Ruthenium-Catalyzed Regioselective Alkenylation/Tandem Hydroamidative Cyclization of Unmasked Quinazolinones Using Terminal Alkynes

Abstract

Ruthenium-catalyzed amide directed C_sp2–H activation of the quinazolinone scaffold has been demonstrated, leading to the selective mono- or dialkenylation in moderate to good yields to achieve medicinally important stilbene containing quinazolinones. The terminal alkyne is utilized as a coupling partner, which resulted in the selective <i>trans</i>-alkene formation. Electron-deficient phenylacetylenes facilitate alkenylation followed by tandem hydroamidation of the newly generated <i>trans</i>-double bond to provide novel quinazolinone alkaloids related to the Luotonine class of natural products