Gold(I)-catalyzed 6-endo-dig hydrative cyclization of an alkyne-tethered ynamide: Access to 1,6-dihydropyridin-2(3H)ones

Abstract

Hydrate your chemistry! Hydrative cyclization of 5-yne-ynamides in the presence of Echavarren's catalyst and p-toluenesulphonic acid (PTSA)×H2O at room temperature affords an array of 1,6-dihydropyridin-2(3H)one derivatives. Isomerization, epoxidation, and hydrogenation of the double bond and insertion of an extended π-conjugate system into the pyridinone skeleton have been successfully accomplished (see scheme; Ts=tosyl). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.