Rh(iii)-catalyzed cascade cyclization of enaminones with diazo compounds: switchable syntheses of 2-pyrones and pyrido-quinazolinones

Abstract

The Rh-catalyzed C–H activation of N-pyridinyl enaminones and cascade cyclization with diazo compounds are reported to construct 2-pyrones and pyrido-quinazolinones with a broad range of substrates and good yields. The use of NaOAc as the additive and HFIP as the solvent affords 2-pyrones via C–H bond activation, enolization type conversion and cyclization. On the other hand, the use of NaOPiv and AgNTf₂ as the additives and TFE as the solvent leads to pyrido-quinazolinones based on C–H bond activation, Knoevenagel condensation, aromatization and cyclization.