindoles with an all‐carbon quaternary centre. Selective ring opening of spiroepoxyoxindoles with phenols provided a direct access to 3‐(hydroxymethyl)‐3‐(2‐hydroxyaryl)oxindoles
Brønsted Acid Promoted Regioselective C-3 Arylation and Heteroarylation of Spiro-epoxyoxindoles for the Construction of All Carbon Quaternary Centres: A Detailed Study
Brønstedacid promoted highly regioselective intermolecular Friedel–Crafts reactions of spiro‐epoxyoxindoles with arenes and heteroarenes has been developed in organic solvent, as well as in aqueous medium for the efficient synthesis of 3‐aryl/heteroaryl‐3‐hydroxymethyl oxindoles with all‐carbon quaternary centre, which are advanced and versatile precursors for a wide range of indole alkaloids.
Feedback Inhibition in Chemical Catalysis Leads the Dynamic Kinetic to Kinetic Resolution in C3-Indolylation of Spiro-epoxyoxindoles
作者:Saumen Hajra、Sayan Roy
DOI:10.1021/acs.orglett.0c00028
日期:2020.2.21
The first feedback inhibition, similar to enzyme catalysis, in the Co(III)salen-catalyzed asymmetric ring-opening reaction of N-free spiro-epoxyoxyindole has been discovered, which leads dynamic kinetic to kinetic resolution. This is the first report of the enantioselective construction of all carbon quaternary center from any epoxide employing metal-salen catalyst until date. This protocol provides
Efficient Synthesis of 3,3′-Mixed Bisindoles via Lewis Acid Catalyzed Reaction of Spiro-epoxyoxindoles and Indoles
作者:Saumen Hajra、Subrata Maity、Ramkrishna Maity
DOI:10.1021/acs.orglett.5b01432
日期:2015.7.17
An efficient strategy for the synthesis of 3-(3-indolyl)-oxindole-3-methanol has been developed to achieve a Lewis acid catalyzed, highlyregioselective ring opening of spiro-epoxyoxindoles with indoles. The method is used for the gram-scale formaltotalsynthesis of (±)-gliocladin C.