Solvent-controlled divergent annulation of ynones and (iso)quinoline N-oxides: of 3-((iso)quinolin-1-yl)-4H-chromen-4-ones and 13H-isoquinolino-[2,1-a]quinolin-13-ones

An effective annulation of ynones and (iso)quinoline N-oxides was developed to deliver various functionalized 3-((iso)quinolin-1-yl)-4H-chromen-4-ones and 13H-isoquinolino[2,1-a]quinolin-13-ones in moderate to excellent yields, respectively. This protocol exhibits high regioselectivity and broad substrate scope under transitionmetal-free conditions. Moreover, the key reaction intermediate was successfully isolated and determined unambiguously by single crystal X-ray crystallography.