A new route to N-aromatic heterocycles from the hydrogenation of diesters in the presence of anilines. Issue 10 (17th August 2017)

• Record Type: Journal Article
• Authors: Shi, Yiping; Kamer, Paul C. J.; Cole-Hamilton, David J.; Harvie, Michelle; Baxter, Emma F.; Lim, Kate J. C.; Pogorzelec, Peter
• Is Part Of: Chemical science. Volume 8:Issue 10(2017)
• Page Start: 6911
• Page End: 6917
• Publication Date: 2017-08-17
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7sc01718a
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : The hydrogenation of dicarboxylic acids and their esters in the presence of anilines provides a new synthesis of heterocycles. Abstract : The hydrogenation of dicarboxylic acids and their esters in the presence of anilines provides a new synthesis of heterocycles. [Ru(acac)3 ] and 1, 1, 1-tris(diphenylphosphinomethyl)ethane (triphos) gave good to excellent yields of the cyclic amines at 220 °C. When aqueous ammonia was used with dimethyl 1, 6-hexadienoic acid, ε-caprolactam was obtained in good yield. A side reaction involving alkylation of the amine by methanol was suppressed by using diesters derived from longer chain and branched alcohols. Hydrogenation of optically pure diesters (dimethyl ( R )-2-methylbutanedioate and dimethyl ( S )-2-methylbutanedioate) with aniline afforded racemic 3-methyl-1-phenylpyrrolidine in 78% yield.