A new anion relay enabled [3 + 3]-annulation of active methylene isocyanides and conjugated ene-yne-ketones was developed for the efficient and straightforward synthesis of biologically valuable furo[3,2-c]pyridine derivatives. In this transformation, a sequential through-bond and through-space anion relay chemistry cascade is involved, which is initiated by an intermolecular Michael addition. Three new bonds and two rings are sequentially constructed from readily available acyclic precursors.

An unprecedented substrate‐dependent [5+1] annulation of 2‐isocyanochalcones with nitroalkanes was developed for the efficient synthesis of functionalized quinolines and 3‐nitrodihydroquinolines. This transformation delivers both the aromatic and dihydroquinolines by selectively elimination or retention of the nitro group. Moreover, 3‐nitroquinolines and tricyclic pyrrolo[2,3‐c]quinolines were conveniently constructed from the resulting 3‐nitrodihydroquinolines through a single operation, respectively.magnified image

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A catalyst-free chemoselective trimerization reaction of readily available isocyanides is described. This domino reaction provides facile access to a wide range of 2-(indol-2-yl)-quinolines and 2-(indol-2-yl)-pyridines in moderate to excellent yields. A “head to head” heterodimerization of two isocyanides is proposed as the key step of this reaction.