Palladium-Catalyzed\nTandem Cyclization of Functional\nDiarylalkynes and Isocyanides for the Assembly of Isochromeno[4,3‑<i>c</i>]quinolines

A novel strategy for the synthesis of various isochromeno[4,3-<i>c</i>]quinolines via palladium-catalyzed tandem cyclization\nof functional diarylalkynes with isocyanides has been developed. This\napproach features excellent chemo- and regioselectivities as well\nas good functional group tolerance. Notably, 6-phenylimino-6<i>H</i>-isochromeno[4,3-<i>c</i>]quinolin-11-amines\nand 11-amino-6<i>H</i>-isochromeno[4,3-<i>c</i>]quinolin-6-ones can be selectively constructed by employing different\nprotecting groups of functional diarylalkynes. The gram-scale and\nlate-stage modifications further demonstrate the synthetic value of\nthis method.